asterisk users - Sep 2005 - asterisk, SIP, Re-INVITEs and different contexts

Hmmm... Folks, I beg you pardon, if I'm telling something which was said 
before, but actually I have not found this anywhere, neither on 
Voip-info.org or in several Asterisk's docs.

So, here is the statement:

If SIP extensions are in DIFFERENT CONTEXTS, then RTP traffic between them 
will ALWAYS go via Asterisk.

I.e. Asterisk WILL NOT issue Re-INVITE even if:

 1. Both UAs have canreinvite=yes in their SIP.CONF
 2. Both UAs have same codecs
 3. There are no t, T settings in Dial command.

I'd like to have a confirmation from * developers about this statement.

I.N.

Hello!

Hmmm... Folks, I beg you pardon, if I'm telling something which was said 
before, but actually I have not found this anywhere, neither on 
Voip-info.org or in several Asterisk's docs.

So, here is the statement:

If SIP extensions are in DIFFERENT CONTEXTS, then RTP traffic between them 
will ALWAYS go via Asterisk.

I.e. Asterisk WILL NOT issue Re-INVITE even if:

 1. Both UAs have canreinvite=yes in their SIP.CONF
 2. Both UAs have same codecs
 3. There are no t, T settings in Dial command.

I'd like to have a confirmation from * developers about this statement.


I.N.

Irakli Natsvlishvili wrote:
> If SIP extensions are in DIFFERENT CONTEXTS, then RTP traffic between
> them will ALWAYS go via Asterisk.
Dial plan contexts has nothing to do with how we set up RTP traffic.
> I.e. Asterisk WILL NOT issue Re-INVITE even if:
> 
> 1. Both UAs have canreinvite=yes in their SIP.CONF
If canreinvite=yes, we *will* issue a re-invite if
possible.
> 2. Both UAs have same codecs
> 3. There are no t, T settings in Dial command.
Or h,H or nat=yes.

It is easier to turn it around:
Asterisk will issue a re-invite unless there is a reason
to keep the audio going through Asterisk

* NAT traversal issues
* Canreinvite=no
* Anything that needs asterisk to listen for DTMF in call
* Codecs that needs to be transcoded

/Olle

---
Astricon 2005 - where you will learn about Asterisk and re-invites!
http://www.astricon.net/2005/ October 12-14 Anaheim, California