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Chapter 23 Voice
VMG8825-B Series User’s Guide
247
In the following example, you want to use client device
A
to call someone who is using client device
C
.
1
Client device
A
sends a call invitation for
C
to the SIP redirect server (
B
).
2
The SIP redirect server sends the invitation back to
A
with
C
’s IP address (or domain name).
3
Client device
A
then sends the call invitation to client device
C
.
Figure 150
SIP Redirect Server
SIP Register Server
A SIP register server maintains a database of SIP identity-to-IP address (or domain name) mapping. The
register server checks your user name and password when you register.
RTP
When you make a VoIP call using SIP, the RTP (Real time Transport Protocol) is used to handle voice data
transfer. See RFC 1889 for details on RTP.
Pulse Code Modulation
Pulse Code Modulation (PCM) measures analog signal amplitudes at regular time intervals and converts
them into bits.
SIP Call Progression
The following figure displays the basic steps in the setup and tear down of a SIP call. A calls B.
Table 112 SIP Call Progression
A
B
1. INVITE
2. Ringing
Содержание VMG8825-B Series
Страница 15: ...15 PART I User s Guide...
Страница 65: ...65 PART II Technical Reference...
Страница 204: ...Chapter 17 Home Connectivity VMG8825 B Series User s Guide 204 Figure 115 Network Setting Home Connectivity...
Страница 231: ...Chapter 23 Voice VMG8825 B Series User s Guide 231 Figure 139 VoIP SIP SIP Account Add new account Edit...
Страница 236: ...Chapter 23 Voice VMG8825 B Series User s Guide 236 Figure 141 VoIP SIP SIP Service Provider Add new provider Edit...
Страница 297: ...Chapter 40 Firmware Upgrade VMG8825 B Series User s Guide 297 Figure 182 Error Message...
Страница 313: ...313 PART III Appendices Appendices contain general information Some information may not apply to your device...
Страница 360: ...Index VMG8825 B Series User s Guide 360 Z ZyXEL Family Safety page 217...