ATM-WSP (ATM WAN Spare Processor)
Issue 1 May 2002
8-303555-233-143
Operations of the ATM WAN Spare Processors
The WSP has the following operational features:
■ The WSP feature is activated/deactivated via license file. You can verify
that ATM WSP is enabled by checking the value of the ATM WAN Spare
Processor field on the system-parameters customer-options screen.
■ Fail-over occurs when the connections with the main server and every
higher-priority WSP is lost (for an administrable period of time between 5
and 99 minutes; default = 5 minutes). When the administered threshold is
exceeded, the highest-priority standby WSP becomes active. Once the
standby WSP becomes active, it takes over control of one or more EPNs.
Restoration to the normal configuration must be manual.
■ A WSP in the standby mode is not intended to be a DCS node. Although
DCS could potentially play a role in an effective back-up or re-route
strategy, no provision has been made to support DCS connections
between parts of a failed switch. A WSP in the active mode can have the
DCS functionality of the server.
■ The main server makes no attempt to do maintenance on the WSPs.
■ A WSP can perform maintenance on itself, and monitor WAN connectivity.
■ A WSP is not recognized by the system’s hardware or software as an EPN
when not active, and functions in place of the main server when active. Up
to seven WSPs can reside in an ATM PNC configuration. The number of
EPNs in an S8700 Multi-Connect configuration is not limited by the number
of WSPs used (i.e., the number of WSPs used is not subtracted from the
total number of EPNs to determine the number of EPNs that can the
system can support).
■ Every WSP could potentially take over the entire S8700 Multi-Connect
system.
■ Links are established between the main server and each WSP, and from
every WSP to every other WSP. These links are monitored by the WSPs,
as well as by the main server, so that each processor is able to observe
and report status.
■ Each WSP is assigned a unique priority. WSPs become active if they
cannot establish communications both with the main server and with a
higher-priority WSP.
■ An active WSP attempts to establish EAL connectivity to the EPNs.
■ Contention for support of EPNs is addressed by prioritization, and also by
the fact that the EPNs accept an EAL connection to only the main server or
one WSP at a time.
NOTE:
Each WSP reports its alarms to INADS as an individual system processor.
The INADS database correlates WSPs together as part of a larger network.
To Next Page
Loading...
