呼叫保持(Call Hold)服務(wù)使用戶可暫停接收已建立的IP多媒體會(huì)話的媒體流,并在稍后恢復(fù);
*此多用于需與現(xiàn)場(chǎng)進(jìn)行交流,同時(shí)保持電話連接,暫停通話 的場(chǎng)景;
1.呼叫保持業(yè)務(wù)流程
參與呼叫保持的分別有終端UA1,UA2和UA3,均在CSCF上完成注冊(cè)
終端UA1完成與UA2的通話建立;
按呼叫保持(Call Hold)鍵,暫停與UA2的通話;
再按呼叫保持(Call Hold)鍵,恢復(fù)與UA2的通話
2.呼叫保持信令流程
3.呼叫保持主要信息:
3.1(A) INVITE sip:UA2@192.168.1.11:51948;transport=udp | , with session description
Via: SIP/2.0/UDP 192.168.1.2:64941;branch=z9hG4bK07ec3b4acc4a4392a7bedaa6532051dfcf;rport;transport=udp
Via: SIP/2.0/UDP 192.168.1.2:64869;branch=z9hG4bK81f111044c244f838fab83c8fc8fc263b01b1496;rport=64873
Max-Forwards: 69
Call-ID: 64b52f7a86a64c25ba59ac07f01604e8
CSeq: 42001 INVITE
To: <sip:UA2@Sharetechnote-cscf.com>
From: <sip:UA1@Sharetechnote-cscf.com>;tag=1111111111
Allow: INVITE, PRACK, UPDATE, ACK, BYE, CANCEL
Supported: 100rel
Supported: precondition
Accept-Contact: *;+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-application.ims.iari.gsma-vs";require;explicit
User-Agent: Sharetechnote-VirtualUA/3834
Content-Type: application/sdp
Content-Length: 571
Contact: <sip:UA1@192.168.1.2:64869;transport=udp>
Privacy: none
P-Asserted-Identity: <sip:UA1@Sharetechnote-cscf.com>
Record-Route: <sip:192.168.1.2;lr>
v=0
o=Sharetechnote 420 856420 IN IP4 192.168.1.2
s=-
i=A VOIP Session
c=IN IP4 192.168.1.2
t=0 0
m=audio 60000 RTP/AVP 107 97 8 0 101
b=AS:64
b=RS:800
b=RR:2400
a=ptime:20
a=maxptime:20
a=rtpmap:107 AMR-WB/16000
a=fmtp:107 octet-align=1; mode-set=2
a=rtpmap:97 AMR/8000
a=fmtp:97 octet-align=1; mode-set=7
a=rtpmap:8 PCMA/8000/1
a=rtpmap:0 PCMU/8000/1
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=mid:0
a=sendrecv
a=rtcp:60001
a=curr:qos local none
a=curr:qos remote none
a=des:qos mandatory local sendrecv
a=des:qos optional remote sendrecv
3.2(B) INVITE sip:UA2@192.168.1.11:51948;transport=udp SIP/2.0
INVITE sip:UA2@192.168.1.11:51948;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.1.2:64943;branch=z9hG4bK07ec3b4acc4a4392a7bedaa6532051dfd5;rport;transport=udp
Via: SIP/2.0/UDP 192.168.1.2:64869;branch=z9hG4bK81f111044c244f838fab83c8fc8fc263c24ec6e7;rport=64873
Max-Forwards: 69
Call-ID: 64b52f7a86a64c25ba59ac07f01604e8
CSeq: 42003 INVITE
To: <sip:UA2@Sharetechnote-cscf.com>;tag=340649356
From: <sip:UA1@Sharetechnote-cscf.com>;tag=1111111111
Allow: INVITE, PRACK, UPDATE, ACK, BYE, CANCEL
User-Agent: Sharetechnote-VirtualUA/3834
Content-Type: application/sdp
Content-Length: 321
Contact: <sip:UA1@192.168.1.2:64869;transport=udp>
Privacy: none
P-Asserted-Identity: <sip:UA1@Sharetechnote-cscf.com>
Record-Route: <sip:192.168.1.2;lr>
v=0
o=Sharetechnote 420 856422 IN IP4 192.168.1.2
s=-
i=A VOIP Session
c=IN IP4 192.168.1.2
t=0 0
m=audio 60000 RTP/AVP 8 0 101
b=AS:64
b=RS:800
b=RR:2400
a=ptime:20
a=maxptime:20
a=rtpmap:8 PCMA/8000/1
a=rtpmap:0 PCMU/8000/1
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=mid:0
a=sendonly
a=rtcp:60001
3.3(C) INVITE sip:UA2@192.168.1.11:51948;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.1.2:64945;branch=z9hG4bK07ec3b4acc4a4392a7bedaa6532051dfd9;rport;transport=udp
Via: SIP/2.0/UDP 192.168.1.2:64869;branch=z9hG4bK81f111044c244f838fab83c8fc8fc263a57af679;rport=64873
Max-Forwards: 69
Call-ID: 64b52f7a86a64c25ba59ac07f01604e8
CSeq: 42004 INVITE
To: <sip:UA2@Sharetechnote-cscf.com>;tag=340649356
From: <sip:UA1@Sharetechnote-cscf.com>;tag=1111111111
Allow: INVITE, PRACK, UPDATE, ACK, BYE, CANCEL
User-Agent: Sharetechnote-VirtualUA/3834
Content-Type: application/sdp
Content-Length: 321
Contact: <sip:UA1@192.168.1.2:64869;transport=udp>
Privacy: none
P-Asserted-Identity: <sip:UA1@Sharetechnote-cscf.com>
Record-Route: <sip:192.168.1.2;lr>
v=0
o=Sharetechnote 420 856424 IN IP4 192.168.1.2
s=-
i=A VOIP Session
c=IN IP4 192.168.1.2
t=0 0
m=audio 60000 RTP/AVP 8 0 101
b=AS:64
b=RS:800
b=RR:2400
a=ptime:20
a=maxptime:20
a=rtpmap:8 PCMA/8000/1
a=rtpmap:0 PCMU/8000/1
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=mid:0
a=sendrecv
a=rtcp:60001
原文來自:http://www.sharetechnote.com
整理:kangguoying20201019
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