Reliability and Recovery
ESS System Capacities
ESS can be administered as “local only” or as an
For
Depending on the type of failure and how the ESS servers are configured, an individual ESS server may accept control of all port networks, several port networks, a single port network, or no port networks. When a LAN or WAN failure occurs in configurations where port networks are widely dispersed, multiple ESS servers may be required to collectively accept control with each ESS server controlling some portion of the set of port networks.
When an ESS server accepts control, it communicates directly with each MCC1, CMC1, SCC1, G600, or G650 Media Gateway through the gateway’s IPSI board. In ATM PNC configuration, the ESS server can also control
Stable calls remain up in the same state as they were before the outage occurred. The stable calls do not have access to any features such as hold, conference, etc. The state of the stable call cannot be changed.
ESS and H.248 Media Gateways
The H.248 G700/G350/G250/G150 Media Gateways are not directly supported by the ESS feature. In the event of a failure they may
ESS and Adjunct Survivability
Most adjuncts register with CLAN, which in the event of failure will follow the port network IPSI to an ESS. If the port network containing the CLAN cannot get service from an ESS, then the adjunct will not be survivable. Having CLAN in IPSI connected port networks will give the adjunct higher probability of survival.
