Call persistence process and call Process

Call persistence process and call Process
Call persistence Flowchart
Call persistence signaling:

1) when user 1000 sends the re-INVITE message to IPBX, the call between 1000 and 1002 needs to be maintained. The Re-INVITE message carries c = IN IP4 0.0.0.0 in sdp, indicating that the re-INVITE message is a call persistence message.

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, y, 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 receives the re-INVITE request response, keeps the call between user 1000 and 1002, and plays background music for user 1002, and replies to user 1000 for confirmation message 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) User 1000 receives the IPBX send confirmation request message 200 OK and sends the ACK message to 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