RSS
Twitter
Facebook
The SIP server is used to resolve
usernames to IP addresses, so that requests sent from one user agent to another
can be directed properly.A user agent registers with the SIP server, providing
it with their username and current IP address, thereby establishing their
current location on the network.This also verifies that they are online, so
that other user agents can see whether they’re available and invite them into a
session. Because the user agent probably wouldn’t know the IP address of
another user agent, a request is made to the SIP server to invite another user
into a session.The SIP server then identifies whether the person is currently
online, and if so, compares the username to their IP address to determine their
location. If the user isn’t part of that domain, and thereby uses a different
SIP server, it will also pass on requests to other servers. In performing these
various tasks of serving client requests, the SIP server will act in any of
several different roles:
■ Registrar server
■ Proxy server
■ Redirect server
Registrar servers are used to
register the location of a user agent who has logged onto the network. It
obtains the IP address of the user and associates it with their username on the
system.This creates a directory of all those who are currently logged onto the
network, and where they are located. When someone wishes to
establish a session with one of
these users, the Registrar server’s information is referred to, thereby
identifying the IP addresses of those involved in the session.
0 comments