SRST using HSRP

[CiscoRunner]

Is SRST supported using the HSRP address between dual voice gateways?

I have seen some reports that it is not TAC supported and not possible in IOS v15 and above. IF this is true, what is the design recomendations for voice with dual voice gateways at a critical site?

[Chris Deren]

I have never done it, but don't see why it would not work.  If you find it does not work, one way is to split the SRST reference between the 2 GWs and then build voip dial-peers pointing to each other for proper trunk redundancy.

HTH,

Chris

[islam.kamal]

Hello

+5 of course for MR/Chris.If we have a site with 200 IP phones , with two Gws A&B. Please advise for the below steps:-

1-Create 2X DP ( DPA & DPB ) , where DP "device pool".On DPA i will use GWA as SRST gateway and on DPB i will use GWB as SRST GW.The Problem on SRST the phones uses SRST reference IP address to reregister if the CUCM id down. On HSRP technology , the virtula IP which includes (2 X GWs) will never work and IP phones will not reregister. .

Thank you

please rate all useful infomration

[Jorge Armijo]

HSRP + SRST is not a supported solution, you may want to explore a different way.

--
Jorge Armijo

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[Jonathan Schulenberg]

Sorry Jorge, I have to disagree with you here. HSRP has been used with SRST/CME failover in past designs, including even a Cisco Validated Design. This can work but the PSTN-facing circuits failover gets tricky. If you have analog you can just put both routers on the loop and use ground-start. If you have a digital circuit you either need a mechanical switch box, manually move the cables, or have double circuits with carrier-assisted failover routing.

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[Jorge Armijo · Accepted solution]

I understand what you're saing Jonathan, I know this setup have been discussed a lot over the past few years, in fact I worked on a couple of issues realted to this, somethimes it worked, sometimes it didn't.

I just wanted to give a heads up about it, after looking on some documentation, I couldn't find anything related on official documentation on how it is configured. The link you're mentioning is CME, not SRST, and even if both are similar, they behave differently depending of the configuration.

I read the document you posted, and found this note:

"Performance Test Cases

Note All  voice only testing configurations used the Cisco IOS service provider  image 12.3(11)T6. Any performance data and device compatibility derived  from this testing is not valid with any other Cisco IOS software image."

So, the fact that HSRP was tested with CME just tell us it worked with that specific IOS image, but as I mentioned I couln't find any related configuration example on CCO, and it makes me doubt of the setup.

Here's the SRST feature Roadmap:

http://www.cisco.com/en/US/docs/voice_ip_comm/cusrst/admin/sccp_sip_srst/configuration/guide/srst_roadmap.html

Cisco Unified Survivable Remote Site Telephony (SRST) and Cisco Unified Enhanced SRST (E SRST)

http://www.cisco.com/en/US/prod/collateral/voicesw/ps6788/vcallcon/ps2169/prod_qas0900aecd8028d113.html

Configuring a Secure Survivable Remote Site Telephony (SRST) Reference

http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/security/4_1_2/secusrst.html

Configuring SRST Fallback Mode

http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/admin/configuration/guide/cmesrst.html

Cisco Best Practices Survivable Remote Site Telephony Design Guide
http://www.cisco.com/web/about/ciscoitatwork/downloads/ciscoitatwork/pdf/Cisco_IT_Case_Study_SRST_Design_Guide.pdf

I have also found 2 enhancements to support SRST+HSRP:

CSCtx42326 = Port 2000 of HSRP IP add gets blocked on reload of Router using SRST

CSCtz96320 = SRST fallback Fails with HSRP

That's just my feedback based on previous experience.

Good day to all of you!

--
Jorge Armijo

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Performance Test Cases