Below is a list of popular routers that you can disable the SIP ALG settings for.  Any routers not listed here please consult the manufacturers handbook or Google search your router make and model and 'how to disable SIP ALG'. 


TP Link Archer C2 Router


Access the SIP ALG on TP Link Archer C2 Router (access to user manual)

This link takes you to page 92 – but also look back to page 91 as this gives a screenshot of the screen where you will find the ALG settings.

http://www.manualslib.com/manual/721774/Tp-Link-Archer-C2.html?page=92


Netgear Routers


SIP ALG is used to try and avoid configuring Static NAT on a router. Its implementation, however, varies from one router to another, often making it difficult to inter-operate a router with SIP ALG enabled with a PBX. In general, you would want to disable SIP ALG and configure one to one port mapping on the router.


In this article, we will show you how to disable SIP ALG on a Netgear router. SIP ALG on this router is known to cause problems with VoIP calls.


Follow this step-by-step guide:


1. Open the Netgear router configuration by browsing to its LAN Address (http://192.168.0.1 by default).

2. Log in to the router’s configuration. The default username is “admin” and the default password is “password”.

3. In the main menu, select “Advanced” > “WAN Setup”.

4. Enable the option “Disable SIP ALG”.

5. Click “Apply”.


List of routers with SIP ALG enabled


The following is a list of routers with SIP ALG enabled - detailing the issues encountered and info on how to disable SIP ALG on these routers:


Dlink


Models: DIR-655


Motorola


Models: SBG6580 (SurfBoard Extreme Wireless Cable Modem Gateway)
  • No Registeration possible behind NAT as the device changes Call-ID and causes the responses to be discarded by SIP clients/ATAs
  • No Solution at this time (SIP ALG, called SIP Pass Through, can not be disabled) .
  • Must disable NAT and put the device in bridge mode. 


SpeedTouch


Models: ST530 v6(firmware >= 5.4.0.13) comes with SIP ALG enabled by default.
NAT type: symmetrical
Issues:
  • No incoming calls.
  • It replaces the private IP appearing in SIP headers with the public IP using a dumb text replacement. If for example the private IP appears in the "Call-ID" it replaces it too.

To disable SIP ALG:
  • ~# telnet router
  • -> connection unbind application=SIP port=5060
  • -> saveall


Zyxel


Models: 660 family comes with SIP ALG enabed by default.
NAT type: symmetrical
Issues:
  • No incoming calls.
  • SIP protocol broken making 50% of outgoing calls impossible because the wrong values are inserted into SIP headers.

To disable SIP ALG:
  • ~# telnet router
  • Menu option "24. System Maintenance".
  • Menu option "8. Command Interpreter Mode".
  • ip nat service sip active 0


Netgear


Models: WGR614v9 Wireless-G Router, DGN2000 Wireless-N ADSL2+ Modem Router

Firmware V1.0.18_8.0.9NA


To disable SIP ALG: 

  • From Wan Setup Menu, NAT Filtering, uncheck the box next to "Disable SIP ALG"


SMC


Models: ToDo

NAT type: No symmetrical


Issues:

  • The ALG doesn't replace the private address in "Call-ID" header (that is correct) but it does replace the "call-id" value in "Refer-To" header so SIP transfer is broken.

To disable SIP ALG: 
  • No ALG related options found via web and telnet. No idea of how to disable it.


Linksys


Models: WRV200, WRT610N

NAT type: Symmetrical


Issues:

  • The ALG replaces the private address in "Call-ID" header (not needed at all). Some phones (as Linksys with latest firmware) encode the "Call-ID" value in the "Refer-To" header (by escaping the dots) so the private IP appearing there is not replaced with the public IP. This causes that the call transfer fails since the proxy/PBX/endpoint will not recognize the dialog info.


To disable SIP ALG: ToDo no ALG related options found via web and telnet. No idea of how to disable it.

To disable SIP ALG on WRT610N: Web Interface: Administration, Management, under side heading 'Advanced Features' SIP ALG, can be disabled.


Peplink Multi-WAN routers


Models: All multi-WAN models


To disable SIP ALG, go to http://<router.LAN.IP>/cgi-bin/MANGA/support.cgi

Click the "Disable" button under "SIP ALG Support"


Fortinet


Models: All models come with SIP Helper enabled by default


To disable SIP helper:

  • ~# telnet firewall
  • config system settings
  • set sip-helper disable
  • set sip-nat-trace disable
  • end
  • config system session-helper
  • show <---- use this to find out which entry is configured for typically 12 or 13
  • delete 12
  • end
  • The preferred solution is to configure the SIP ALG. Policies that use the SIP ALG will not use SIP helper. Full documentation at http://docs.fortinet.com then pick FortiOS for the version on your device, then VoIP solutions: SIP.


Cisco


Models: 800 Series

To disable the NAT services for SIP in IOS, just run these commands:

  • no ip nat service sip tcp port 5060
  • no ip nat service sip udp port 5060


Juniper / Netscreen


Models: SSG Series


To disable SIP ALG:

  •  In the Web interface: Security -> ALG

Please note: 

Please check you have 'saved' the settings on the router and then 're-boot' the router for the setting to take effect.