Css Considerations When Using Ess; Atm Considerations When Using Ess; Ipsi Priority List - Avaya ESS User Manual

CSS considerations when using ESS

An ESS server cannot take control of a CSS, but can control a CSS connected Port Network
where an IPSI and an IP Media Processor reside. Once an IPSI in a CSS Port Network requests
and obtains service from an ESS server, it enters into an IP-Connect mode.
The following is true for CSS in an ESS environment:
In the event of a Main server failure, the CSS will be out-of-service. This is true because
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the CSS is enabled only for the Main server(s) and disabled for all other servers.
The number and vintage of the IP Media Processor resource will have an impact on the
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traffic volume for the failed-over Port Network. Traffic engineering should consider the use
of multiple IP Media Processors to allow for adequate call volume of failed-over Port
Networks.
An ESS server can provide service to an IPSI in a mixed Port Network configuration such
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as:
- CSS and IP-Connected
- ATM-PNC and IP-Connected
Note:
CSS and ATM-PNC mixed configurations are not supported.
Note:

ATM considerations when using ESS

In an ATM environment, all ATM Expansion Interface (EI) boards must be either the TN2305B or
the TN2306B. An ESS server can control ATM Port Networks without an IPSI by communicating
indirectly through an IPSI controlled Port Network, and then through the TN2305B or TN2306B
ATM EI board.
Port Networks in an ATM environment do not transition to IP during a failover to an ESS server.

IPSI Priority List

In an ESS environment, every IPSI has a priority list that contains up to eight servers, one Main
server(s) and seven ESS servers. The IPSI uses its priority list to determine possible available
ESS servers to failover to in the event of communication loss to the Main server(s). The IPSI
places the ESS server on the priority list as each ESS server advertises its values to the IPSI.
CSS considerations when using ESS
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