Cisco Systems ASR 1000 manual SSO Support, Issu Support, 10-3

Chapter 10 High Availability Support

SSO Support

Upon an RPR-based RP switchover event, all SBC calls already established (in a steady state) at the time of the switchover are lost. Some SBC calls in the process of being established at the time of the switchover are dropped as gracefully as possible. No new calls can be established briefly after the initial switchover event. An SBC call reconciliation takes place after an RPR-based RP switchover to ensure that both RP and Embedded Services Processor (ESP) are in sync.

RPR redundancy can allow for IOS fast software upgrades when ISSU is unavailable. In RPR mode, no Cisco IOS SBC state information is synchronized to the standby RP. Therefore, all calls are dropped upon an RPR-based switchover.

Note RPR is supported on the Cisco ASR 1000 Series Routers while RPR+ is not. You can use Stateful Switchover (SSO) instead of RPR+.

SSO Support

Integrated Session Border Controller support for Stateful Switchover (SSO) allows for stateful IOS process switchovers where critical state information is synchronized between one Route Processor used as the active processor and the other RP used as the standby processor. When Cisco IOS is configured for SSO, the SBC module running on the active IOS process constantly “replicates” its internal state to its standby peer SBC module on the standby IOS process. In this way, the standby SBC module is kept in sync with the active IOS process and has all the state information necessary to retain active calls and resume call processing in the event the active IOS process fails and an SSO occurs.

For information on SSO, see the Cisco IOS High Availability Configuration Guide at http://www.cisco.com/en/US/products/ps6922/products_installation_and_configuration_guides_list.ht ml.

ISSU Support

Integrated Session Border Controller supports In-Service Software Upgrade (ISSU) with a redundant RP or redundant IOS process. The ISSU process allows software to be updated or otherwise modified on a standby RP or standby IOS process while packet forwarding on the active RP or active IOS process continues. For the Cisco ASR 1000 Series Routers, ISSU compatibility depends on the software package being upgraded and the hardware configuration.

See the “High Availability Overview” section in the Cisco ASR 1000 Aggregation Services Router Software Configuration Guide for more, updated information on ISSU compatibility.

For information on the ISSU process, see the Cisco IOS In Service Software Upgrade and Enhanced Fast Software Upgrade Process document at: http://www.cisco.com/en/US/docs/ios/12_2sb/feature/guide/sb_issu.html.

Cisco IOS XE Integrated Session Border Controller Configuration Guide for the Cisco ASR 1000 Series Aggregation Services Routers

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