[asterisk-users] Migrating asterisk 11 to 13: some callers get no ringback tone any more

[Michael Maier]

On 05/03/2016 at 09:16 PM Joshua Colp wrote:
> Eric Wieling wrote:
>> I don't know the default setting for progressinband in the code, but it
>> is documented in Asterisk 11's sip.conf.sample as defaulting to never.
>> Maybe the docs were fixed since Asterisk 11.
> 
> The behavior change to actually do what the option was documented to do.
> As part of that the default was changed to reflect the past behavior,
> thus why it was changed to no. The commit itself:
> 
> chan_sip: make progressinband default to no
> 
> After the "progressinband" value setting of "never" was updated to never
> send a 183 this separated its use from the "no" value. 

But "never" option therefore sends 180 Ringing which I was missing. The
new default "no" doesn't send 180 Ringing any more ... .

> Since "never" was
> the default, but most users probably expect "no" this patch updates the
> default for the "progressinband" setting to "no."
> 
> This was tracked under ASTERISK-24835[1].
> 
> [1] https://issues.asterisk.org/jira/browse/ASTERISK-24835
> 

This makes sense! I migrated from

	asterisk11-11.8.1-40_centos6.x86_64,

which had the default progressinband=never to

	asterisk13-core-13.7.2-1.shmz65.1.94.x86_64

which had the new default.

POTS callers advertise support for early media - mobile callers on the
other hand don't advertise it, therefore mobile wasn't a problem because
early media (183) isn't triggered (and used!) at all.


Two strange things being left:

1. Why does progressinband=no work, if there is *no* ringgroup between
trunk and extension. This seems to be a "feature" of FreePBX.

2. Why is early media used even if the caller doesn't advertise it? Are
there other triggers like P-Early-Media?




Another basic question:
What do I need early media exactly for? I'm only using SIP phones -
nothing else. Couldn't it be completely disabled for these trunks? Or
would it break things like voice mail service e.g.? How can I disable it
completely even if it is advertised by the caller?


Thanks,
Michael