Chapter 15 VoIP
B222s User’s Guide
139
3
Client device A then sends the call invitation to client device C.
Figure 78
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 3550 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 56
SIP Call Progression
A
B
1. INVITE
2. Ringing
3. OK
4. ACK
5.Dialogue (voice traffic)
6. BYE
7. OK
1
2
3
A
B
C
Summary of Contents for B222s
Page 4: ...Contents Overview B222s User s Guide 4 ...
Page 12: ...Table of Contents B222s User s Guide 12 ...
Page 13: ...13 PART I User s Guide ...
Page 14: ...14 ...
Page 28: ...28 ...
Page 78: ...Chapter 7 Routing B222s User s Guide 78 ...
Page 82: ...Chapter 8 DNS Route B222s User s Guide 82 ...
Page 102: ...Chapter 10 Network Address Translation NAT B222s User s Guide 102 ...
Page 114: ...Chapter 12 Firewall B222s User s Guide 114 ...
Page 120: ...Chapter 14 Parental Control B222s User s Guide 120 ...
Page 125: ...Chapter 15 VoIP B222s User s Guide 125 ...
Page 144: ...Chapter 15 VoIP B222s User s Guide 144 ...
Page 154: ...Chapter 17 Traffic Status B222s User s Guide 154 ...
Page 156: ...Chapter 18 User Account B222s User s Guide 156 ...
Page 170: ...Chapter 24 Backup Restore B222s User s Guide 170 ...
Page 172: ...Chapter 25 Diagnostic B222s User s Guide 172 ...
Page 218: ...Appendix B Setting Up Your Computer s IP Address B222s User s Guide 218 ...
Page 228: ...Appendix C Pop up Windows JavaScript and Java Permissions B222s User s Guide 228 ...
Page 252: ...Appendix E Common Services B222s User s Guide 252 ...