I have a user that is getting Invalid INV when he picks up his handset to make a call. The user then has to unplug and plugin his ethernet cable to return to normal. I am also seeing the following in the asterisk error log:
[Nov 10 08:24:29] WARNING[9694] chan_sip.c: Maximum retries exceeded on transmission 00075032-57780004-60d6bad0-75ad02ca@10.11.1.66 for seqno 101 (Critical Response) – See doc/sip-retransmit.txt.
The phone becomes un responsive when this happens you can’t even telnet into the phone. Has anyone seen this before?
The phone is a Cisco 7960, when it gets the INV error, you can’t ping it or anything. I’ve been watching the SIP debug and am seeing the phone get the SIP 200 OK. I’m not sure why its fine for several hours and it just quits, it’s not doing it on any other phones. I have switched phones, jacks, switch ports, checked all the cables.