Cisco Unified Border Element (CUBE) High Availability on ASR Platform Application Note

[pamistry]

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

• CUBE High Availability(HA) Configuration on ISR-G2
  
• FAQ: Cisco Unified Border Element
  

[Mavinktul]

Hi Pamistry,

Great document....Do you have any document/config guide for support for Media Resources specilly MTP on ASR 1k series. There seem to be very few docs on this.

I am trying to search for info where it explains on HA CUBE  if one is active and other is standby
how will the media resources work

Thanks

[jefflocktsg]

Great write up. Is this basically the same procedure for doing box-to-box redundancy on the Cisco 4431 IOSXE with CUBE HA? I know we have to use RG Infrastructure and not HSRP on the IOSXE platform. Also, can this be done with sub-interfaces in the event that my CUBE HA need to support multiple SIP ITSPs?

Thanks

[dshekarb]

Hi Pamistry,

Nice doc. But do you have documentation for ASR1006 cube HA config.

[tdudas]

Hi,

I think I need the same solution, would like to have two virtual IPs on the WAN side (ISR 4331), and I suppose sub-interface would be needed, but I'm concerned if it is possible at all? Unfortunately I do not have the box to give a try and play...

Did you manage to find this out?

Many thanks,

Tibor

[tdudas]

Hi Pamistry,

Very useful doc! Many thanks for creating!

I would like to know, if more than one Virtual IP address can be configured for the WAN side? I suppose, this might be done with subinterface, but I concerned if possible at all.

Do you have experience on it?

Many thanks,

Tibor

[davethehedgehog]

Hey there, did you find out, is this procedure basically the same as the 4000 series? I believe it is, but I was interested if anyone had confirmation. The docs on CUBE HA using IOSXE are rubbish!

[Marcel Imrich]

Sure Dave,

it is fully functional even for ISR 4000 platform (for example ISR 4331) or CSR1000v in VMware. For complete HA functionality you'll need AX license (bfd etc.).

Marcel

[tdudas]

Hi Marcel,

Did you manage to configure also two Virtual IP on the WAN side? This is what you are referring to as fully functional?

Many thanks,

Tibor

[Marcel Imrich]

Hi Tibor,

I was just referring to ISR 4000 config. and this is pretty the same as for ASR platform. As for the subinterface configuration for HA, it looks like a working scenario but I didn't have time to test it. I'll build small lab on CSR 1000v and let you know.

Just one comment, I don't think so this would work for sip trunk registration. In case of CUBE HA it have to be done in global "voice service vip" section so you have to specify just one physical interface (eg. GigabitEthernet1.100 in case of subinterface config) otherwise the register SIP message (actual packet) comes from physical not virtual IP address. By my experience this won't be accepted as correct registration message from ITSP side (Oracle SBC is one of them).

Definitely worth a try ;)

Marcel

[davethehedgehog]

Hmmm, hold on a second. So back in 2900 days you'd buy your router, your UC license and your RED CUBE licenses.

So what you're saying is in the 4000 world you have to buy the router, the UC license the RED CUBE licenses and an AX license? Is that the case?

[Marcel Imrich]

Not necessary,

as the concept will work without the "bfd interval" configured under the rii interface. So this is just one small detail I run into lately. Maybe someone could explain me the difference (there is nothing like this in Cisco docs for CUBE HA).

Marcel

[dshumake]

Great document..

Using the 4k in box2box redundancy configuration.  I will need some transcode and mtp's configured on each box.  what would be the best practice for setting this up?

thanks..

[Marcel Imrich]

Hi,

it depends how critical it is for you. There are two possible scenarios, DSP resources active on both routers and active/standby scenario leveraging RG infrastructure config on inside interfaces.

With the first option you'll have to bind the sccp to preconfigured loopback interface and use it as a source IP address for HW MTP, transcoding resources in UCM.

Second option is little bit easier as you will have just one CUBE with DSP resources active in a time. Standby CUBE won't register as the bind interface (Virtual IP) is not active. In case of failover, it will immediately register to UCM using the same IP address. Anyway you'll have to configure both of them as the identifier is different.

Marcel

[Alexander.Khlemanov_2]

Hi Marcel,

Do you know if this procedure is also working for ISR 4321? In 4321 there are 2 customer interfaces (Gig0/0/0 and Gig0/0/1 which are both in use) and a Management interface with vrf permanently attached to it. Is it possible to use the Management interface for Checkpointing? I have configured it but my peers do not see each other though you can ping the IP addresses on the Management interfaces from both peers. Also for some reason there is no "bfd" command in the interface configuration mode. Is this command a "must" for Box-to-Box HA?

Regards,

Alex.

[tdudas]

Hi Marcel,

Many thanks for your reply!

Did you have a chance to give a try in your lab?

Regards,

Tibor