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Publisher CM / Primary CM!! Confusing

What does Cisco mean by Primary CM, what by Publisher and what's Back-Up CM?

My understanding is that Pub should be the primary, where Sub is the seconday. Where am I going wrong?!

New Member

Re: Publisher CM / Primary CM!! Confusing

There are two seperate relationships.

1- Publisher-->Subscriber. This is based on SQL. The first CM you install at a site will be a publisher. Only the publisher has READ/WRITE access to the SQL database which contains all of the configs for CM. Each additional CM you install will be a subscriber with read only access to database. The Publisher will push the database to the subscriber. Changes cannot be written back to the publisher from the subscriber. Configuration changes can only be made at the publisher.

2- Primary-->Secondary. This is based on what CM the phones register to. When you setup the call manager group, then configure a device pool to use that group you are saying to the phones- "Register with CM1 as your primary call processor, but keep a connection to CM2 in case CM1 goes down." You can have as many as 5 CM in a group, but active connections are only to the first 2. If you have a large install (more than 2 CM) you can create multiple CM groups with different primary and secondary CMs

read this for more explanation-

When I setup a 2 server site this is how I do it-

Server 1

SQL role= Publisher

Services- Backup CM for phones, TFTP, DHCP, Enterprise services, services, any cti applicaitons (ext mobility, ICD, etc...)


SQL role=Subscriber

Services- Primary CM for phones.

I allow the subscriber to do all of the call processing, while the publisher does all of the other little tasks (tftp, services, directories, etc...). I you have more than 2 servers, you can have more division of services.

New Member

Re: Publisher CM / Primary CM!! Confusing

Greg body,

you just gave me the best explanation ever. Now I understand what all this means.

You sure do know your stuff.

God bless and thanks a million.


Afrim S.

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