Question about e.164 Dial Plan

[cgmiller913]

Hello,

I have a question about e.164 dial plans. I've done a bunch of searching but haven't quite found the answer.How do you get around non-did extensions. For example i have courtesy phones, logged out hotelling phones, unity connection pilot etc. Is it acceptable in an e.164 dial plan to have 4 digit extensions (or i guess non\+ extension) for phones without DIDs?

Thank you in advance.

[Chris Deren · Accepted solution]

Technically you can have variable length extensions on the cluster, but recommend sticking with +e164 for everything including non DIDs.  What I do for non-DIDs is create a range that would never exist for that country, so for example for North America dial plan I usually use +1000XXXXXXX as there never will be area code 000.

[cgmiller913]

Awesome. Thank you so much for the reply.

One other question, to avoid 4 digit overlaps on translation patterns, i'm guessing it's best to segment the translation pattern partitions by area code/country code? NY Offices have access to NY xlate patterns, CA offices have access to CA xlate patterns, UK etc etc and then do site to site access codes?

Again, thanks for the quick reply.

[Chris Deren]

Correct, if you decide to use translation patterns for abbreviated dialing then they have to built in proper partitions to avoid any potential for overlaps. This can be done per site, per county, or whatever the breakdown is.

[Roger Kallberg · Accepted solution]

The approach we used for non DIDs in our global deployment with 160+ sites in more countries than I care to count is to format them as \+0 <country code> <area code> <subscriber number> as there will never be any real country code that start with a 0 (zero). For short abbreviated dialing we build them as this <country code> <site code> <last 4 digits of the DN>.

To give an example for a site with made up numbers.

DID range +464055XXXX

DN +4640556677 abbreviated number 4616677

Non DID range

DID range +0464055XXXX

DN +04640558877 abbreviated number 4618877

Our abbreviated dialing is visible in the entire system, so we make sure to keep these from overlapping.

[cgmiller913]

Thank you both. Clears things up for me. 

Happy Holidays!

Cheers.

[Anthony Holloway]

There has been a change to that recommendation to use fake +E164 numbers, which is to come up with a new format, usually, but not required, in the 8 + 3 + 4 format. The benefit is to gain a dialing habit for free, by using a numbering plan which aligns with your dial plan.

The antithesis would be using a numbering plan, which no one will ever dial, therefore, it serves very little purpose or benefit. If that's not immediately obvious and understood, just imagine if I prefixed all of my DNs with *#*001*#*. Then you come along and ask: "Do your users have to dial that?" I respond with: "No! I created translation patterns which prefix that for the users, so no one ever needs to dial that crazy prefix." Then you ask: "So, what's the point of putting that prefix on all the DNs then?"

Though, I fully admit, that a recommendation is just that: a recommendation, and it's not the law of the land. I just thought I'd mention it, since the fake +e164 recommendation has been revoked by the same person who published it: Johannes Krohn.

You can read more about the recommendation for Non-DID here:
https://www.cisco.com/c/en/us/td/docs/solutions/CVD/Collaboration/enterprise/12x/120/collbcvd/control.html#pgfId-1074143