Identifying details anonymized. Dialing muliple 10 digit North American numbers.
I don’t think it’s the PBX since nothing was changed on it as far as I know. Previous SIP messages look like normal call negotiation until this one. The end result is an all circuits busy message.
2023/04/21 11:33:24.099039 64.136.174.30:5060 -> xx.xx.xx.xx:5060
SIP/2.0 404 ERS:No Route Available
Via: SIP/2.0/UDP xx.xx.xx.xx:5060;branch=z9hG4bK34c063f5;rport=5060
To: <sip:NXXNXXXXXX@64.136.174.30>;tag=sansay845362775rdb28095
From: "test" <sip:XXX@xx.xx.xx.xx>;tag=as71b725e8
Call-ID: 6bb53879430b98251b7be52407a5dcd7@xx.xx.xx.xx:5060
CSeq: 102 INVITE
Content-Length: 0
5 posts - 2 participants