On 1/3/18 7:54 PM, onewhoknows wrote:
Hello,
I have an issue with some older releases of Asterisk talking to an Avaya
PBX.
I think there's a network issue somewhere, but in the meantime, I'd like to
know which side is handling the following transaction correctly:
Asterisk > Avaya
Invite >
< 100 Trying
< 200 OK
ACK
< 200 OK
< 200 OK
< 200 OK
... several more times
< 200 OK
< BYE
200 OK
The issue is intermittent and when it occurs, the far end does not see the
ACK.
My question in this particular instance is should Asterisk be responding to
each 200 OK with an ACK, or has it satisfied its part of the transaction by
sending that first ACK? Each 200 OK has the same CSEQ, branch, etc.
Asterisk is wrong. The ACK must be transmitted for each 200 OK received.
This is necessary in the case where an ACK is lost. The UAS is
retransmitting the 200 because it hasn't yet received an ACK.
You say this is intermittent, which is consistent with an ACK being lost.
Thanks,
Paul
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