expected_error:-5 with duplicate headers that are not multi
INVITE sip:user@company.com SIP/2.0
User-Agent: Lame Agent
Via: SIP/2.0/UDP 135.180.130.133;branch=z9hG4bKkdjuw
Max-Forwards: 70
CSeq: 0 INVITE
Call-ID: 98asdh@10.1.1.2
From: sip:caller@university.edu;tag=3413415
From: sip:caller@organization.org
To: sip:user@company.com
Content-Type: application/sdp

v=0
o=mhandley 29739 7272939 IN IP4 126.5.4.3
s=-
c=IN IP4 135.180.130.88
t=0 0
m=audio 492170 RTP/AVP 0 12
m=video 3227 RTP/AVP 31
a=rtpmap:31 LPC