I am in the process of setting a corporate standard for how phones are configured in our CallManager server. We are currently running 4.2(3) but are looking towards 6.1 in the future.
Part of this process is laying out the best way to configure a phone for ease of administration, security, and functionality. There is one place I've gotten stuck and that's the phone Calling Search Space (CSS). I have read both a Cisco IP Telephony and CallManager Best Practices book and done many searches and I seem to get conflicting information.
We are currently setup in a centralized model and only allow inter-site dialing through access codes. According to the Best Practices book, we are currently using one of the worst approaches for number of partitions and css's but the best practice approach doesn't really work because of the need to keep the phones isolated.
From what I can tell, the best option would be to create 5 main partitions and any others that are required by site. (Phones, Emergency, Local, Local and Long Distance, and International.) I would then create matching CSS's for security. (Internal, Local, Local & Long, International.) I have that developed so far but how do I actually use those correctly on the phones? I was under the assumption that the phone used the Line CSS for Call Forward settings if they were not defined but I found that isn't the case moving forward. With that in mind, the proper CSS's should be defined for Call Forward settings as well.
Now, we are at the phone configuration phase, there are two places to define the CSS, the device and the line. From what I've read, there really isn't a need to use the two concatenated together. Would it be better to use the Device level and leave the line at none or set the device to none and use the line level?
have you gone thru the SRND?
That topic is throughly covered there:
Calling Privileges in Cisco Unified CallManager
Building Classes of Service for Cisco Unified CallManager
Classes of Service with the Line/Device Approach
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