Partitions and Calling Search Spaces

[Nightwolf_82]

Hi guys,

I would highly appreciate of you could clarify some nuances about Partitions and CSSs. Even though I watched and read about it I still can't understand the way it works. For example, I created 3 Route Patterns, 5 Partitions and 4 CSSs (pls see screenshot ptcss0). On Screenshot ptcss4 for 2482 device I specified CSS SYD-Unlimited-CSS, which implies that a user can make unrestricted direction calls from this phone because SYD-Unlimited-CSS includes all 5 Partitions. This is clear. The thing I can't understand is why all that don't work until I assign Partition for DN 2482? 

In my case I couldn't understand why 2483 being assigned Partition "NONE" and CSS "NONE" still can call on 2482. After I specified Partition for DN 2482 calls from 2843 to 2842 started to be blocked. As I understand it is mandatory to specify Partition for DN. Then the question is which of 5 Partitions I should specify for every specific DN? 

Thank you.

[Jaime Valencia]

Because the <none> partitions is always included in every CSS you create, even if you don't see it listed, that will be the last partition in the CSS.

The SRND covers the topic of CSS and partitions thoroughly and provides plenty of examples and diagrams about this.

Simply put, the CSS defines who you can call.

The partition will group DNs as per some characteristic.

If you google "cisco css and partitions" you can find a lot of videos and pages that also explain this.

[Nightwolf_82]

Hi guys,

Here is my scheme 2XXX - CUCM - VG - WAN - CME - 5XXX. Now that, when I configured all Route Partitions, Partitions and CSSs, why the call flows from 2XXX to 5XXX work fine but don't vice versa? When I specify NON Partition for 2XXX phones, call flows from 5XXX to 2XXX work perfect.

What should I configure in order to have calls from 5XXX to 2XXX work as intended. 

Thank you.

[Suresh Hudda · Accepted solution]

How you integrated cucm and cme ? Is it on sip trunk ? If yes, then in cucm go to sip trunk page and scroll down the page till Inbound section, there you need to specify CSS that having partition which is assigned to 2xxx.

Suresh

[Nightwolf_82]

Hi Suresh,

Thanks for your help. It works now. One question in this regards. Should I specify the least restrictive CSS that comprises as much as possible Partitions on SIP trunk? 

Thank you.

[Suresh Hudda]

This CSS on sip trunk is only for inbound calls so you need to assign only those partitions which are assigned to directory numbers (phone' line, cti route point) and translation patterns etc. In other words where (phone, translation pattern, hunt group, TOD etc) you want to land incoming calls which comes via sip trunk, those' partitions should be on that CSS which is assigned on sip trunk.

Suresh