javax.sip.TransactionUnavailableException: Missing a required header : Contact

[nickwu2008]

I meet one issue : it check headers fail when the sip inviter message is below: `` INVITE sip:[email protected]:8888;transport=udp SIP/2.0 Via: SIP/2.0/UDP 10.224.59.29:5060;rport=5060;branch=z9hG4bKa3d95f1d12d7b336;received=10.224.59.29 Max-Forwards: 70 To: sip:[email protected]:8888 From: sip:[email protected];user=phone;tag=a1d396220abe640c Call-ID: [email protected] CSeq: 1 INVITE Session-Expires: 1200;refresher=uac Content-Type: application/sdp Supported: timer Contact: sip:[email protected]:5060;transport=udp;ConfID=131942425935490038;WDomain=go2.qa.web.com;SiteName=go2;CEETMeetingType=3;OS=GOOGTest;MeetingKey=354359431;IsHost=1;HostName=cmFkaGEgcmFkaGE=;TssFailover=0 Content-Length: 388

v=0 o=TAS 1561604868 1561604870 IN IP4 10.224.59.29 s=- c=IN IP4 10.224.59.29 t=0 0 m=video 0 RTP/AVP 126 a=rtpmap:126 H264/90000 a=fmtp:126 profile-level-id=42e00d;packetization-mode=1;max-mbps=27000;max-fs=3600;max-dpb=5400;max-br=2000 a=content:slides a=label:12 a=inactive m=application 0 UDP/BFCP * a=floorctrl:s-only a=confid:1024 a=floorid:2 mstrm:12 a=userid:1024 `` Caused by: java.text.ParseException: Missing a required header : Contact at gov.nist.javax.sip.message.SIPRequest.checkHeaders(SIPRequest.java:318) at gov.nist.javax.sip.SipProviderImpl.getNewServerTransaction(SipProviderImpl.java:493) ... 7 more

how to fix it ?