Ive got a technicolour tg582n pro router that ive disabled SIP ALG on (as per my voip providers request).

To do this on this model of router i followed this guide online where you telnet into the router run a command (although it has a browser based dashboard SIP ALG isn't accessable from there), i believe I've disabled it correctly as i didn't get any error message up when doing it, but cant be 100% sure.

Is there a test i can do to check is SIP ALG is disabled on my router ? Ive found some online Java applets that seem to test this but when ever i click to use them they all need complete access to the computer to run, which im not happy doing as i have know idea who these sites are. Is there another way it can be tested either through a telnet query or somthing similar ?


There's no quick test - you would need to be able to examine the SIP packets after they've been sent by the router to the host system, and see if the payload has been tinkered with.

Ask your SIP provider - these days many of them have a way of testing for the ALG, some even put it on their "dashboard". Or call their tech support and ask them to confirm.

Or just connect the phone and make some calls - you'll soon find out if the SIP ALG is still active, you'll get one-way audio or other issues.

NOTE that most routers where you have to use a COMMAND LINE rather than web or text menu to change a config, they often don't confirm the command, rather, they only react if there's an error, if the only response is a fresh prompt for the next command that generally means your last command was understood and acted upon. I'm not familiar with the Technicolour but I believe it is possible to disable (successufully) the ALG.

Check the manual for a "status check" command, i.e. "is the ALG active?" rather than "set it active/inactive". Often the same command but without the 1/0 value.

Also be warned with some routers where you have to use the command line to do this, the setting is lost when the router reboots and you have to do it again.

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