2017-03-01 15:48 GMT+01:00 Sergey Basov <sergey.v.basov at gmail.com>: > 2017-03-01 15:57 GMT+02:00 Daniel-Constantin Mierla <miconda at gmail.com>: >> If yes, this is not a valid SIP message, because it lacks mandatory >> headers such as call-id, cseq, from/to. >> > Yes it is without any headers... So is not a valid SIP message