Redundancy - Nokia 7210 Configuration Manual

System Management
6.2.1.1
Redundancy features enable duplication of data elements to maintain service
continuation in case of outages or component failure.
6.2.1.1.1
Software outages are challenging even when baseline hardware redundancy is in
place. A balance should be maintained when providing HA routing, otherwise router
problems typically propagate not only throughout the service provider network, but
also externally to other connected networks that potentially belong to other service
providers. This could affect customers on a broad scale. The 7210 SAS-R6 and
7210 SAS-R12 devices support several software availability features that contribute
to the percentage of time that a router is available to process and forward traffic.
All routing protocols specify minimum time intervals in which the peer device must
receive an acknowledgment before it disconnects the session.
Therefore, router software must recover faster than the specified time interval to
maintain up time.
6.2.1.1.2
Features configured on the active device CFM or CPM are also saved on the standby
CFM or CPM. If the active device CFM or CPM fails, these features are brought up
on the standby device that takes over the mastership and becomes the active CFM
or CPM.
Even with modern modular and stable software, the failure of route processor
hardware or software can cause the router to reboot or cause other service impacting
events. In the best circumstances, failure leads to the initialization of a redundant
route processor, which hosts the standby software configuration, to become the
active processor. The following options are available:
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Redundancy

Software Redundancy on 7210 SAS-R6 and 7210 SAS-R12
• OSPF default session timeout is approximately 40 seconds. The timeout
intervals are configurable.
• BGP default session timeout is approximately 120 seconds. The timeout
intervals are configurable.
Configuration Redundancy on 7210 SAS-R6 and 7210 SAS-R12
• warm standby
Use subject to Terms available at: www.nokia.com
7210 SAS-M, T, R6, R12, Mxp, Sx, S Basic System
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Configuration Guide
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