1. Home
    2. /
  2. Manuals
    3. /
  3. Zyxel
    4. /
  4. P-2602HW-D1A
    5. /
  5. 31
Page 151 / 427 Scroll up to view Page 146 - 150
P-2602H(W)(L)-DxA Series User’s Guide
Chapter 11 Voice
151
C
HAPTER
11
Voice
This chapter provides background information on VoIP and SIP and explains how to configure
your device’s voice settings.
11.1
Introduction to VoIP
VoIP is the sending of voice signals over the Internet Protocol. This allows you to make phone
calls and send faxes over the Internet at a fraction of the cost of using the traditional circuit-
switched telephone network. You can also use servers to run telephone service applications
like PBX services and voice mail. Internet Telephony Service Provider (ITSP) companies
provide VoIP service.
Circuit-switched telephone networks require 64 kilobits per second (Kbps) in each direction to
handle a telephone call. VoIP can use advanced voice coding techniques with compression to
reduce the required bandwidth.
11.2
SIP
The Session Initiation Protocol (SIP) is an application-layer control (signaling) protocol that
handles the setting up, altering and tearing down of voice and multimedia sessions over the
Internet.
SIP signaling is separate from the media for which it handles sessions. The media that is
exchanged during the session can use a different path from that of the signaling. SIP handles
telephone calls and can interface with traditional circuit-switched telephone networks.
11.2.1
SIP Identities
A SIP account uses an identity (sometimes referred to as a SIP address). A complete SIP
identity is called a SIP URI (Uniform Resource Identifier). A SIP account's URI identifies the
SIP account in a way similar to the way an e-mail address identifies an e-mail account. The
format of a SIP identity is SIP-Number@SIP-Service-Domain.
11.2.1.1
SIP Number
The SIP number is the part of the SIP URI that comes before the “@” symbol. A SIP number
can use letters like in an e-mail address ([email protected] for example) or numbers
like a telephone number ([email protected] for example).
Page 152 / 427
P-2602H(W)(L)-DxA Series User’s Guide
152
Chapter 11 Voice
11.2.1.2
SIP Service Domain
The SIP service domain of the VoIP service provider is the domain name in a SIP URI. For
example, if the SIP address is
, then “VoIP-provider.com” is
the SIP service domain.
11.2.2
SIP Call Progression
The following figure displays the basic steps in the setup and tear down of a SIP call. A calls
B.
A sends a SIP INVITE request to B. This message is an invitation for B to participate in a SIP
telephone call.
6
B sends a response indicating that the telephone is ringing.
7
B sends an OK response after the call is answered.
8
A then sends an ACK message to acknowledge that B has answered the call.
9
Now A and B exchange voice media (talk).
10
After talking, A hangs up and sends a BYE request.
11
B replies with an OK response confirming receipt of the BYE request and the call is
terminated.
11.2.3
SIP Servers
SIP is a client-server protocol. A SIP client is an application program or device that sends SIP
requests. A SIP server responds to the SIP requests.
When you use SIP to make a VoIP call, it originates at a client and terminates at a server. A
SIP client could be a computer or a SIP phone. One device can act as both a SIP client and a
SIP server.
Table 52
SIP Call Progression
A
B
1. INVITE
2. Ringing
3. OK
4. ACK
5.Dialogue (voice traffic)
6. BYE
7. OK
Page 153 / 427
P-2602H(W)(L)-DxA Series User’s Guide
Chapter 11 Voice
153
11.2.3.1
SIP User Agent
A SIP user agent can make and receive VoIP telephone calls. This means that SIP can be used
for peer-to-peer communications even though it is a client-server protocol. In the following
figure, either A or B can act as a SIP user agent client to initiate a call. A and B can also both
act as a SIP user agent to receive the call.
Figure 84
SIP User Agent
11.2.3.2
SIP Proxy Server
A SIP proxy server receives requests from clients and forwards them to another server.
In the following example, you want to use client device A to call someone who is using client
device C.
1
The client device (A in the figure) sends a call invitation to the SIP proxy server (B).
2
The SIP proxy server forwards the call invitation to C.
Figure 85
SIP Proxy Server
Page 154 / 427
P-2602H(W)(L)-DxA Series User’s Guide
154
Chapter 11 Voice
11.2.3.3
SIP Redirect Server
A SIP redirect server accepts SIP requests, translates the destination address to an IP address
and sends the translated IP address back to the device that sent the request. Then the client
device that originally sent the request can send requests to the IP address that it received back
from the redirect server. Redirect servers do not initiate SIP requests.
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 86
SIP Redirect Server
11.2.3.4
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.
11.3
SIP Settings Screen
Use this screen to maintain basic information about each SIP account. You can also enable and
disable each SIP account. To access this screen, click
VoIP > SIP > SIP Settings
.
Page 155 / 427
P-2602H(W)(L)-DxA Series User’s Guide
Chapter 11 Voice
155
Figure 87
SIP > SIP Settings
Each field is described in the following table.
Table 53
SIP > SIP Settings
LABEL
DESCRIPTION
SIP Account
Select the SIP account you want to see in this screen. If you change this field, the
screen automatically refreshes.
SIP Settings
Active SIP
Account
Select this if you want the ZyXEL Device to use this account. Clear it if you do not
want the ZyXEL Device to use this account.
Number
Enter your SIP number. In the full SIP URI, this is the part before the @ symbol.
You can use up to 127 printable ASCII characters.
SIP Local Port
Enter the ZyXEL Device’s listening port number, if your VoIP service provider gave
you one. Otherwise, keep the default value.
SIP Server
Address
Enter the IP address or domain name of the SIP server provided by your VoIP
service provider. You can use up to 95 printable ASCII characters. It does not
matter whether the SIP server is a proxy, redirect or register server.
SIP Server Port
Enter the SIP server’s listening port number, if your VoIP service provider gave you
one. Otherwise, keep the default value.
REGISTER Server
Address
Enter the IP address or domain name of the SIP register server, if your VoIP
service provider gave you one. Otherwise, enter the same address you entered in
the
SIP Server Address
field. You can use up to 95 printable ASCII characters.
REGISTER Server
Port
Enter the SIP register server’s listening port number, if your VoIP service provider
gave you one. Otherwise, enter the same port number you entered in the
SIP
Server Port
field.

Rate

3.5 / 5 based on 2 votes.

Popular Zyxel Models

Famous Router IPs
Famous Router Companies
Bookmark Our Site

Press Ctrl + D to add this site to your favorites!

Share
Top