Nortel Networks NN10029-111 사용자 설명서
Overview
5
Copyright © 2003, Nortel Networks
MCP SIP Application Module Basics
Nortel Networks Confidential
— changing IP addresses in the contact header so that the SIP
Application Module remains on the signaling path
— modifying the Session Description Protocol (SDP) using values
supplied by the RTP Media Portal to control media endpoints
— providing advanced screening capabilities
The architecture of a BBUA service consists of two user agent
clients linked back-to-back through a proprietary interface.
clients linked back-to-back through a proprietary interface.
The BBUA is guaranteed to be on the signaling path of all future
requests and responses because it is an endpoint relative to the SIP
network components. This is important for services such as billing,
which need to be aware of all events that take place on a session.
The BBUA in the network also provides a barrier for clients that are
not fully SIP compliant and entry and exit points for traffic travelling
to and from the public network, including agents behind an
enterprise firewall. See Figure 1, “Back-to-Back User Agent
service.”
requests and responses because it is an endpoint relative to the SIP
network components. This is important for services such as billing,
which need to be aware of all events that take place on a session.
The BBUA in the network also provides a barrier for clients that are
not fully SIP compliant and entry and exit points for traffic travelling
to and from the public network, including agents behind an
enterprise firewall. See Figure 1, “Back-to-Back User Agent
service.”
Figure 1 Back-to-Back User Agent service
Routing in a SIP network is based on the same hop-by-hop principle
as routing e-mail within the Internet. The next hop for a SIP request
is determined by a proxy using the domain or the host part of a SIP
URL (user@domain). The terminating proxy determines whether
the domain sent in the SIP URL is one of the domains managed by
the SIP proxy. Otherwise, the SIP request is forwarded to another
Proxy based on the location lookup performed by the
SIP Application Module. The SIP Application Module supports
routing using table lookup in the SIP database or using the Domain
Name Server (DNS) to find a route.
as routing e-mail within the Internet. The next hop for a SIP request
is determined by a proxy using the domain or the host part of a SIP
URL (user@domain). The terminating proxy determines whether
the domain sent in the SIP URL is one of the domains managed by
the SIP proxy. Otherwise, the SIP request is forwarded to another
Proxy based on the location lookup performed by the
SIP Application Module. The SIP Application Module supports
routing using table lookup in the SIP database or using the Domain
Name Server (DNS) to find a route.
userB
userA
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Internal Protocol
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