Multiple dial-peers for a single voice-port

[jaimeatnok]

I know that you can configure multiple dial-peers for a single voice-port but it seems I'm not able to achieve the functionality I'm looking for.

We've got an E1 (primary rate - 30 channels) for connectivity to the PSTN which serves 100 MSNs, from "700" to "799".

What I'm looking to achieve is the selective routing of some MSNs to IP phones within a certain extension range and others to IP phones within another extension range.

For example, I want MSNs 713,751,776 to be translated to IP phones 813,851 and 876 respectively. The remaining MSNs are to be translated to IP phones in the 6xx range.

I've created two dial-peers for the same voice-port, each with a different "translation-profile" which aims to achieve the above but alas its not working...it always matches dial-peer 30:

dial-peer voice 28 pots

description INCOMING_DDI_8

translation-profile incoming incoming-did-8

preference 1

incoming called-number 7[0-9][0-9]

direct-inward-dial

port 0/2/1:15

!

dial-peer voice 30 pots

description INCOMING_LEG_DIALIN_6

translation-profile incoming incoming-did-6

preference 2

incoming called-number 7[0-9][0-9]

direct-inward-dial

port 0/2/1:15

!

[paolo bevilacqua]

In you example, 30 is matched all the time because it has higher precedence and identical incoming called-number as 30.

But, how many translations do you need ? If less than 15 you can fit them all under a single voice translation-rule. And if you can work by patterns, even less rules will be necessary.

Note: you don't need to configure port for incoming DP. The port statement is ignore as you will see trying a wrong port or none at all.

[jaimeatnok]

Unfortunately more than 15 or else a single translation-profile would be enough: 14 individual rules + 1 general rule for the remaining MSNs.

I thought DP 28 had a higher precedence than DP 30...hmmm, in fact does this means that a DP with a higher number has a higher precedence?

[paolo bevilacqua]

Ok for the rules, anyway from you previous example, it seemed that some rule can be grouped in patterns.

Tag ID of the DP has no significance in precedence: if you want them to match correctly called number, configure appropriately as "incoming called-number".

as a recognition to those providing answers, please rate useful posts using the scrollbox below!

[jaimeatnok]

Ok, thanks :)

But how can DP 28 be given a higher precedence than DP 30?

As you can see I'm using the "preference" command but I don't think its having any effect.

[jaimeatnok]

I've swapped both dial-peers to obtain the functionality I need but I'm still clueless as to why one has a higher precedence than another even though I've got the "priority" command set.

[paolo bevilacqua]

Hi,

I may need to correct my previous statement about preference because as in your case, the truth could be that the preference statement is ignored on incoming DP so the "winner" is selected unpredictably.

If it is like that it would still make sense because these are incoming DP and would not make sense to have a "preference" in presence of identical "incoming called-number" like you had.

Instead for outgoing DP that can have up/down state, different routing, etc, it makes sense that the preference works as configured.

[bgibson]

Well one thing you could do is...

dial-peer voice 28 pots

description INCOMING_DDI_8

translation-profile incoming incoming-did-8

preference 1

incoming called-number 7..

direct-inward-dial

port 0/2/1:15

dial-peer voice 28 pots

description INCOMING_DDI_8

translation-profile incoming incoming-did-6

preference 1

incoming called-number 751

direct-inward-dial

port 0/2/1:15

By doing this you would have a catch-all to match your primary translation profile and then specific route patterns for excess numbers that couldn't fit in your translation list.

You really want to try and avoid using multiple exact match dial-peers unless you have a really good reason.

And of course you could just set up translation patterns CM as well for the overflow.

[mhansen]

just though i would chime in on the preference thing and some good docs...

the default preference is

preference 0

and the lower the preference the higher priority it will have.

Here are some good docs to read over just to get a feel for what is happening and the way it is supposed to work.

Understanding Inbound and Outbound Dial Peers Matching on IOS Platforms

http://www.cisco.com/warp/public/788/voip/in_dial_peer_match.html

Understanding Inbound and Outbound Dial Peers on Cisco IOS Platforms

http://www.cisco.com/en/US/tech/tk652/tk90/technologies_tech_note09186a0080147524.shtml

Configuring Dial Plans, Dial Peers, and Digit Manipulation

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a0080080aec.html

I think these docs will help.

Mike

[paolo bevilacqua]

Mike, thanks but the doubt that is taking me now, as mentioned above, is that "preference" only works for outgoing DP. The docs don't mention that explicitly. I shall test and report.

[mhansen]

yea, i am not 100% sure about the inbound dialing, it is starting to sound like you are going to need a lot of dial-peers with unique incoming called-number statements to achieve what you want. you should not have to create a translation profile for each dial-peer however you will just need to track which translation profiles will contain the rules to translate each DID you want to manipulate and assign it to the appropriate dial-peer.

[jaimeatnok]

Thanks for the replies!

From the tests I've done it doesn't seem "preference X" has any effect on incoming DP at all.

I see what you mean with regard to the need for many incoming DPs to achieve what I want. Correct me if I'm wrong (I could well be as I've come from the data world and have had to learn voice "things" pretty fast!) but if I were to have a DP with "incoming called-number 703" and another with "incoming called-number 7[0-9][0-9]", the former (703) would have a higher preference for matching than the latter (7[0-9][0-9]), correct?

At the moment I've switched the DP and it works but I can see this is a very very fine balance and precarious situation...

Would using a TCL script be a better approach?

[mhansen]

i dont have any experience with tcl but you are right in that you should try to be as clear as possible and put descriptions on all the DP's with their intended function.

you are also correct about the dial-peer matching, 703 would have a higher preference than 7[0-9][0-9] if you dialed 703.

good luck.

[paolo bevilacqua · Accepted solution]

You know, not to insinuate even more uncertainty, but I'm not even sure that 703 beats 7[0-9][0-9] on incoming DP ...

My take on doing things in tcl when regular config would do, is to look at the practical aspect of it. As long you can understand and handle the configuration approach, go with that.

[dgrosskopf]

Try changing your incoming called-number to a more specific pattern.