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Chapter 22 Voice
EMG6726/8726-B10A User’s Guide
226
SIP Call Progression
The following figure displays the basic steps in the setup and tear down of a SIP call. A calls B.
1
A
sends a SIP INVITE request to
B
. This message is an invitation for
B
to participate in a SIP telephone call.
2
B
sends a response indicating that the telephone is ringing.
3
B
sends an OK response after the call is answered.
4
A
then sends an ACK message to acknowledge that
B
has answered the call.
5
Now
A
and
B
exchange voice media (talk).
6
After talking,
A
hangs up and sends a BYE request.
7
B
replies with an OK response confirming receipt of the BYE request and the call is terminated.
SIP Call Progression Through Proxy Servers
Usually, the SIP UAC sets up a phone call by sending a request to the SIP proxy server. Then, the proxy
server looks up the destination to which the call should be forwarded (according to the URI requested
by the SIP UAC). The request may be forwarded to more than one proxy server before arriving at its
destination.
The response to the request goes to all the proxy servers through which the request passed, in reverse
sequence. Once the session is set up, session traffic is sent between the UAs directly, bypassing all the
proxy servers in between.
The following figure shows the SIP and session traffic flow between the user agents (
UA 1
and
UA 2
) and
the proxy servers (this example shows two proxy servers,
PROXY 1
and
PROXY 2
).
Table 100 SIP Call Progression
A
B
1. INVITE
2. Ringing
3. OK
4. ACK
5.Dialogue (voice traffic)
6. BYE
7. OK
Содержание EMG6726-B10A
Страница 16: ...16 PART I User s Guide...
Страница 26: ...Chapter 1 Introducing the EMG EMG6726 8726 B10A User s Guide 26 Figure 10 Wall Mounting Example...
Страница 36: ...Chapter 3 Quick Start EMG6726 8726 B10A User s Guide 36 Figure 18 Quick Start Result Summary...
Страница 59: ...59 PART II Technical Reference...
Страница 83: ...Chapter 7 Wireless EMG6726 8726 B10A User s Guide 83 Figure 35 Network Setting Wireless Advanced...
Страница 86: ...Chapter 7 Wireless EMG6726 8726 B10A User s Guide 86 Figure 36 Network Setting Wireless Channel Status...
Страница 141: ...Chapter 10 Quality of Service QoS EMG6726 8726 B10A User s Guide 141 Figure 85 Classification Setup Add Edit...
Страница 211: ...Chapter 22 Voice EMG6726 8726 B10A User s Guide 211 Figure 141 VoIP SIP SIP Account Add new account Edit...
Страница 216: ...Chapter 22 Voice EMG6726 8726 B10A User s Guide 216 Figure 143 VoIP SIP SIP Service Provider Add New Provider Edit...
Страница 279: ...279 PART III Appendices Appendices contain general information Some information may not apply to your device...