dial plan design

[lorenz84gDD]

Hello all,

someone can help in: how to design a dial plan?

I have three main blocks: Corporate site, HQs and boats.

1 corporate

4 hq

100+ boats

I want to use this kind of dial-plan:

8 XX Y ZZZZZ

where:

8 voip code

XX country code: 49 germany

Y corporate (7), hq (6) and boats (5)

7 ZZZZZ

6 [II]ZZZ

5 [JJJ]ZZ (*)

I was wondering if this is the correct way of designing a dialplan.

And more: what if I have in (*) ZZ=88 and a country code starting with 8? I think I would have an overlap between  881...... and the extension 88, is it correct? I would allow intrasite calls with two digits. So inside a boat I would be able to call another user with 88.

I went through the srnd but it's not very clear about this point. do you have some links/books to understand better the dialplan design topic?

Some help on this would also be apreciated.

thanks for your help

lorenz

[Jaime Valencia]

That looks good, if there are chances you might grow beyond the actual number of options for XX or Y, increase the number of digits to allow for future growth.

Assuming they will be able to dial only a certain number of digits for direct calls between their own branch, and that overlaps with 8 XX Y, you'll have to wait for IDT,  or explain they need to press #

Ideally you would use the 8 for nothing else than the VoIP code so this doesn't happen.

Your other option would be to go right now with a E.164 dial plan and that would avoid any kind of overlapping, then just have them do X number of digits for local/site calls and dial E.164 for any other call.

Assuming you also want to do TEHO, that would be the way to go.

HTH

java

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[lorenz84gDD]

No short extensions starting with 8 are supported without triggering the interdigit timeout, right?

88 would become with a translation pattern: 8 8X Y WWW88 but will trigger i.d.t ?

What do you think about the sub-prefix (jjj) inside this:

5 [JJJ]ZZ

I would distinguish a boat in site 111 and a boat in site 112 so:

5 11100 and 511200

Is it right?

thanks

lorenz    

[Gert Vanderstraeten]

Lorenz,

We designed the 8-digit dialplan inside Cisco in 1999 when E.164 format was far from available on our systems. As Jaime mentioned already there are a lot of advantage of using E.164, and it's your best way forward.

On your questions, keep in mind that you probably want a unique extension of a fixed lenght on every phone - which is independent from the number dialed within a site. If your extension numbers are overlapping with your inter-site prefix - 8 is what we are looking at in this example - you shift your internal extension dialing to the left with one digit. Eg. if your internal extension starts with 8XXX and the last 5 digits of your PSTN number is 68XXX you use that for intra-site calling. That way you don't run into i.d.t. issues.

If your PSTN numbers end on 88XXX you still have a problem - you can or ask your PSTN provider for another range (which is what we did within Cisco for a couple of offices) or you can ask your users to use an intra-site prefix 5 plus the last 4 digits of their extension. But it breaks your consistency across other sites, and is a bad idea IMHO.

If you want to use 2 digits intra-site dialing, keep in mind that you will run out pretty fast (you also need unique numbers for non dialable numbers like voicemail ports, ivr ports, call park, meet me numbers etc). For larger sites I guess you need more digits for sure.

Gert

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