[asterisk-dev] 'prematuremedia = yes' causes odd behavior on SNOM360 with early media.

[Jonathan Rose]

A little additional work revealed the following in response to this:


With the SNOM, it doesn't matter whether prematuremedia=no or yes, it
replies to the 100 Trying with an ACK.

With Blink, it doesn't ACK the 100 trying in either case.

I haven't noticed any other oddities this introduces aside from that
though.


On Fri, 2011-07-01 at 16:06 -0500, Kevin P. Fleming wrote:
> On 07/01/2011 03:55 PM, Jonathan Rose wrote:
> >
> >
> > I was tracking an issue reported by Steve Pitts against an issue which
> > involves chan_sip's premature media filter which was added in a commit
> > by oej some time ago, and I was looking for an opinion...  here's the
> > scenario.
> >
> > User calls in to Asterisk from basically any SIP phone.
> >
> > Phone to Asterisk: INVITE
> > Asterisk to Phone: 401 Unauthorized
> > Phone to Asterisk: ACK
> > Phone to Asterisk: INVITE (with credentials)
> > Asterisk to Phone: 100 Trying
> > Phone to Asterisk: ACK
> 
> This better not be what is actually happening... ACK is only sent to 
> acknowledge final responses, not provisional responses. If the phone is 
> really sending an ACK, then Asterisk should be ignoring it, as it's not 
> valid at that point in the SIP dialog.
>