Setting up SRST as backup for CUCM on singlesite deployment

[Vigeesh Mohandas]

Hi,

WE are going to setup CUCM 8.5 on UCS210 c series server. single ucs so only one publisher which run on esxi4.1 vmware instand.

As there is no subscriber for backing up ip phone sevice when CUCM is down we had planned for SRST on same site on 3945 router.

router details

C3945-VSEC/K9 *2

S39UK9-15104M * 2

FL-SRST *2

FL-CME-SRST-100 *12=1200

FL-CME-SRST-25 *2=50

NM-HDV2-2T1/E1 *2

PVDM3-64 * 2

so what my question is

1. what is the max Ephone / Dns on one router i can give

2. Best practice tips

3. IF any documments on this please share

4. your advice and recommentation on this type of setup

Please reply urgent.

[Chris Deren · Accepted solution]

Since you have UCS server why are you not installing another VM with subscriber? Do you not have any remaining resources? 

3945 can provide you with 1200 SRST licenses:

http://www.cisco.com/en/US/partner/prod/collateral/routers/ps10536/data_sheet_c78_553924.html

if you need that many phones I strongly suggest you deploy at lest 1 subscriber.

HTH,

Chris

[Vigeesh Mohandas]

Thanks for reply,

Yes you are right but even if installing Subscriber on same UCS it will be single point of failure. if that UCS is down entire setup is down.

thats why we plan for this type of setup with SRST on two 3945 router.

we had already gone through that data sheet but I'm confused; in that total phones supported is 1200.

In our setup we have 625 license for one router, so in this case

what will be the ---  MAX Ephone   and   Max Dns that we can configure.

I our setup each router is having extra one PVDM2-64, suppose if CUCM is down how the router utilised PVDM.

As DSPFARM will not work when CUCM is down.so how the  MTP,conferencing and transcoding treated.

waiting for your reply

Thanks in advance

Vigeesh Kalathil

[Chris Deren · Accepted solution]

Yes you are right but even if installing Subscriber on same UCS it will  be single point of failure. if that UCS is down entire setup is down.

Correct, I would still take this over SRST though, how big is your deployment, was there no funds for second UCS server?

Perhaps look into CME as SRST option to get some more capabilities out of the router, but this decreases the max ephone limits.

In our setup we have 625 license for one router, so in this case

what will be the ---  MAX Ephone   and   Max Dns that we can configure

625 max ephone's as that is all you are legally licensed for, the 1200 is an upper limit.  Keep in mind the licenses are right to use and are not enforced. ephon-dns are not licensed.

HTH, please rate all useful posts!

Chris

[Vigeesh Mohandas]

Yes you are right.As if now we are planning for 650 user's on cucm. only part of our facility is ready now and will expand in near future that time we will propose our management as per your suggestion.

How to configure CME as SRST ?

command's for this ?

if using CME as SRST ; number of ip phone used will reduse to 350 right ?

if you have any configuration document please share it.

thanks

vigeesh kalathil

[Chris Deren · Accepted solution]

Check out this admin guide for details:

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

HTH, please rate all useful posts!

Chris

[Vigeesh Mohandas]

suppose if number of ip phone supported is 350. in that case dose the cisco ip phone 7962G and 7911G are  treated as same ? or any dependency based phone line on the ip phone?

thanks

vigeesh kalathil

[Chris Deren · Accepted solution]

Yes, all phones are treated the same, but you can control which phones are going to register with SRST via CUCM configuration, so you can exclude some phones from it.

HTH,

Chris

[Vigeesh Mohandas]

Ya it's the only option to control the phone registration on srst mode.

Other query is that PVDM2-64 which we had used for DSPFARM on CUCM (transcoding, conference,mtp) will the router use that resource on SRST mode.

Thanks for your support.

Vigeesh kalathil

[Vipul Jindal]

no for that u have to configured them as a resouce in SRST as well!!

you can add the SRST ip source addres to SCCP identifier command  and give it last priority!!

thanks,

Vipul JIndal