Cisco C20 Codec loosing its connectivity frequently

[harshar]

Issue: Cisco C20 codec is loosing its connectivity with VCS frequently, its registering and UN-registering frequently (At least 30 times in a day).

Note: All our endpoints directly registered to VCS and managed by TMS.

Logs reference: Event log from the codec.

Checks: Network configuration, configuration of codec, Wiring everything looks good.

Log: 

SipStack ERROR: Failed to find flow for outbound proxy 

 21414.41 SipStack I: Failed to find new default outbound proxy at present time.

[Wayne DeNardi]

Is it only one particular endpoint, or one particular location that this is occurring at?

I've seen similar happen on a few occasions.   One where the bandwidth at the site the endpoint was at was getting fully utilised so the call signalling traffic was being dropped (as there was insufficient QoS policies configured), and another when there was someone trying to configure another device on the network where they had configured the same IP address on that piece of equipment as was already on the endpoint, causing an IP conflict.  The last option could be that the device has a faulty NIC.   If you have it covered by an active service contract, you can log a call with the TAC to get it replaced (if that is indeed the issue).  But as the C20 goes completely End of Support on 31 August 2018 (the end of this month), you will need to be quick if you need to do so.  Moving forward, as the C20 will be an unsupported device, the ideal option would be to replace it with something more current.