VOIP timeout behind Cisco ASA after Duplicate ACK and Retransmissions We have a RingCentral Polycom VVX series VOIP phone behind a Cisco ASA 5506 that will provision, work for about five minutes, go off-line for 20 minutes then reconnect and continue to work unless powered down. The problem can be duplicated and happens at multiple sites with the same configuration. A review of the packet capture shows that the system disconnects when there are a series of duplicate ACK followed by duplicate retransmissions. After about 20 minutes a RST is sent and all is well. This is the filtered capture from power on until reset -- phone is at 192.168.254.106 and RingCentral server is at 104.245.57.130. Any thoughts on problem and solution? ![packet capture](

I see that when the traffic goes south, the TSval of the packets rolls over the 2^32 mark and starts again at 0, but the ASA is ACKing back a TSecr of a very high number. It looks like you were hitting Cisco bug ID CSCuq80704. You were running 9.6(2), which was an affected version, and 9.8(2) was a fixed version.

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