ESS failover examples
Issue 1.1 June 2005 49
ATM - single ESS takeover examples
In the first takeover example (see Figure 18), a catastrophic failure happens to the S8710 Main
server. The IPSIs request service of the S8500 Media Server after the no service timer expires.
The S8500 Media Server assumes control of Port Network 1, 3, 4, and 5. Once the S8500 ESS
server assumes control of the Port Network, it will attempt to take over all other Port Networks in
the system through the ATM Expansion Interface (EI) board (TN2305B or TN2306B). Since no
other servers are controlling Port Network 2 and Port Network 5, the attempt by the S8500 ESS
server to control it through ATM EI is successful.
!
Important:
Important: Port Networks in an ATM environment do not transition to IP during a failover to
an ESS server.