Cisco ASR 5000 Series, Обзор продукта

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Redundancy and Availability Features
▀ Service Availability Features
▄ Cisco ASR 5000 Series Product Overview
OL-22938-02
Hardware
Failure Scenario Action Taken Effect on
Accounting Data Effect on
User
Sessions
Effect on the flow
of Data Packets Effect on Control
Transactions
Unplanned
processing card
failure, no
Session
Recovery Tasks are restarted on
standby processing card.
Network connection is
maintained on existing LC
via RCC. AAA Acct_Stop
record is
generated for all
sessions in the
affected
subgroup Sessions lost
on affected
processing
card only Lost only for the
effected sessions < 5 sec. interrupt until
new A11/GTP-C
manager is available
(new sessions
only)
NOTE: Applies
only when A11/GTP-C
manager is on failed
card
Unplanned
processing card
failure, with
Session
Recovery Sessions are recovered on
the standby processing
card. Network connection
is maintained on existing
LC via RCC No impact (less
interim update
interval) No impact < 5 sec. interrupt < 5 sec. interrupt (new
sessions only)
Unplanned LC
failure Standby LC becomes
active if installed in 1:1
redundant configuration. No impact (less
update interval) No impact < 1 sec. interrupt < 1 sec. interrupt
Unplanned LC
port failure With LC port redundancy
enabled, standby port is
enabled. No impact No impact < 1 sec. interrupt < 1 sec. interrupt
1. This does not apply to for deployments containing only 1 active processing card.
Important:
If the session recovery feature is enabled, then a processing card hardware failure will not cause any
loss of fully established HA subscriber sessions. This feature does, however, require a minimum processing card
configuration per chassis of three active cards and two standby to prevent all data loss and session recovery.
Important:
When a processing or line card failover occurs, the redundant component (when installed)
automatically begins providing service. However, once the failed card's error condition is corrected (by replacement or
configuration change), there is no automatic return of control to the repaired processing or line card. This migration
must occur through manual intervention by a system administrative user.
Software Assurance Features
Numerous features are built into the system software to ensure the continuation of service in the case of software
process failures. SMC software controls the management contexts and overall system control, while processing card
software controls the PPP sessions, AAA, and VPN processes.
The following table shows various software process failure situations involving the SMC and SPIO cards, provides
impact analysis (if any), and explains how each situation is resolved using rapid failure detection techniques found in
the system.