AT&T uVerse blocking SIP?

Constantine A. Murenin mureninc at
Tue Jan 27 20:37:45 UTC 2015

On 26 January 2015 at 13:26, Brad Bendy <bb at> wrote:
> Has anyone seen issues where a end user on uVerse trying to connect to
> either another provider or AT&T non uVerse (in this case DIA) is having SIP
> blocked? SIP leaving the uVerse network going to another uVerse DSL account
> is fine, but it appears soon as it leave the uVerse network all SIP traffic
> is blocked?

I used to have AT&T U-verse a couple of years back.

Never had any issues with SIP.

Although I've stopped using their modem prior to starting to use SIP,
directly connecting my own router to their ONT, so, I cannot comment
on whether their 2Wire PoS is the cause of the issues you experience
(but it's indeed quite likely so).

It's worth checking with your customer whether they can throw away
their modem, too.  The modem has two ports -- green-coloured PHONE
LINE and red-coloured BROADBAND.  If they get their connection through
the green PHONE LINE port, it means it's DSL.  If it's through the red
BROADBAND port, it means no modem is required (other than every couple
of months or years for some weird port authentication that they
require), and can swap their at&t PoS with any other router.


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