Utilizing the Standard Local Route Group with CER

Question

Hello,
I'm running UCM 7.1(2) and recently a contractor we brought in to install our CER 7.0(1) created a very signicicant amount of Calling Search Spaces, Route Patterns, Partitions, Route Lists and Route Groups in an effort to route calls from our 6 sites (we are centrilized with one Publisher and 6 suscribers) out the correct gateway towards the correct PSAP.
I took the contractor's word that we needed to make such drastic additions and now I belive I made the wrong choice. We already have a Route List (PSTN_RL) that includes:
1)Standard Local Route Group
2) XX_RG (the backup RG)
3) XX_RG (another backup RG)
Most of my Directory Numbers (DN) and the Primary CER Route Point belong to one Partition (PhoneLines_PT) and I would like all the calls from the Directory Numbers associated with the PhoneLines_PT to be routed via the Route List that utilizes the Standard Local Route Group (PSTN_RL) and maintain that CER is able to "see" 911 calls.
Can anyone tell me if I I change the PSTN_RL (Standard Local RG) associated Route Pattern Partitions to the PhoneLines_PT, will all Directory Numbers associated with the PhoneLines_PT route calls over the PSTN_RL?
I guess I am trying to wrap a sort of reverse implementation "around my head."
Thanks in advance for you time.

Answer 1

Partition and Calling Search Space (CSS) are closely related but always confused.
Good examples are:
Line A and Line B in the same partition doesn't necessarily mean Line A can call Line B.
Phone A and Phone B have the same CSS doesn't necessarily mean Phone A can call Phone B.
Now back to the topic of LRG (Local Route Group).  A good use case would be 911 calls.  We always want 911 calls to be routed through local gateway so it can reach local PSAP.  Without LRG, you'll have to configure multiple 911 patterns (in different partitions) so you can assoicate them with different gateways.  With LRG, you just need one 911 route pattern.  Of couse that route pattern should be accessible by everyone.  To make it simple, you may put it in null partition.
Michael
http://htluo.blogspot.com