On Fri, 11 May 2018, Joshua Colp wrote:>> In the above example, even though the INVITE/SDP says they prefer gsm >> over ulaw and the OK/SDP says I prefer ulaw over gsm, they can choose >> to use gsm or ulaw? > > Yes. > >> Can it be asymmetrical? They send gsm and I send ulaw? > > Technically, yes. In practice it's a bit iffy - specifically because > some DSPs in devices won't allow it - they require a single codec be in > use for each direction.So, Asterisk will defer it's choice of codec to match the codec it detects in the incoming stream? -- Thanks in advance, ------------------------------------------------------------------------- Steve Edwards sedwards at sedwards.com Voice: +1-760-468-3867 PST https://www.linkedin.com/in/steve-edwards-4244281
On Fri, May 11, 2018, at 10:36 AM, Steve Edwards wrote:> On Fri, 11 May 2018, Joshua Colp wrote: > > >> In the above example, even though the INVITE/SDP says they prefer gsm > >> over ulaw and the OK/SDP says I prefer ulaw over gsm, they can choose > >> to use gsm or ulaw? > > > > Yes. > > > >> Can it be asymmetrical? They send gsm and I send ulaw? > > > > Technically, yes. In practice it's a bit iffy - specifically because > > some DSPs in devices won't allow it - they require a single codec be in > > use for each direction. > > So, Asterisk will defer it's choice of codec to match the codec it detects > in the incoming stream?It depends on the channel driver and configuration. The chan_sip module always matching outgoing codec to the incoming codec. The chan_pjsip module has an option to do that (which is on by default). -- Joshua Colp Digium, Inc. | Senior Software Developer 445 Jan Davis Drive NW - Huntsville, AL 35806 - US Check us out at: www.digium.com & www.asterisk.org
> On Fri, May 11, 2018, at 10:36 AM, Steve Edwards wrote: >> >> So, Asterisk will defer it's choice of codec to match the codec it detects >> in the incoming stream?On Fri, 11 May 2018, Joshua Colp wrote:> > It depends on the channel driver and configuration. The chan_sip module > always matching outgoing codec to the incoming codec. The chan_pjsip > module has an option to do that (which is on by default).Is this why I see occasional notices in my log file like: Dropping incompatible voice frame on SIP/xxx of format ulaw since our native format has changed to (gsm) -- Thanks in advance, ------------------------------------------------------------------------- Steve Edwards sedwards at sedwards.com Voice: +1-760-468-3867 PST https://www.linkedin.com/in/steve-edwards-4244281