How Can We Set Which PSTN Lines Are Selected On An Outbound Call?

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May 2nd, 2010
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We have a situation where we use a UC540 with 3 lines from a local telco carrier, and we have 3 Vonage lines. We would like to be able to have our UC540 use the 3 vonage lines first when someone from our office dials out. How can we set up the outgoing dial plan to select the Vonage lines first before the local telco lines?

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David Trad Mon, 05/03/2010 - 00:47
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Hi Farr,

There is two ways you can do this, I guess you just have to pick which one you think it best suited for you or your client:

Trunk Line Monitoring

This is done by creating a series of DN's and Dial-Peers and then assigning the DN's to a button, I do not believe CCA can do this yet (Happy to be corrected on this) but it can easily be done via CLI, although I believe my method may not be OOB complian. However you will then need to train the users to use "0" or what ever number you prefer for dialing out over the vonage, and have a set of VOIP dial-peers setup for this, and also have first preference, and then use the trunks lines when all your vonage channels are full.

  • Dial-Peer controls
    Basically this is the most easiest and less fuss, you pretty much duplicate your dial-peers, Vonage are your VOIP dial-peers and should have a preference of 1 and your PSTN lines are your POTS dial-peers and they have a preference of 2. What this means is that when they dial "0" to get an outside line, and then dial the number, it will match the VOIP dial-peer and the POTS dial-peer but call out first on the one that has preference 1 set, and if that is full or not able to be used it will dial out on preference 2

Option number 2 is the recommended one, since you can not monitor SIP trunks (Well not that I am aware of) you are better of controlling the calls from one single point, that being your dial-peers, the bonus with option 2 is that you can set this up using CCA :)

Hope this information helps you out.



Steven DiStefano Mon, 05/03/2010 - 12:31
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Couple of CCA options for outgoing call selection:

CCA supported Button type called CO Line, which you can assign to phone buttons.

When you press that button, you get dialtone fromthe line connected to that FXO port.  You can have as many as you need and assign to multiple phones who are authorized to share them.

CCA --Configure: Dial Plan: Outgoing has two tabs.

PSTN Trunk Groups lets you assign custom groups of FXO lines into trunk groups.

The Outgoing Call handling tab also allows you to 'prefer' PSTN or SIP, Only PSTN, Only SIP, SIP Then PSTN and then configure priority, which lets you say in what order you want to use the trunk groups.

Note: this is on an 'access code' wide basis, meaning every phone connected to UC500 will use this preference order.

I think this latter option may work well for you.   I take it the vonage lines are plugged into FXO ports like the telco lines?


farrshepherd Mon, 05/03/2010 - 16:19
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Thanks Steve, this is helpful.

Currently our Vonage lines are not coming in to the router as SIP trunks. There is a modem and they feed in to the router via an RJ11 jack. So as far as the UC540 is concerned we have 8 PSTN lines. Is there a way I can create 2 Trunks to break up the PSTN lines in to 2 groups, then I can use the Dial plan to set it up to automatically dial out on those lines. This will eliminate the need for me to set up all the lines via CO buttons on all users phones.



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Steven DiStefano Mon, 05/03/2010 - 16:24
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Yes, that was the 2nd option I described. Build two trunk groups with

vonage having preference so it gets used first. This should work.

farrshepherd Wed, 05/05/2010 - 20:38
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I was trying to add a new Trunk Group but there was nothing available to add. I didn't realize I had to remove them from the original group first to make them available to add to another group. So now that I have done that I have assigned them to the dial plan and that seems to work fine. Thank you very much!

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