Session Recovery Feature - Cisco ASR 5000 series Product Overview

Redundancy and Availability Features
Table 24.
Software Action Taken
Process Failure
Scenario
SMC - Cleanup process
Management performs automatically,
task failure and process is restarted
SMC - System The same process for
control task unplanned hardware
failure failure (table above) is
applied
The following table shows various software process failure situations involving the processing cards, provides impact
analysis (if any), and explains how each situation is resolved using rapid failure detection techniques found in the
system.
Table 25.
Software Action Taken
Process Failure
Scenario
Processing Cleanup process
Cards - Session performs
Manager Task automatically, and
failure process is restarted
Processing Cleanup process
Cards - AAA performs
failure automatically, and
process is restarted
Processing Cleanup process
Cards - VPN performs
context failure automatically, and
process is restarted
1. This Assumes that there is more than 1 active processing card. 2. The information in this row applies to systems on which the
Session Recovery feature is not implemented. With the Session Recovery Feature enabled, no sessions are lost.

Session Recovery Feature

This licensed software feature performs an automatic recovery of all fully established subscriber sessions should a
session manager task failure occur. This functionality is available for the following call types:
OL-22938-02
Service Assurance Features for the SPC/SMC Software
Effect on
Accounting
Data
No impact
No impact
Service Assurance Features for the Processing Cards Software
Effect on
Accounting Data
AAA Acct._Stop
record is generated
for all sessions in
the affected
subgroup
No impact
No impact
Effect on Effect on the
User Flow of User
Sessions Data Packets
No impact No impact
No impact < 2 sec.
interrupt
Effect on User Sessions
Affected subgroup sessions
are lost For PSC/PSC2: up to
13200 for PDSN 13200 for
PDIF 13200 for ASN GW,
26400 for HA, and 26400
GGSN)
No impact
No impact
Cisco ASR 5000 Series Product Overview ▄
Service Availability Features ▀
Effect on User Effect on
Control Management
Transactions Traffic
No impact < 1 sec.
interrupt
No impact < 1 min.
interrupt
Effect on the Effect on
flow of Data Control
Packets Transactions
Lost only Lost only for
for the the affected
affected subgroup
subgroup
No impact No impact
< 1 sec. < 1 sec.
interrupt for interrupt for
VPN VPN context
context