Call Manager - questions

[kunal-united]

Hi,

Scenario: all the phones are registered thru the call manager and they download the configuration from tftp server.

Question1): when the call manager is disconnected then no new ip phones will get registered ...Is this true?

Question2): If the call manager is disconnected, phones which have downloaded the configuration will work until they are powered off...Is this true?

Question3)

where does the minutes of the call get tracked? Who keeps track? is it the Call Manager?

how do you know which phone called which phone? Who keeps track? is it the Call Manager?

Please provide references.

Thanks

[Chris Deren · Accepted solution]

How many CUCM servers do you have in your cluster?

Is CUCM server providing DHCP?

If all CUCM servers are unavailable no phones will work does not matter if they have configuration file or not. Before phone can register and download the file it needs to obtain IP address either from DHCP or statically defined, if DHCP server goes down, the phones will keep the IP address until they need to renew it, typically this is half way through the DHCP lease, so if your DHCP lease is 30 days, phones will renew the lease on the 15th day.

Please let us know if this is what you are looking for.

HTH,

Chris

[kunal-united]

Just 1 Call Manager.

CUCM is not the DHCP server.

Why will no phones work if there is no Call Manager? Please provide reference.

Question3)

where does the minutes of the call get tracked? Who keeps track? is it the Call Manager?

how do you know which phone called which phone? Who keeps track? is it the Call Manager?

Thanks

[Chris Deren · Accepted solution]

Why will no phones work if there is no Call Manager? Please provide reference.

Becuase phones are dummy terminals, they need call processor to tell them what to do, CallManager or CallManager Express can be a processor.  You should never design a system with no redundancy, if you cannot add another server add SRST gateway for failover.  Take a look at Cisco Communications Manager SRND document for detailed explanation on how it all operates:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_implementation_design_guides_list.html

Question3)

where does the minutes of the call get tracked? Who keeps track? is it the Call Manager?

how do you know which phone called which phone? Who keeps track? is it the Call Manager?

What do you mean "minutes", do you mean detailed call records (CDR)?  If so yes CallManager tracks all CDR records in CDR database, CallManager comes with CMR tool for accessing the records and running reports, but it is not very good, so a lot of customers get 3rd party call accounting applications.

HTH,

Chris