There has been a lot of buzz this week so far about Google Voice SIP addresses.. Today, however, we found in testing that Google is no longer responding to SIP traffic. While many are speculating about what Google is up to, I wanted to make a quick point about the remote client, YATE, that Google seems to have chosen to answer Google Voice SIP calls (when it was working... yesterday). First, a bit about the discovery and a great introduction to YATE by Dan York:
"What's interesting to me here is that SJphone reports that the remote client is YATE, a.k.a. Yet Another Telephony Engine. Yate has been around for a while (the voip-info wiki has some history) but hasn't been as widely known as, say, Asterisk or FreeSwitch. Looking over at the Yate News page, I see this note with regard to the January 31, 2011, release 3.1 of Yate: Yate client calls can use Google Voice service. The Yate client is a soft client for both voice and IM and in looking at their tutorial on using the client with Google Voice it would appear that this is about using XMPP (Jabber) to connect from the client over to Google Voice... but the key point here is that Google appears to have chosen Yate to use on the receiving end of SIP calls into a Google Voice number." -Dan York, Google Voice Now Offers SIP Addresses for Calling Directly over IP
We found this an interesting discovery and immediately thought we'd take a look at YATE client as a possible client to use with OnSIP. We didn't need to look too far as a member of our Support team had already installed and tested the client not too long ago. He reported that just like our findings with SIP in Gingerbread for Android, the client doesn't allow the differentiation between Auth Username and Username (RFC 3261 Section 22.1). This creates limitations and makes the client incompatible with our service.