Multiple 487s after cancel

Hi,

Please take a look at the following SIP dialogue:

Does anyone have an idea, why my Asterisk (1.8.20.0) sends multiple 487 Request Terminated after the customer’s Cancel? Since the third 487, the “Resent Packet” parameter in Wireshark is True - but why could those 487s be resent, when there are ACK replies for them? Can there be something wrong with those ACKs? For me it looks like my Asterisk doesn’t accept them.

Just to add: for the second leg of the call (which is made to the provider), I receive only one 487, which I reply with ACK and the dialogue is finished, what looks valid for me.

Disable pedantic mode. If it starts working, the peer is broken. Otherwise actual packet contents will be needed. Most likely the ACK is missing a tag.

Note that Asterisk SIP debugging should tell you why it is ignoring the ACK.