ZyXEL Communications MAX-207HW2 User Manual page 109

Chapter 10 The Service Configuration Screens
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.
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.
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 (johndoe@your-ITSP.com for
example) or numbers like a telephone number (1122334455@VoIP-provider.com
for example).
SIP Service Domain
The SIP service domain of the VoIP service provider (the company that lets you
make phone calls over the Internet) is the domain name in a SIP URI. For
example, if the SIP address is 1122334455@VoIP-provider.com, then "VoIP-
provider.com" is the SIP service domain.
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.
Use NAT
If you know the NAT router's public IP address and SIP port number, you can use
the Use NAT feature to manually configure the WiMAX Modem to use a them in the
SIP messages. This eliminates the need for STUN or a SIP ALG. You must also
configure the NAT router to forward traffic with this port number to the WiMAX
Modem.
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User's Guide