Anyone use TWC SIP? Looking for config advice!

Hi Folks,

Time Warner Cable will be delivering SIP trunks to me in a few days, and I’m looking to see if anyone here has experience and perhaps a working configuration they wouldn’t mind sharing.

I’m used to getting my SIP trunks from Callcentric and types, but this TWC install is a much more engineered and coordinated affair, similar to what I’ve seen before when bringing up T1’s and such – not what I’m used to for a SIP-type product. I’ll be joining a conference bridge with the TWC project manager, installation team, etc., and would rather not look completely clueless when I’m trying to bring up the trunks.


never done it with them, but I WOULD be interested in finding out how it went, and what differences to VOIP.MS type setup there is.

I would imagine they’ll talk about bandwidth shaping at the router, and such…

I know it’s been a while, but I did want to follow up and let folks know that this ended up working out just fine. There was a decent amount of trial and error involved, but in the end I was able to configure FreePBX to use the TWC SIP trunks without any problems. I used these settings in the trunk’s SIP outgoing peer details:

host=<IP of TWC SBC>

The process for scheduling the call, coordinating with an install team, etc. was time consuming and, frankly, much more difficult than using a or callcentric – but the advantage here is that TWC owns the full path. No QoS tweaking or crossing your fingers and hoping that you have a short hop to the closest server is needed. This is provided on a completely separate cable modem from the other Internet traffic, with a completely different IP block. Call quality is as good as any PRI I’ve ever used. No dropouts, significant latency etc.

Hi @jdbn
I have the same setup going on here. Using your outgoing trunk settings I’m able to get a sip peer connection. I’m wondering what you setup for the incoming portion of the trunk? What goes in the USER Context, USER details, Register String? From what they provided me I’m thinking nothing but I’m not able to route calls to an extension. Any help would be appreciated. It’s frustrating, they have info for everything but FreePBX. Thank you!

Hi Mike,

I have nothing at all in the incoming settings - nothing under User context, user details, or register string.

I can’t remember my steps from about six months ago, but my biggest obstacle was IP routing with two NICs, and having traffic routed to the correct interface. Looking at another thread you’ve posted on, it looks like you have the TWC SBC setup with an IP on the lan, so this isn’t the problem you’re having.

Still, if you haven’t done it already, capture some packets with tcpdump and view them with Wireshark to see what’s happening on the wire when you’re attempting to receive calls. Also, I’m replying with a suggestion on your other thread.

Good luck!


Hi Jeff, I also have 2 nic’s in my PBX and I had to create a route for all the IP ranges for the second nic as well. it was a pain, as my linux skills are lacking, but pretty good service after that was realized. Different ISP, but same issues. :slight_smile: