Single-server CCM ?

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Apr 11th, 2007
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Hello,


I wanted to ask if anybody has experience in installing CCM without clustering, that is a single server possibly backed-up by a router is SRTS. I would be interested in doing that with 5.x / 6.x


Thanks!

Correct Answer by thisisshanky about 10 years 1 month ago

Paolo,


In traditional SRST mode, the amount of features you can implement are limited. If you want huntgroups, call park, pickup groups, BACD queueing etc, SRST has limited capability to do all these functions. (There are workarounds to create a basic huntgroup using alias commands in traditional SRST). With CME 4.0, Cisco introduced CME with SRST fallback support. THis requires that you buy SRST feature set licenses for the router. Instead of "call-manager-fallback" command, you can use the "telephony-service" command like in CME. You will configure a command called srst auto-provision to automatically allocate ephone-dn's when each phone register with the router. In Callmanager you would create an SRST preference for the phones and tell it to register to the CME router's ip address. Check this link for more details.


http://www.cisco.com/en/US/products/sw/voicesw/ps4625/products_configuration_guide_chapter09186a00807e0566.html


After configuring the router as per this link, perform a failover from Callmanager to the CME router and all the phones will register with the CME router. Phones will keep their original DN's that are configured in Callmanager. Once the ephone-dns/ephones get generated in the config, you can set up any CME like feature you want.


HTH


Sankar.

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Brandon Buffin Wed, 04/11/2007 - 05:37
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This is certainly technically feasible, but not a recommended practice. With only one Callmanager, you have no redundancy for call processing, TFTP, MOH, CTI, etc. This redundancy comes into play in the case of a server or service failure as well as during maintenance/upgrades allowing these issues/activities to be transparent to users. You could use SRST as a backup, but this would be more of a disruption to users as SRST contains a subset of CCM features and is really meant for temporary WAN outage scenarios at a remote site. You may also run into scalability issues with SRST. You can support up to 720 phones with a 3845, but depending on your needs, it might make more sense to put those dollars towards a subscriber server(s).


Brandon

thisisshanky Wed, 04/11/2007 - 06:05
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YOu may also run the SRST router in CME mode with SRST fallback. This will give more CME like features for phones, when Callmanager fails.

paolo bevilacqua Wed, 04/11/2007 - 06:55
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Hi Shanky, can you expand on this ? What would be the difference compared to "normal SRST mode" ?

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thisisshanky Wed, 04/11/2007 - 07:42
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Paolo,


In traditional SRST mode, the amount of features you can implement are limited. If you want huntgroups, call park, pickup groups, BACD queueing etc, SRST has limited capability to do all these functions. (There are workarounds to create a basic huntgroup using alias commands in traditional SRST). With CME 4.0, Cisco introduced CME with SRST fallback support. THis requires that you buy SRST feature set licenses for the router. Instead of "call-manager-fallback" command, you can use the "telephony-service" command like in CME. You will configure a command called srst auto-provision to automatically allocate ephone-dn's when each phone register with the router. In Callmanager you would create an SRST preference for the phones and tell it to register to the CME router's ip address. Check this link for more details.


http://www.cisco.com/en/US/products/sw/voicesw/ps4625/products_configuration_guide_chapter09186a00807e0566.html


After configuring the router as per this link, perform a failover from Callmanager to the CME router and all the phones will register with the CME router. Phones will keep their original DN's that are configured in Callmanager. Once the ephone-dns/ephones get generated in the config, you can set up any CME like feature you want.


HTH


Sankar.

Rob Huffman Wed, 04/11/2007 - 08:03
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Shanky,


This is some really excellent information! Thanks, as always. 5 points for sure.


Take care,

Rob

paolo bevilacqua Wed, 04/11/2007 - 08:57
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Absolutely essential info, rating "5" is the less I can do.

thisisshanky Wed, 04/11/2007 - 09:04
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Rob and Paolo,


Thank you very much for the 5's.


I have had nothing but good experience with implementing CME in SRST mode. Especially for implementations where you have a call center with IPCC/CM, when callmanager fails, you can rely on basic hunt groups with queueing from BACD to simulate a mini-call center.


Sankar.

paolo bevilacqua Wed, 04/11/2007 - 09:13
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This is *so right* on the spot Shanky, that at the cost of looking flattering, I have rated you again!

thisisshanky Wed, 04/11/2007 - 09:25
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i am totally flattered. Thanks again!!

boonwah-tay Thu, 05/31/2007 - 20:36
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The SRST Fallback Support for CME is a extremely good feature. However, in this case, in SRST fallback support mode, CME can support only up to 240 phones. Where as SRST can support up to 720 phones. How can we then achieve CME SRST Fallback Support with up to 720 Phones?

mchandak Wed, 04/11/2007 - 06:05
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I do this all the time in my Lab. I use a standalone Publisher and have all the services activated on this server. It should be pretty straight forward. It had worked great for me all this while and did not face any issue. If there is something specific you are looking for, let me know

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