This could also be due to serial forking by a proxy upstream, leading to a conflicting blizzard of different progress indications from various gateways.
If you can get a capture of such a scenario and indeed find a 183 -> 180 dynamic, I'd be curious to take a look at it. Of course, there's no reason a lightweight pass-thru B2BUA in an SBC couldn't behave in a way that leads to the same result. -- Alex On Tue, Aug 20, 2019 at 12:37:19PM -0400, Pete Eisengrein wrote: > We have recently gotten several complaints about not getting, or severely > abbreviated ringback. The first few examples we were able to trace back to > a carrier and believe it is because the call sets up with 183 Session > Progress w/SDP and <1 second later get a 180 Ringing and the audible > ringing stops. > > We heard a similar complaint in Europe last with an EU carrier. And again > today with yet another US (global) provider. > > So, my questions are: > > 1- Anyone else seeing this? If so, what's your workaround/fix? > 2- Since this is not contained to a single carrier, anyone aware of an SBC > or softswitch maker recently released code that might be causing? > > Thanks, > Pete > _______________________________________________ > VoiceOps mailing list > [email protected] > https://puck.nether.net/mailman/listinfo/voiceops -- Alex Balashov | Principal | Evariste Systems LLC Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free) Web: http://www.evaristesys.com/, http://www.csrpswitch.com/ _______________________________________________ VoiceOps mailing list [email protected] https://puck.nether.net/mailman/listinfo/voiceops
