Sip; Redundancy; Management - Zhone MXK Hardware Installation Manual

SIP

Redundancy

Management

The MXK also supports Megaco, H.248.
Session Initiation Protocol (SIP) is a signaling protocol that provides a
mechanism for:
•
call establishment
•
call teardown
•
call control
•
other supplementary services in an IP network.
There are two major architectural components within SIP: the SIP user agent
(UA) and the SIP network server. The UA is the end system component
responsible to initiate and answer calls. The SIP server is the network device
that handles the signaling associated with multiple calls.
The UA itself has a client element, the User Agent Client (UAC) and a server
element, the User Agent Server (UAS). The client element initiates the calls
and the server element answers the calls. This allows peer-to-peer calls to be
made using a client-server protocol.
The main function of the SIP server is to provide name resolution and user
location, since the caller is unlikely to know the IP address or host name of the
called party, and to pass on messages to other servers or SIP endpoints. Other
functions performed by the SIP servers are redirecting, forking, and
registration.
Together these components make up a basic SIP infrastructure. Application
servers can sit above these components delivering SIP supplementary services
to end users.
The MXK supports uplink card redundancy.
When the cards boot up, they elect an active and a standby card based on their
respective weights. If an active card fails, the standby takes over and becomes
active. Note that redundancy is non-revertive. That is, a previously active card
does not become active when it starts up again.
When the standby card comes up, the active card copies over the
configuration database, routing tables, and software binaries to the standby
card. As configuration changes are made to the active card, the standby card is
automatically updated.
The MXK can be managed either in-band (VLAN tagged) on uplink Ethernet
ports, out-of-band on the 10/100 Ethernet interface, or IP on a bridge.
MXK features
MxK Hardware Installation Guide
17