Cisco CME to centralized UCM

[GWaldbin]

Hello,

we will be converting a remote site currently running it's own CME to a centralized servers running UCM. The plan is to deploy a Cisco 2921 voice router with SRST and move everything over. I am looking for any documents which can help me to figure out if I would need to buy different licences, what else I would need to consider for this change etc. If anyone can guide me to right documents that would be very helpful. Thanks

[Manish Gogna · Accepted solution]

Hi,

First, you need to have sufficient licenses on cucm to allow for the IP phone registration from the remote site. The SRST license needs to be present on the gateway for srst to function. CME/SRST licensing is explained very well here

https://supportforums.cisco.com/document/111386/understanding-cme-srst-license-activation

Then you can add this gateway as SRST on cucm admin page as explained below

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/8_5_1/ccmcfg/bccm-851-cm/b02srst.html

Gateway will need to be configured for SRST as well.

Manish

[GWaldbin]

Thank you Manish...I will try this out

[GWaldbin]

sorry to ask you again---I am still preparing for this conversion and have few more questions to ask

in my post I didn't mention that currently this site has 3 digit dialing. Of course, after converting to central UCM, they will have 4 digit dialing (typical). Also, we want to use existing phones with the new deployment because they all are 7942s and 7925s. My question is-how can I have all the existing converted to new CallManager without haveving long disruptions with the phone services?

Do I need to delete the trust-list on the phones first? OR just need to reboot them and they will register to new callmanager on central site? Thanks

[Manish Gogna · Accepted solution]

Hi Gerome,

Since the migration is from CME to CUCM there is no way or exporting cme config to cucm. You will need to assign the 4 digit extensions manually to the IP phones when they register with cucm. In case of auto registration enabled cucm they will get the auto configured DN's without you having to do it manually. Then you may use the Bulk Administration tool on cucm if you want the extensions to be a particular range. if there is no existing CTL/ITL file on the IP phones then they will register automatically with cucm when pointed to tftp server ( with auto reg enabled cucm cluster ) , in case of auto reg disabled cluster you can add the phones manually on cucm using their mac address and they should register just fine if there is no existing itl/ctl file on them. If any itl/ctl files exist then you need to delete them first.

Manish

[GWaldbin]

Thank you very much Manish....I will give this a try

[GWaldbin]

Hello Manish, wondering if you can answer one more question on the same subject---currently this remote site has only one PRI and CME. When I deploy my new voice router, obviously, I can't have option 150 on both routers on same vlan (voice)!!! How can I test if everything working without taking the current phone system down for long time?

My plan is to take the 2nd set of phones, configure them on centralized CCM prior to plug them in to the switches. Can I manually assign the tftp server IPs on the new phones and it would work? Thanks

[Ayodeji Okanlawon]

You can use alternate tftp on selected phones registered to ccme to test your setup..

Here is a link to how to enable alternate tftp on the phones..

The alternate  tftp ip will be your cucm tftp ip address

h

ttp://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cuipph/7905g_7912g/5_0/sip/english/administration/guide/5_0/LowPset.html#wp1264765

[GWaldbin]

thanks for the info---

so you are saying I can have 2 voice routers on same vlan with option 150 and this setup would not create any issues as far as I have alternate tftp setup manually on the new test phones?

If a phone on CME gets reset for some reason, how does it knows where to find the info it needs for setup?

[Ayodeji Okanlawon]

Yes it wont create any issues. The test phones will register with the CUCM and not the CCME. When the phones are reset as long as the alternate etftp is present it will always use that for its configuration download. When you are done testing you will need to remove the alternate tftp so the phone can use its local option 150 and register back to CCME. But you will need to delete the "ITL" file on the phones for them to successfully register back to the CCME

[GWaldbin]

good to know... many thanks

[Rafael Jimenez]

You can move the old cme config to the new 2921 and use it as gateway for the new CUCM as well. Just add and setup your new CUCM with the same configuration for phones, lines, route patterns.
Setup the SRST reference in the CUCM. Just leave the cme in the 2921 as the backup for the cucm. You don't need change to SRST.