C H A P T E R
24
Session Recovery
With robust hardware failover and redundancy protection, any hardware or software failures on the system
can quickly be corrected. However, software failures can occur for numerous reasons, often without prior
indication.
This chapter describes the Session Recovery feature that provides seamless failover and reconstruction of
subscriber session information in the event of a hardware or software fault.
Session Recovery is a licensed Cisco feature. A separate feature license may be required. Contact your
Cisco account representative for detailed information on specific licensing requirements. For information
on installing and verifying licenses, refer to the
Managing License Keys
section of
Software Management
Operations
.
Important
This chapter includes the following sections:
•
How Session Recovery Works, page 257
•
Configuring the System to Support Session Recovery, page 259
•
Recovery Control Task Statistics, page 263
How Session Recovery Works
This section provides an overview of how this feature is implemented and the recovery process.
The Session Recovery feature provides seamless failover and reconstruction of subscriber session information
in the event of a hardware or software fault within the system preventing a fully connected user session from
being disconnected.
Session recovery is performed by mirroring key software processes (for example, session manager and AAA
manager) within the system. These mirrored processes remain in an idle state (standby-mode) wherein they
perform no processing, until they may be needed in the event of a software failure (for example, a session
manager task aborts).
There are some situations wherein session recovery may not operate properly. These include:
ASR 5500 System Administration Guide, StarOS Release 21.5
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Содержание ASR 5500
Страница 100: ...ASR 5500 System Administration Guide StarOS Release 21 5 74 System Interfaces and Ports VLANs and Management Ports ...
Страница 136: ...ASR 5500 System Administration Guide StarOS Release 21 5 110 Smart Licensing Smart Licensing Bulk Statistics ...
Страница 140: ...ASR 5500 System Administration Guide StarOS Release 21 5 114 Monitoring the System Clearing Statistics and Counters ...
Страница 260: ...ASR 5500 System Administration Guide StarOS Release 21 5 234 Routing Viewing Routing Information ...
Страница 278: ...ASR 5500 System Administration Guide StarOS Release 21 5 252 BGP MPLS VPNs VPN Related CLI Commands ...
Страница 292: ...ASR 5500 System Administration Guide StarOS Release 21 5 266 Session Recovery Sample Output for show rct stats verbose ...
Страница 324: ...ASR 5500 System Administration Guide StarOS Release 21 5 298 Interchassis Session Recovery Fallback Procedure ...
Страница 338: ...ASR 5500 System Administration Guide StarOS Release 21 5 312 Engineering Rules ECMP Groups ...
Страница 362: ...ASR 5500 System Administration Guide StarOS Release 21 5 336 StarOS Tasks Management Processes ...