I have been trying to make my wireless VoIP phone work properly at home, where my ISP gave me the Thomson TG585 v8 ADSL modem/router, but despite my best efforts, the phone would not connect to the SIP registrar/server/proxy.
I thus started digging the internet for a possible solution (or not) and whether I can make this finally work or be forced to change ADSL router. I also have a Netgear DGN2000 as a backup router but I prefer the Thomson as it seems to connect to my ISP at higher speeds.
Following my search, I found out that the modem has an internal SIP service running that messes up the SIP/VoIP packets, and a possible solution is to disable that service. Then, I stumbled on this site that shows how to Telnet the modem/router and change some settings. It seems that if you login via PuTTY or Terminal.app and enter the same credentials as the router’s WebUI, with a simple command you can disable the SIP service:
connection unbind application=SIP port=5060
The first command unbinds the service from the (default) port for SIP/VoIP and the second command saves the settings to the flash memory. After a necessary soft reboot of the modem/router, the wireless VoIP phone works and successfully connects with my provider’s registrar/proxy!
To revert/undo the change above, simply Telnet again the router and type:
connection bind application=SIP port=5060
…and reboot the modem/router for the change to take effect.
There is a CLI Reference Guide available for this Thomson router that contains all available commands and what they do, for using via Telnet. I got the latest version (v8) from here.
For example, you can display the IP address of the DNS server entries of the modem/router (as provided by the ISP):
dns server route list
This Telnet functionality was a really interesting find…