Sparklan WVTR-141, Руководство пользователя

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system will be able to provide easy-to-manage, business-driven architecture at a cost
that is competitive with your current expenditures.
1.2 SIP – Most Popular VoIP Protocol
SIP stands for Session Initiation Protocol which an application-layer is signaling
protocol that handles the VoIP phone calls over the Internet. Unlike other VoIP
protocols, SIP handles signaling only, and leverages other SIP-related protocols to
co-work with media sessions accordingly. The simple and flexible enough architecture
brings great chances to SIP for expanding, such as Video phone calls.
Later on, we’ll introduce some terminologies that are common in the VoIP worlds,
especially SIP related. In addition, we strongly recommend the system administrator to
read other VoIP related documents, textbooks to have better understanding in order to
construct a VoIP-friendly network.
1.2.1 SIP Identities
A SIP identity (a.k.a. SIP address or SIP Account) is similar to an email address which
is used for identifying who’s who in the SIP world just like email address used for
identifying the owner. The format of a SIP identity is like an email address, presented
as SIP-Number@SIP-Service-Domain. As the expression shows, there are two major
parts in the SIP account; the SIP-Number and SIP-Service-Domain.
z
The SIP number is the first part of the SIP URI that is located in front of the “@”
symbol. A SIP number can be alphabet characters just like in an e-mail address
(johndoe@ITSP-XYZ.com for example) or numeric digits like a regular telephone
number (1234567@ITSP-ABC.com for example).
z
The SIP-Service-Domain is the domain name in a SIP URI. It is used to identify who
the service provider is. Normally, it will be the ITSP or the Internet domain name
which your company has.
1.2.2 Servers in SIP World
The architecture of SIP protocol is client-server based. Every SIP device or application
program will act as SIP client and SIP server as well. The SIP device acts as client
when sending out SIP requests, and acts as SIP server once responding to the SIP
requests.
The Servers we talk about here aim only at the device, and / or application program
which are used to provide VoIP services or application program which is used by
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