User's Manual

Configuration 89

Nortel Networks Confidential

Each NSD bean describes the network interfaces and protocols to be

managed by the service being deployed under normal operating

conditions. Configuration of the servers in the active-standby group

occurs independently. The system manager is not aware of any

relationship between the servers. Therefore, take care to configure the

server group so that the reliability service functions properly.

When using the reliability manager, the administrator must ensure that

conflicts with other managed-objects do not occur. Configuration data

for the reliability manager replaces similar configuration data that may

have previously been found in the configuration data of other

managed-objects. The reliability manager internally launches network

services by communicating with other managed-objects in the system

(through the service registry). The reliability manager passes this data

to the transport controller during system initialization and state

transitions.

When provisioning for reliability, leave the SIP transport parameters in

the SIP Configuration tab blank. A set of equivalent fields are

provisioned in the Transport Management dialog box instead. All other

provisioning is unaffected.

The SIP Application Module, when running in reliable mode, requires

public and private service addresses for each service instance (a

service instance is a “virtual” application server that can exist on one of

any number of physical servers). These service addresses are what

other clients and servers use to communicate with the application

server instances (note that the Management Module is configured to

use the static addresses of the previous section).

A 1+1 reliable SIP Application Module configuration (one active and

one standby server with one service instance) needs seven addresses

on the public network and seven addresses on the private network

(total for both servers).

Configuration of the NSD is what defines those SIP Application Module

network services that require reliability. If there are two physical servers

in a 1+1 configuration, there must be one active NSD. Each active NSD

describes the SIP services to activate on an active server. The servers

in the group negotiate which NSDs each will activate. The server that

finds all NSDs already activated automatically becomes a standby

server.

Each enabled NSD must define a unique public and private service

address and may define other instance specific properties. Note that

the public and private service address tag values (their provisioned IP

addresses) should be different from the provisioned static addresses.