> 5. (issue) My IVR system ACKs the 200ok and 2-4ms > later sends the refer. Because these transmissions > are using different TCP connections sometimes > the REFER is received by Avaya cm before the ACK. > This causes Avaya to decline the REFER and call to > not be transferred on occasion. > > My question here is what is the rule of thumb here?
Race conditions can happen. Some vendors will attempt to resolve it by queuing and others by defaulting to returning a failure such as 500 with Retry-After. And if it isn't a B2BUA (or other device with a reason to process the ACK first), the REFER can potentially be successfully processed without queuing or rejection. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
