Samsung Ubigate iBG2016 Configuration Manual page 399

SIP Call Flows
This section describes the basic SIP call flow in an SIP gateway.
SIP Gateway to SIP Gateway-Call Setup and Disconnect
Figure 28.7 shows a successful gateway-to-gateway call setup and disconnect.
The two end users are User A and User B. User A is located at PBX A, which
is connected to SIP gateway 1 via a T1/E1. User B is located at PBX B, which
is connected to SIP gateway 2 via a T1/E1. Table 28.1 briefly describes the
messages used in the call flow.
User A PBX A
1. Setup
3. Call Proceeding
9. Alerting
1-way voice path
12. Connect
13. Connect ACK
2-way voice path
19. Disconnect
20. Release
23. Release Complete
Figure 3.7 SIP Gateway-to-SIP Gateway-Call Setup and Disconnect
© SAMSUNG Electronics Co., Ltd.
GWI IP Network
2. INVITE
5. 100 Trying
8. 180 Ringing
2-way RTP channel
11. 200 OK
14. ACK
2-way RTP channel
17. BYE
21. 200 OK
Ubigate iBG2016 Configuration Guide/Ed.00
GW2
4. Setup
6. Call Proceeding
7. Alerting
1-way voice path
10. Connect
15. Connect ACK
2-way voice path
16. Disconnect
18. Release
22. Release Complete
PBX B User B
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