Can you connect an SIP phone with Twilio Endpoint? If so, how?

Question

I have an SIP phone system, based on the Linksys (Cisco) SPA942 telephones. I would like to take the existing PBX out of the equation and code a custom PBX for us using Twilio. I am familiar with Twilio and have coded many apps in the past, but the SIP functionality of Twilio is new to me.

Anyways, I have setup a domain, the ACL, and User credentials. and I have edited the phones configuration to connect to the twilio endpoint. However, the device never registers with Twilio. It sits idle attempting to register but it never has any success.

I know its not the firewall as its on an unfirewalled network connection so my suspicions are that either A) I have some settings wrong; or B) Twilio isnt geared to allow direct connection of a SIP phone directly to the system (requiring it to go through a tertiary system such as Asterisk or a Linksys PBX.

Can anyone tell me what Im doing wrong here?

Thanks, Rick

Answer 1

Twilio evangelist here.

[Update]

Twilio now supports SIP registration. Check out newer the answer from @Robert Welbourn below which links to docs that show you how to use it.

---- old answer ----

Unfortunately the answer today is B. We currently do not offer SIP registration so you cannot connect a SIP device directly to Twilio and receive inbound calls.

Hope that helps.

Answer 2

This is possible as of October 2016. See the below answer for detailed instructions or consult twilio's docs to figure it out for yourself.

Connecting an OBi (OBi202) to Twilio SIP?

Answer 3

Note that Twilio does now support SIP registration, so the previous answers are out of date. Please see https://www.twilio.com/docs/api/twilio-sip/pv-sip-registration.

Answer 4

Looks like Sean was able to get it working although the instructions a little bit confusing, and you will need to have a web server to act as an intermediary and route / format requests with the proper XML.