We have two remote locations to our hospital, one with a S100 on S100-126.96.36.199 that the trunk still works just fine. The S50 that we just upgraded to S50-188.8.131.52 the trunks will not work. We have tried removing them and recreating. We also notice that the S50 has this message reporting on the AVAYA that was never there and does not happen with the S100
SIP Reg/Opt Rx: phone
OPTIONS sip:email@example.com:5060;transport=udp SIP/2.0
Via: SIP/2.0/UDP XX.XXX.X.XXX:28123;rport;branch=z9hG4bKPjd622b361-7c40-4bdf-a604-92e05cbca236
CSeq: 63722 OPTIONS
User-Agent: Yeastar S50-184.108.40.206
How can we revert to 220.127.116.11 which was the last working firmware on the S50 or possibly 18.104.22.168 that is still working OK on the S100?