No.     Time        Source                Destination           Protocol Info
    944 23.737649   192.168.1.10          192.168.1.15          SIP      Request: REGISTER sip:192.168.1.15

Frame 944 (520 bytes on wire, 520 bytes captured)
Linux cooked capture
Internet Protocol, Src: 192.168.1.10 (192.168.1.10), Dst: 192.168.1.15 (192.168.1.15)
User Datagram Protocol, Src Port: sip (5060), Dst Port: sip (5060)
Session Initiation Protocol
    Request-Line: REGISTER sip:192.168.1.15 SIP/2.0
    Message Header
        Via: SIP/2.0/UDP 192.168.1.10;branch=z9hG4bK87461228c4133a6f
        From: <sip:+41215501111@192.168.1.15>;tag=a5870404e4bd88ff
        To: <sip:+41215501111@192.168.1.15>
        Contact: <sip:+41215501111@192.168.1.10>
        Supported: replaces
        Call-ID: 25e54494742378e1@192.168.1.10
        CSeq: 101 REGISTER
        Expires: 150
        User-Agent: Grandstream BT110 1.0.8.33
        Max-Forwards: 70
        Allow: INVITE,ACK,CANCEL,BYE,NOTIFY,REFER,OPTIONS,INFO,SUBSCRIBE
        Content-Length: 0