呼叫保持流程，呼叫流程

呼叫保持流程，呼叫流程
呼叫保持流程圖
呼叫保持信令：

1）  使用者1000發送re-INVITE訊息給IPBX，需要保持1000和1002之間的通話。Re-INVITE訊息攜帶SDP中c=IN IP4 0.0.0.0，說明該re-INVITE訊息是呼叫保持訊息。

INVITE sip:1002@192.168.50.22:5060SIP/2.0

Via: SIP/2.0/UDP192.168.50.20:9588;branch=z9hG4bK-d8754z-da66ec3fc2251561-1---d8754z-;rport

Max-Forwards: 70

Contact:<sip:1000@192.168.50.20:9588>

To: <sip:1002@192.168.50.22>;tag=54267485a

From:"1000"<sip:1000@192.168.50.22>;tag=8c7df95e

Call-ID:ZjBiM2MxNDQ3ZWNlM2JhYjAwYWEyNGJlMWE4NjZjYmQ.

CSeq: 3 INVITE

Allow: INVITE, ACK, CANCEL, OPTIONS,BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO

Content-Type: application/sdp

Supported: replaces

User-Agent: Bria Professional release2.4 stamp 49381

Content-Length: 238

 

v=0

o=hua 9 3 IN IP4 192.168.50.20

s=CounterPath Bria Professional

c=IN IP4 0.0.0.0

t=0 0

m=audio 7624 RTP/AVP 0 101

a=fmtp:101 0-15

a=rtpmap:101 telephone-event/8000

a=sendonly

a=x-rtp-session-id:84405823042846CFA4F793EB20FEB7E6

 

2） IPBX收到re-INVITE請求響應，保持使用者1000和1002之間的通話，並且給使用者1002播放背景音樂，給使用者1000回複確認訊息200 OK.

SIP/2.0 200 OK

Via: SIP/2.0/UDP192.168.50.20:9588;branch=z9hG4bK-d8754z-da66ec3fc2251561-1---d8754z-;rport

From:"1000"<sip:1000@192.168.50.22>;tag=8c7df95e

To:<sip:1002@192.168.50.22>;tag=54267485a

Call-ID:ZjBiM2MxNDQ3ZWNlM2JhYjAwYWEyNGJlMWE4NjZjYmQ.

CSeq: 3 INVITE

User-Agent: FreeSwitch

Contact:<sip:1002@192.168.50.22:5060>

Content-Type: application/sdp

Content-Length: 201

 

v=0

o=session 1639146064 1639146065 IN IP4192.168.50.22

s=play

c=IN IP4 192.168.50.22

t=0 0

m=audio 10476 RTP/AVP 0 101

a=rtpmap:0 PCMU/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-16

 

3） 使用者1000收到IPBX發送確認請求訊息200 OK，發送ACK訊息給IPBX

ACK sip:1002@192.168.50.22:5060 SIP/2.0

Via: SIP/2.0/UDP192.168.50.20:9588;branch=z9hG4bK-d8754z-ef0e4b7cfe6a7548-1---d8754z-;rport

Max-Forwards: 70

Contact:<sip:1000@192.168.50.20:9588>

To:<sip:1002@192.168.50.22>;tag=54267485a

From:"1000"<sip:1000@192.168.50.22>;tag=8c7df95e

Call-ID:ZjBiM2MxNDQ3ZWNlM2JhYjAwYWEyNGJlMWE4NjZjYmQ.

CSeq: 3 ACK

User-Agent: Bria Professional release2.4 stamp 49381

Content-Length: 0