I learned asterisk with the idea that IAX2 was the VoIP protocol, easy NAT, simple single stream connection, trunking, etc…
Times appear to be changing. SIP is everywhere.
I mostly use Teliax.com as my VoIP provider, my usual “A” quality IAX2 connection degraded to a “B” quality connection. The Teliax tech’s say for best voice quality, use SIP on their system. This is from a provider that has IAX in their name!
My other provider, FWD, has IAX2 issues, and the workaround is to use SIP.
I spent a few hours converting my asterisk box (AstLinux) to SIP for Teliax and FWD. The Teliax voice quality is improved (back to “A” quality) and the FWD problems went away.
So, why such acceleration with SIP? Is it the separate RTP stream that can be managed? Is the “SER” proxy application that supports high-volume applications. Is it the wider variety of SIP hardware? The fact that SIP is a standard and IAX2 has just started the standards process?
Clearly, an IAXy when away from the office can be a lifesaver, bouncing through NAT’s with ease, but will IAX2 just become a niche protocol?