911 dialing and SRST

Unanswered Question
Mar 26th, 2010

I have a site that is a SRST that is regietered to a Call Manager cluster (7.1.x). When registered to CCM or the 911 calls are going out the local CCM PRI's and not the SRST PRI's.

What can I check to verify why the calls are routing out the CCM PRI's versus the SRST PRI's?

I have this problem too.
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William Bell Fri, 03/26/2010 - 16:02


To answer your question, you need to look at the route patterns, route list, route group, and gateway configurations in CUCM.  Assuming that you have a need to have a different call path for the phones at your WAN/SRST site, you will need to incorporate that requirement in your dial plan.

You have two ways you can deal with this.

Traditional Method:

1.  Create a route group and assign your SRST gateway (if you haven't done this already)

2.  Create a route list for 911 calls (or local or, etc.) and assign the route group from #1 (if you haven't done this already)

3.  Create a partition for PSTN routing for the SRST WAN site (if you haven't done this already)

4.  Create a CSS that phones at the WAN site will use which either includes the PSTN routing partition created above AND your standard PSTN routing partition OR includes the PSTN routing partition above withOUT your standard PSTN routing partition (note, in the former method put your SRST/WAN site PSTN partition in a higher priority position to "override" your default PSTN route partition.  In the latter, make sure you add all route patterns - not just 911)

5.  Assign CSS from #4 to yoru WAN/SRST site phones

6.  Create a 911 route pattern in your WAN/SRST site route partition

Updated Method/Option with 7.1.

1. Same as traditional

2. Create a route list for 911 calls and configure it to use the special route group "Standard Local Route Group"

3. Edit the Device Pool assigned to your SRST/WAN site IP phones and assign the route group created in #1 to the device pool as the Local Route Group.

NOTE:  If you aren't going to use Standard Local Route Group for all IP phones then you will need to add another route group to the route list in item #2 which points to a gateway(s) that make sense in your environment.  OR you can create (or use existing) route groups that are associated to each site and assign them to the appropriate phone device pools.

4. Reset phones in SRST/WAN site

With option 1, you are simply standing up a path using the traditional Route Pattern->Route List->Route Group->Gateway methodology.  With option 2, you are basically telling the CUCM then whenever a route pattern uses the route list created with Option 2, Item 2 - the CUCM should look at the Device pool and use that route group as the primary call path.

You can have other "traditional" route groups in a route list with the Standard Local Route Group.  The Standard Local Route Group can also be in the first, second, third, etc. priority position within the route list.  Think of the Standard Local Route Group as a variable that the CUCM will substitute into the call path selection decision.  Oh, and if a device that does not have a Local Route Group assigned dials a pattern enabled to use Standard Local Route Group, the Standard Local Route Group is just ignored and the next "traditional" route group is used.

Using either of these methods will help you with the issue you are seeing.



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j.sillers Fri, 03/26/2010 - 21:23

(Are you using CER?  If so, you need to say so.  I see it in your tags but that might be errant tagging)


Go to UCM web admin and launch Dialed-Number-Analyzer (DNA).  Choose "Analyze" by Phone.  It is the quickest way.


Don't bother with the "calling" extension, this won't matter, just put in 911 in the dialed digits number then choose the proper CSS from a phone on that site.  Make sure you understand which CSS is allowing the call (Line CSS or Phone CSS)  Usually it is set up so the line CSS would do call blocking/allowing like a class of service (line blocks LD and INTRNL) and the phone CSS would allow you to do anything that has not already been blocked.  Feel free to run the analysis using both to see the difference.

Most places don't use Time of Day PTs so don't worry about the time zone either unless you know some PTs only exist at certain times (If you don't understand this part, you likely are not using it)

The ensuing output will tell you exactly why the call goes out the UCM PRI's  It will tell you which Route Pattern is hit and what Route List that pattern uses (which will include the UCM gateway)

Once you know this, figure out why that pattern is visible to the SRST site's CSS.  Add a new one for that site so 911 calls match it and target the local SRST gateway trunks.

It's hard to advise what to do with the offending pattern since it might be an issue with the local site CSS and not the pattern.  But at the very least re-arrange he PTs in the site CSS so your new pattern exists in a PT that is searched before the offending PT.

(If you are using CER then DON"T ADD ANY NEW PATTERNS.  re-post your question with the DNA output.  Likely the calls are going the wrong way due to the wrong E911 pattern being in the wrong CSS for this site)

Message was edited by: JOSHUA SILLERS


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