diff --git a/resources/templates/provision/yealink/cp860/{$mac}.cfg b/resources/templates/provision/yealink/cp860/{$mac}.cfg
index a3626a2d72..39b0c9448b 100644
--- a/resources/templates/provision/yealink/cp860/{$mac}.cfg
+++ b/resources/templates/provision/yealink/cp860/{$mac}.cfg
@@ -116,14 +116,15 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal = 0
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.1.nat.stun_server =
-account.1.nat.stun_port = 3478
+#Configure the STUN server address.
+account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -572,14 +573,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1064,14 +1066,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1547,14 +1550,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2028,14 +2032,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/t20p/{$mac}.cfg b/resources/templates/provision/yealink/t20p/{$mac}.cfg
index c91c53baf0..d30806932c 100644
--- a/resources/templates/provision/yealink/t20p/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t20p/{$mac}.cfg
@@ -215,13 +215,13 @@ account.1.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal =
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.1.nat.stun_server =
+account.1.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.1.nat.stun_port =
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -528,13 +528,13 @@ account.2.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal =
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.2.nat.stun_server =
+account.2.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.2.nat.stun_port =
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.2.nat.udp_update_enable =
@@ -841,13 +841,13 @@ account.3.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal =
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.3.nat.stun_server =
+account.3.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.3.nat.stun_port =
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.3.nat.udp_update_enable =
@@ -1154,13 +1154,13 @@ account.4.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal =
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.4.nat.stun_server =
+account.4.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.4.nat.stun_port =
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.4.nat.udp_update_enable =
@@ -1468,13 +1468,13 @@ account.5.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal =
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.5.nat.stun_server =
+account.5.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.5.nat.stun_port =
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.5.nat.udp_update_enable =
diff --git a/resources/templates/provision/yealink/t21p/{$mac}.cfg b/resources/templates/provision/yealink/t21p/{$mac}.cfg
index f2799dae4c..28b2f58145 100644
--- a/resources/templates/provision/yealink/t21p/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t21p/{$mac}.cfg
@@ -116,14 +116,15 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal = 0
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.1.nat.stun_server =
-account.1.nat.stun_port = 3478
+#Configure the STUN server address.
+account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -572,14 +573,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1064,14 +1066,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1546,14 +1549,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2027,14 +2031,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/t22p/{$mac}.cfg b/resources/templates/provision/yealink/t22p/{$mac}.cfg
index a479bbc997..22ea946274 100644
--- a/resources/templates/provision/yealink/t22p/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t22p/{$mac}.cfg
@@ -215,13 +215,13 @@ account.1.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal =
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.1.nat.stun_server =
+account.1.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.1.nat.stun_port =
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -528,13 +528,13 @@ account.2.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal =
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.2.nat.stun_server =
+account.2.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.2.nat.stun_port =
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.2.nat.udp_update_enable =
@@ -841,13 +841,13 @@ account.3.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal =
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.3.nat.stun_server =
+account.3.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.3.nat.stun_port =
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.3.nat.udp_update_enable =
@@ -1155,13 +1155,13 @@ account.4.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal =
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.4.nat.stun_server =
+account.4.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.4.nat.stun_port =
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.4.nat.udp_update_enable =
@@ -1469,13 +1469,13 @@ account.5.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal =
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.5.nat.stun_server =
+account.5.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.5.nat.stun_port =
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.5.nat.udp_update_enable =
diff --git a/resources/templates/provision/yealink/t23g/{$mac}.cfg b/resources/templates/provision/yealink/t23g/{$mac}.cfg
index 50234dd6a6..cd544903ee 100644
--- a/resources/templates/provision/yealink/t23g/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t23g/{$mac}.cfg
@@ -116,13 +116,14 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
 account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
+#Configure the STUN server address.
 account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
 account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
@@ -572,14 +573,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1064,14 +1066,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1546,14 +1549,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2027,14 +2031,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/t23p/{$mac}.cfg b/resources/templates/provision/yealink/t23p/{$mac}.cfg
index f2799dae4c..28b2f58145 100644
--- a/resources/templates/provision/yealink/t23p/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t23p/{$mac}.cfg
@@ -116,14 +116,15 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal = 0
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.1.nat.stun_server =
-account.1.nat.stun_port = 3478
+#Configure the STUN server address.
+account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -572,14 +573,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1064,14 +1066,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1546,14 +1549,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2027,14 +2031,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/t26p/{$mac}.cfg b/resources/templates/provision/yealink/t26p/{$mac}.cfg
index fc2aac1441..291f9b51be 100644
--- a/resources/templates/provision/yealink/t26p/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t26p/{$mac}.cfg
@@ -215,13 +215,13 @@ account.1.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal =
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.1.nat.stun_server =
+account.1.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.1.nat.stun_port =
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -528,13 +528,13 @@ account.2.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal =
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.2.nat.stun_server =
+account.2.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.2.nat.stun_port =
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.2.nat.udp_update_enable =
@@ -841,13 +841,13 @@ account.3.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal =
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.3.nat.stun_server =
+account.3.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.3.nat.stun_port =
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.3.nat.udp_update_enable =
@@ -1154,13 +1154,13 @@ account.4.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal =
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.4.nat.stun_server =
+account.4.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.4.nat.stun_port =
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.4.nat.udp_update_enable =
@@ -1468,13 +1468,13 @@ account.5.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal =
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.5.nat.stun_server =
+account.5.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.5.nat.stun_port =
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.5.nat.udp_update_enable =
diff --git a/resources/templates/provision/yealink/t27p/{$mac}.cfg b/resources/templates/provision/yealink/t27p/{$mac}.cfg
index 8ab9672b41..c4b9163c17 100644
--- a/resources/templates/provision/yealink/t27p/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t27p/{$mac}.cfg
@@ -116,14 +116,15 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal = 0
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.1.nat.stun_server =
-account.1.nat.stun_port = 3478
+#Configure the STUN server address.
+account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -572,14 +573,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1064,14 +1066,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1546,14 +1549,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2027,14 +2031,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/t28p/{$mac}.cfg b/resources/templates/provision/yealink/t28p/{$mac}.cfg
index 77d689fd88..7b51513efe 100644
--- a/resources/templates/provision/yealink/t28p/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t28p/{$mac}.cfg
@@ -215,13 +215,13 @@ account.1.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal =
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.1.nat.stun_server =
+account.1.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.1.nat.stun_port =
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -528,13 +528,13 @@ account.2.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal =
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.2.nat.stun_server =
+account.2.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.2.nat.stun_port =
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.2.nat.udp_update_enable =
@@ -841,13 +841,13 @@ account.3.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal =
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.3.nat.stun_server =
+account.3.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.3.nat.stun_port =
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.3.nat.udp_update_enable =
@@ -1154,13 +1154,13 @@ account.4.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal =
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.4.nat.stun_server =
+account.4.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.4.nat.stun_port =
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.4.nat.udp_update_enable =
@@ -1468,13 +1468,13 @@ account.5.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal =
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.5.nat.stun_server =
+account.5.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.5.nat.stun_port =
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.5.nat.udp_update_enable =
diff --git a/resources/templates/provision/yealink/t29g/{$mac}.cfg b/resources/templates/provision/yealink/t29g/{$mac}.cfg
index 13b578d47b..194338f4dd 100644
--- a/resources/templates/provision/yealink/t29g/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t29g/{$mac}.cfg
@@ -116,14 +116,15 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal = 0
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.1.nat.stun_server =
-account.1.nat.stun_port = 3478
+#Configure the STUN server address.
+account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -572,14 +573,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1064,14 +1066,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1546,14 +1549,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2027,14 +2031,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/t32g/{$mac}.cfg b/resources/templates/provision/yealink/t32g/{$mac}.cfg
index 5e53d841f2..02a4496805 100644
--- a/resources/templates/provision/yealink/t32g/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t32g/{$mac}.cfg
@@ -215,13 +215,13 @@ account.1.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal =
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.1.nat.stun_server =
+account.1.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.1.nat.stun_port =
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -528,13 +528,13 @@ account.2.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal =
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.2.nat.stun_server =
+account.2.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.2.nat.stun_port =
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.2.nat.udp_update_enable =
@@ -841,13 +841,13 @@ account.3.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal =
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.3.nat.stun_server =
+account.3.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.3.nat.stun_port =
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.3.nat.udp_update_enable =
@@ -1154,13 +1154,13 @@ account.4.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal =
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.4.nat.stun_server =
+account.4.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.4.nat.stun_port =
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.4.nat.udp_update_enable =
@@ -1468,13 +1468,13 @@ account.5.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal =
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.5.nat.stun_server =
+account.5.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.5.nat.stun_port =
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.5.nat.udp_update_enable =
diff --git a/resources/templates/provision/yealink/t38g/{$mac}.cfg b/resources/templates/provision/yealink/t38g/{$mac}.cfg
index 56be52867c..8c944da42e 100644
--- a/resources/templates/provision/yealink/t38g/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t38g/{$mac}.cfg
@@ -215,13 +215,13 @@ account.1.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal =
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.1.nat.stun_server =
+account.1.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.1.nat.stun_port =
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -528,13 +528,13 @@ account.2.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal =
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.2.nat.stun_server =
+account.2.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.2.nat.stun_port =
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.2.nat.udp_update_enable =
@@ -841,13 +841,13 @@ account.3.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal =
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.3.nat.stun_server =
+account.3.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.3.nat.stun_port =
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.3.nat.udp_update_enable =
@@ -1154,13 +1154,13 @@ account.4.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal =
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.4.nat.stun_server =
+account.4.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.4.nat.stun_port =
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.4.nat.udp_update_enable =
@@ -1468,13 +1468,13 @@ account.5.compact_header_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal =
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.5.nat.stun_server =
+account.5.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.5.nat.stun_port =
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.5.nat.udp_update_enable =
diff --git a/resources/templates/provision/yealink/t41p/{$mac}.cfg b/resources/templates/provision/yealink/t41p/{$mac}.cfg
index 13b578d47b..194338f4dd 100644
--- a/resources/templates/provision/yealink/t41p/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t41p/{$mac}.cfg
@@ -116,14 +116,15 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal = 0
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.1.nat.stun_server =
-account.1.nat.stun_port = 3478
+#Configure the STUN server address.
+account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -572,14 +573,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1064,14 +1066,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1546,14 +1549,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2027,14 +2031,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/t42g/{$mac}.cfg b/resources/templates/provision/yealink/t42g/{$mac}.cfg
index 449154c0d1..fc5dd9f3fc 100644
--- a/resources/templates/provision/yealink/t42g/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t42g/{$mac}.cfg
@@ -116,14 +116,15 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal = 0
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.1.nat.stun_server =
-account.1.nat.stun_port = 3478
+#Configure the STUN server address.
+account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -572,14 +573,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1064,14 +1066,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1546,14 +1549,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2027,14 +2031,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/t46g/{$mac}.cfg b/resources/templates/provision/yealink/t46g/{$mac}.cfg
index b8fd3792e7..e5a47bfce7 100644
--- a/resources/templates/provision/yealink/t46g/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t46g/{$mac}.cfg
@@ -129,14 +129,15 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal = 0
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.1.nat.stun_server =
-account.1.nat.stun_port = 3478
+#Configure the STUN server address.
+account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -588,14 +589,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1080,14 +1082,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1562,14 +1565,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2043,14 +2047,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## X ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/t48g/{$mac}.cfg b/resources/templates/provision/yealink/t48g/{$mac}.cfg
index ba70fd2ed6..ad257d730b 100644
--- a/resources/templates/provision/yealink/t48g/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t48g/{$mac}.cfg
@@ -116,14 +116,15 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal = 0
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.1.nat.stun_server =
-account.1.nat.stun_port = 3478
+#Configure the STUN server address.
+account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -572,14 +573,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default)，2-Option，3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1064,14 +1066,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default)，2-Option，3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1545,14 +1548,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default)，2-Option，3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2026,14 +2030,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default)，2-Option，3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/t49g/{$mac}.cfg b/resources/templates/provision/yealink/t49g/{$mac}.cfg
index 89187ba759..ffe8de0171 100644
--- a/resources/templates/provision/yealink/t49g/{$mac}.cfg
+++ b/resources/templates/provision/yealink/t49g/{$mac}.cfg
@@ -116,14 +116,15 @@ account.1.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal = 0
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.1.nat.stun_server =
-account.1.nat.stun_port = 3478
+#Configure the STUN server address.
+account.1.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -572,14 +573,15 @@ account.2.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal = 0
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.2.nat.stun_server =
-account.2.nat.stun_port = 3478
+#Configure the STUN server address.
+account.2.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default)，2-Option，3-Notify;
 account.2.nat.udp_update_enable = 1
@@ -1064,14 +1066,15 @@ account.3.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal = 0
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.3.nat.stun_server =
-account.3.nat.stun_port = 3478
+#Configure the STUN server address.
+account.3.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default)，2-Option，3-Notify;
 account.3.nat.udp_update_enable = 1
@@ -1546,14 +1549,15 @@ account.4.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal = 0
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.4.nat.stun_server =
-account.4.nat.stun_port = 3478
+#Configure the STUN server address.
+account.4.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default)，2-Option，3-Notify;
 account.4.nat.udp_update_enable = 1
@@ -2027,14 +2031,15 @@ account.5.reg_fail_retry_interval =
 #########################################################################
 ##                     NAT Settings                                    ##
 #########################################################################
-## ranges from 1 to 6;
-##account.X.nat.nat_traversal = 0
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal = 0
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
-account.5.nat.stun_server =
-account.5.nat.stun_port = 3478
+#Configure the STUN server address.
+account.5.nat.stun_server = {$stun_server}
+
+#Configure the STUN server port, the default value is 3478.
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default)，2-Option，3-Notify;
 account.5.nat.udp_update_enable = 1
diff --git a/resources/templates/provision/yealink/vp530/{$mac}.cfg b/resources/templates/provision/yealink/vp530/{$mac}.cfg
index 2063b6c7b0..a49acc5830 100644
--- a/resources/templates/provision/yealink/vp530/{$mac}.cfg
+++ b/resources/templates/provision/yealink/vp530/{$mac}.cfg
@@ -245,13 +245,13 @@ account.1.hoteling.auto_login_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal =
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.1.nat.stun_server =
+account.1.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.1.nat.stun_port =
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -584,13 +584,13 @@ account.2.hoteling.auto_login_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal =
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.2.nat.stun_server =
+account.2.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.2.nat.stun_port =
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.2.nat.udp_update_enable =
@@ -923,13 +923,13 @@ account.3.hoteling.auto_login_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal =
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.3.nat.stun_server =
+account.3.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.3.nat.stun_port =
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.3.nat.udp_update_enable =
@@ -1262,13 +1262,13 @@ account.4.hoteling.auto_login_enable =
 #########################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal =
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.4.nat.stun_server =
+account.4.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.4.nat.stun_port =
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.4.nat.udp_update_enable =
diff --git a/resources/templates/provision/yealink/w52p/{$mac}.cfg b/resources/templates/provision/yealink/w52p/{$mac}.cfg
index f67618a0a8..f9bdd28341 100644
--- a/resources/templates/provision/yealink/w52p/{$mac}.cfg
+++ b/resources/templates/provision/yealink/w52p/{$mac}.cfg
@@ -139,13 +139,13 @@ account.1.dtmf.info_type =
 #######################################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.1.nat.nat_traversal =
+account.1.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.1.nat.stun_server =
+account.1.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.1.nat.stun_port =
+account.1.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Default (default), 2-Option, 3-Notify;
 account.1.nat.udp_update_enable = 3
@@ -380,13 +380,13 @@ account.2.dtmf.info_type =
 #######################################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.2.nat.nat_traversal =
+account.2.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.2.nat.stun_server =
+account.2.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.2.nat.stun_port =
+account.2.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.2.nat.udp_update_enable =
@@ -618,13 +618,13 @@ account.3.dtmf.info_type =
 #######################################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.3.nat.nat_traversal =
+account.3.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.3.nat.stun_server =
+account.3.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.3.nat.stun_port =
+account.3.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.3.nat.udp_update_enable =
@@ -858,13 +858,13 @@ account.4.dtmf.info_type =
 #######################################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.4.nat.nat_traversal =
+account.4.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.4.nat.stun_server =
+account.4.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.4.nat.stun_port =
+account.4.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.4.nat.udp_update_enable =
@@ -1101,13 +1101,13 @@ account.5.dtmf.info_type =
 #######################################################################################
 
 #Enable or disable the NAT traversal; 0-Disabled (default), 1-STUN;
-account.5.nat.nat_traversal =
+account.5.nat.nat_traversal = {if isset($stun_server)}1{else}0{/if}
 
 #Configure the STUN server address.
-account.5.nat.stun_server =
+account.5.nat.stun_server = {$stun_server}
 
 #Configure the STUN server port, the default value is 3478.
-account.5.nat.stun_port =
+account.5.nat.stun_port = {if isset($stun_port)}{$stun_port}{else}3478{/if}
 
 #Enable or disable the NAT keep-alive; 0-Disabled, 1-Enabled (default);
 account.5.nat.udp_update_enable =