When a Mobile Phone User Dials an Intra-Office Number on the SoftCo, Call Is Released Immediately When the Called Party Picks Up the Phone

Publication Date:  2015-07-15 Views:  437 Downloads:  0
Issue Description
In an office, the IAD208 is connected to the SoftCo5816. When an outer-office mobile phone user dials the number of a fixed-line phone under the IAD, the fixed line phone rings. When the called party picks up the phone, the call is immediately released. When the fixed-line phone user dials the number of the mobile user, the call is connected properly.

The version of the Softco5816 is V100R003C01SPC600, and the SoftCo connects to the IMS through the SIP trunk.
Handling Process
Based on analysis of IMS maintenance personnel, the IMS requires that the supported parameter does not contain timer. If timer is required, change Session-Expires value from 360 to 1800.

[0x000003c2][2013-12-18 13:43:23.34][sipstktptdhalftc.c 610]--Sip Msg Send-- 
SIP/2.0 200 OK 
Via: SIP/2.0/UDP 120.193.1.52:5060;branch=z9hG4bK0e1s65665t5sf37x22t1f47jk;Role=3;Dpt=7c22_36 
Call-ID: sbcuu4xo4xy5sn49z9sz95ns4zurjxrznxj@10.184.178.78 
From: <sip:18867856591@10.184.178.175:5060>;tag=j09u9ey2 
To: <sip:+8657455710297@ims.zj.chinamobile.com:5060;user=phone>;tag=lrfffmbg 
CSeq: 1 INVITE 
Allow: INVITE,ACK,OPTIONS,BYE,CANCEL,REGISTER,INFO,PRACK,SUBSCRIBE,NOTIFY,UPDATE,REFER,PUBLISH 
Session-Expires: 360;refresher=uas 
Supported: timer,in-band-dtmf 
P-Asserted-Identity: <sip:7297@10.194.73.146;ttl=0> 
Contact: <sip:+8657455710297@10.194.73.146:5566;user=phone> 
Content-Length: 175 
Content-Type: application/sdp 
v=0 
o=HuaweieSpaceV100R003C01SPC600B016 1918 1918 IN IP4 10.194.73.146 
s=Sip Call 
c=IN IP4 10.194.57.252 
t=0 0 
m=audio 50000 RTP/AVP 8 
a=rtpmap:8 PCMA/8000 
a=ptime:20

Run the following command on the SoftCo to set sessioninterval to 1800:
config modify sip parameter sessioninterval 1800
Root Cause
Based on the messages traced on the SoftCo, the SoftCo receives the ACK message from the IMS after sending the 200 OK message to the IMS; after about 1s, the IMS sends the BYE message and releases the call. Therefore, the cause lies in the IMS.

The messages are as follows:
  • Off-hook response message returned by the SoftCo to IMS:
[0x000003c2][2013-12-18 13:43:23.34][sipstktptdhalftc.c 610]--Sip Msg Send-- 
SIP/2.0 200 OK 
Via: SIP/2.0/UDP 120.193.1.52:5060;branch=z9hG4bK0e1s65665t5sf37x22t1f47jk;Role=3;Dpt=7c22_36 
Call-ID: sbcuu4xo4xy5sn49z9sz95ns4zurjxrznxj@10.184.178.78 
From: <sip:18867856591@10.184.178.175:5060>;tag=j09u9ey2 
To: <sip:+8657455710297@ims.zj.chinamobile.com:5060;user=phone>;tag=lrfffmbg 
CSeq: 1 INVITE 
Allow: INVITE,ACK,OPTIONS,BYE,CANCEL,REGISTER,INFO,PRACK,SUBSCRIBE,NOTIFY,UPDATE,REFER,PUBLISH 
Session-Expires: 360;refresher=uas 
Supported: timer,in-band-dtmf 
P-Asserted-Identity: <sip:7297@10.194.73.146;ttl=0> 
Contact: <sip:+8657455710297@10.194.73.146:5566;user=phone> 
Content-Length: 175 
Content-Type: application/sdp 
v=0 
o=HuaweieSpaceV100R003C01SPC600B016 1918 1918 IN IP4 10.194.73.146 
s=Sip Call 
c=IN IP4 10.194.57.252 
t=0 0 
m=audio 50000 RTP/AVP 8 
a=rtpmap:8 PCMA/8000 
a=ptime:20
  • Confirmation message received by the SoftCo from the IMS:
[0x000003c2][2013-12-18 13:43:23.51][sipstktptdhalftc.c 871]--Sip Msg Recv-- 
ACK sip:+8657455710297@10.194.73.146:5566;user=phone SIP/2.0 
Via: SIP/2.0/UDP 120.193.1.52:5060;branch=z9hG4bK67e01316je5k56lxlxef602lx;Role=3;Dpt=7c22_36 
Call-ID: sbcuu4xo4xy5sn49z9sz95ns4zurjxrznxj@10.184.178.78 
From: <sip:18867856591@10.184.178.175:5060>;tag=j09u9ey2 
To: <sip:+8657455710297@ims.zj.chinamobile.com:5060;user=phone>;tag=lrfffmbg 
CSeq: 1 ACK 
Max-Forwards: 68 
Content-Length: 0
  • Call release message received by the SoftCo from the IMS:
[0x000003c2][2013-12-18 13:43:24.95][sipstktptdhalftc.c 871]--Sip Msg Recv-- 
BYE sip:+8657455710297@10.194.73.146:5566;user=phone SIP/2.0 
Via: SIP/2.0/UDP 120.193.1.52:5060;branch=z9hG4bKll53l6esk766k55sk2555f51e;Role=3;Dpt=7c22_36 
Call-ID: sbcuu4xo4xy5sn49z9sz95ns4zurjxrznxj@10.184.178.78 
From: <sip:18867856591@10.184.178.175:5060>;tag=j09u9ey2 
To: <sip:+8657455710297@ims.zj.chinamobile.com:5060;user=phone>;tag=lrfffmbg 
CSeq: 2 BYE 
Max-Forwards: 68 
Reason: Q.850;cause=16 
P-Access-Network-Info: IEEE-802.11;"sbc-domain=sbc1.0574.zj.chinamobile.com";"ue-ip=10.194.73.146";"ue-port=5566";"location-info=10.194.73.146" 
Content-Length: 0
Suggestions
Although the call is released by the IMS, you can modify local parameters to avoid the problem.

END