[*] [on-asterisk] 3CX and non Asterisk PBX users.

[Igor]

My reason for enabling SIP over TCP is for calling iPhone/SIPhone and
Android/Sipdroid - based on googling it is the only way IMHO to receive
incoming calls for those devices in Standby mode ...

-- 
Igor Ostapchenko
+1-877-OCTANIX ext:2021




On Wed, 2010-12-29 at 12:55 -0600, John Lange wrote:
> Sorry to revive a stale thread but I've been doing some work recently
> with the Cisco 9971 phone and interestingly this phone is TCP only for
> both SIP and RTP.
> 
> Since Microsoft and Cisco are both doing VOIP TCP I'm curious if there
> is actually a good reason for this or if it's just a case of the blind
> leading the blind?
> 
> As I said previously in this thread, SIP TCP _might_ make some sense
> as long as you stripped the state tracking out of the SIP protocol
> (which means it wouldn't actually be SIP anymore) but RTP over TCP?
> Madness!
> 
> I can think of only two reasons for this:
> 
> a) Microsoft doesn't know jack about SIP/RTP so they wrote it using
> TCP because they didn't know any better & Cisco wanted to be
> compatible with Microsoft.
> 
> b) Cisco firewalls aren't good at reliably tracking UDP state so they
> decided to get around the problem by using TCP.
> 
> If there is actually a good technical reason for voip over TCP I'd
> love to hear it.
>