register sip trace from fs

Session Initiation Protocol (REGISTER)
    Request-Line: REGISTER sip:8.8.8.8;transport=udp SIP/2.0
        Method: REGISTER
        Request-URI: sip:8.8.8.8;transport=udp
            Request-URI Host Part: 8.8.8.8
        [Resent Packet: False]
    Message Header
        Via: SIP/2.0/UDP 165.21.83.88:5082;rport;branch=z9hG4bK41r47Xm3y8Nrg
            Transport: UDP
            Sent-by Address: 165.21.83.88
            Sent-by port: 5082
            RPort: rport
            Branch: z9hG4bK41r47Xm3y8Nrg
        Max-Forwards: 70
        From: <sip:username@8.8.8.8>;tag=42eFBSeQy7y6c
            SIP from address: sip:username@8.8.8.8
                SIP from address User Part: username
                SIP from address Host Part: 8.8.8.8
            SIP from tag: 42eFBSeQy7y6c
        To: <sip:username@8.8.8.8>
            SIP to address: sip:username@8.8.8.8
                SIP to address User Part: username
                SIP to address Host Part: 8.8.8.8
        Call-ID: 3dec4ac6-009b-11e6-8483-27b693757a72
        CSeq: 89892808 REGISTER
            Sequence Number: 89892808
            Method: REGISTER
        Contact: <sip:username@165.21.83.88:5082;transport=udp;gw=sip.provider.com>
            Contact URI: sip:username@165.21.83.88:5082;transport=udp;gw=sip.provider.com
                Contact URI User Part: username
                Contact URI Host Part: 165.21.83.88
                Contact URI Host Port: 5082
                Contact URI parameter: transport=udp
                Contact URI parameter: gw=sip.provider.com
        Expires: 3600
        User-Agent: Grandstream HT701 1.0.7.3
        Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY
        Supported: timer, path, replaces
        Content-Length: 0