Huawei U-SYS MRS6100 Technical Manual page 87

Technical Manual
U-SYS MRS6100 Media Resource Server
Via: SIP/2.0/UDP 182.20.62.2:5060
Content-Length: 0
II. Unsuccessful call flow
In an unsuccessful call flow shown in Figure 5-15, UA deletes the call in the process of
creating a session. It sends a CANCEL message that results in the call failure.
SIP SIP
SIP
terminal terminal
Figure 5-15 Unsuccessful call flow
Event 1: AS sends an INVITE request to MRS6100, containing SDP-1, the session
attribute of the remote caller SIP entity.
INVITE
sip:annc.BAU.pa%28an%3dfile%3a//welcome2%20it%3d2%20iv%3d20%29@182.2
0.60.1 SIP/2.0
From: <sip:1@182.20.62.2>;tag=5220000
To:sip:annc.BAU.pa%28an%3dfile%3a//welcome2%20it%3d2%20iv%3d20%29@18
2.20.60.1
Contact: sip:182.20.62.2
Call-ID: 2000@182.20.62.2
CSeq: 10 INVITE
Content-Length: 214
Content-Type: application/sdp
AS AS
INVITE INVITE
100 Trying 100 Trying
180 Ringing 180 Ringing
CANCEL CANCEL
200 for CANCEL 200 for CANCEL
4XX for INVITE 4XX for INVITE
ACK ACK
Huawei Technologies Proprietary
5-62
Chapter 5 MGCP and SIP
MRS6100 MRS6100
INVITE INVITE
100 Trying 100 Trying
180 Ringing 180 Ringing
CANCEL CANCEL
200 for CANCEL 200 for CANCEL
487 for INVITE 487 for INVITE
ACK ACK