Mitel 3300, MCD , 3Com NBX 3000, Call Restrictions between systems via PRI issues.

Posted on 2014-03-22
Last Modified: 2014-05-28
We have a 3com nbx 3000 that is our main system that is connected to a secondary Mitel 3300 via PRI.  

Extensions that are on the mitel are set in the dialplan of the NBX to route to the Mitel.

The issue I am having is that when I want to restrict a phone on the Mitel to only dial internal extensions, it doesn't consider the extensions on the 3com as this, therefore they are denied.

Is there a way to setup a class of restrictions that uses a list of extensions as exceptions? or is there something i'm missing that needs to be added to allow the mitel access to the extensions that are across the PRI.
Question by:Multitasker1
LVL 17

Accepted Solution

JRSCGI earned 500 total points
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Because the extensions on the NBX are not extensions on the Mitel they are not allowed by an extension-only definition.  In other, calls that need to traverse a trunk group (the PRI tie line) are not considered internal to the Mitel.  You can set a class of service in the Mitel that allows internal (to the Mitel) plus calls that use the tie line (allow via trunk access code) but it would take special programming in the NBX to prevent such a user from then dialing an outbound call through the NBX.  Not sure if/how to do that in the NBX unless ALL calls from the Mitel are to be kept as site to site calls only (then you could restrict calling on the tie line).  If the Mitel has its own outside trunks, maybe this is ok.

Another way to do this might be to create extensions in the Mitel that map to the extensions in the NBX,  Then those extensions can be set to forward across the tie line so that Mitel users are only dialing an extension string.  The Mitel users that need to be restricted to internal calls now need a restriction settings that deny all trunk access codes (as defined in the dial plan) rather than the generic internal only definition.  Thus, the specific restricted extension could dial four digit calls on the Mitel only, just that some of those four digit extensions would route over to the NBX.  The biggest disadvantage to this plan is that you need additional extension / user licenses in the Mitel to set up each extension that is forwarded to the NBX.  If there are many required, this is going to carry a significant cost.

The one other possibility is the use of "system speed dials" that are setup in the Mitel per internal NBX extension.  This overcomes the extension licensing problem above as well as complies with the dial plan access code restrictions needed.  I know this works in other PBX systems but have to research if it works on a Mitel.  The concept is create a speed dial entry that includes the PRI tie trunk access code plus one extension on the NBX.  Then see if the restricted station on the Mitel can dial the speed dial entry to overcome the trunk restrictions.

Author Comment

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Thank you very much for the detailed answer, please accept my appologies for the late reply.  I'm going to look into your system speed dial theory and do some testing.   I'll report back in a couple days.  Once again thank you very much for your insight!!

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