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Level 1
Level 1

The Cisco Unified Border Element (CUBE) provides two types of high availability (HA) options on the Cisco Aggregation Services Router (ASR1000) platform:

  • Box-to-box redundancy
  • Inbox Redundancy

The CUBE HA implementation on the ASR Platforms supports full stateful failover for active SIP-SIP calls. This means both media and session signaling information is preserved after switchover.

This capability is supported as of Cisco IOS XE Release 3.2

Box-to-Box Redundancy

Box-to-box redundancy uses the Redundancy Group (RG) Infrastructure to form an Active/Standby pair of routers. The Active/Standby pair share the same virtual IP address (VIP) and continually exchange status messages. CUBE session information is check-pointed across the Active/Standby pair of routers enabling the Standby router to take over immediately all CUBE call processing responsibilities if the Active router should go out of service for planned or unplanned reasons.This redundancy option is supported on the ASR 1001/1002/1004 platforms.

Inbox Redundancy

Inbox redundancy mechanism provides redundancy within the same box. Some models of the ASR offers hardware redundancy within the box and some offers software redundancy. This section discusses the various aspects for Inbox Redundancy on the Cisco ASR1000 platforms.

  • Hardware redundancy – supports stateful failover from an active Enhanced Services Processor to a standby and from an active Route Processor to a standby on the same box. Cisco ASR1006 supports this type of failover
  • Software redundancy – supports stateful failover from an active IOS process to a standby process, both running on the same Route processor. This is different than the platforms running Cisco IOS like the ISR-G2s where only 1 process can run on the operating system. Cisco ASR1001/1002/1004 supports this type of failover.

This application note will provide detailed information on how to set up CUBE on the ASR platform for the Box-to-box redundancy option.

Related Information

Level 4
Level 4

I will try option 2 later this week. 

Ah, by the way, I have just received an official response from Cisco: Management interface in ISR4321 CANNOT be used for Checkpointing. So effectively this means that ISR4321 cannot be used as a CUBE with Box-to-Box High-Availability without getting an additional NIM card with some extra ports :)

Level 4
Level 4

I am using the 4331 router for my box-box redundancy.  Your document state to use a switch for the keepalive interface.  is there a big reason for wasting to switch ports?

I am sure there is but could not find any other documents saying so.



Good Day Pamistry

Can you shared some exmaples of configuration (use cases) in a HCS enviroment with  the CUBE or if you have any webcast where we can learn more about CUBE.



Level 1
Level 1

I have used the doc to start my configuration.  I have using ISR4451s, with box-to-box redundancy.  I have configured port channels on the cube,  each interface of the port channel goes to different switches. I have spoken to the BU and they say this will work.  But I am having a link flapping issue on the switches.   Has anybody done this configuration successfully?  We are trying to reach fail over with call preservation.  

Level 4
Level 4

is this happening on both boxes? 

Difan Zhao
Level 5
Level 5

Hi Pamistry,

Thanks for the very clear and easy-to-follow document.

I just have a couple of questions about this box2box redundancy setup with ASR routers, on the redundancy link G0/0/2 for check-pointing traffic.

1. It says that it has to go through a switch. Could you explain briefly why?

2. If it goes through a switch, and when the switch goes down, what will happen to the role and voice traffic?

3. We have all switches in a pair. In that case, should we connect one ASR with sw1 and another with sw2? Sw1 and Sw2 are separate switch, not in stack or VSS setup.



I am creating a network using cisco 4331 router but i cannot find it in cisco packet tracer. Anyone know how to get it? 

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