We help IT Professionals succeed at work.

voip pbx bridge

bcdudley used Ask the Experts™
I have two phone systems that I would like to be able to talk to each other. One is a Mitel system that has approximately 400 phones on it. The other is a Cisco system with a couple thousand phones. I am looking for some type of bridge to allow 4 or 5 digit dialing between the 2 systems.
Any recommendations as to what I should be looking at.
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
It is possible to directly connect the two systems in most instances.  Each system would be programmed with an ISDN-PRI tie line link.  The extension range for the opposite system is placed in a dial plan table that directs the calls to the tie line, which then "repeats" the appropriate digits for the other system to process, thus giving you the extension dialing between them.  This does not require a gateway or bridge in this situation.  All that is needed is a T1 card in the Mitel and a T1 WIC in the Cisco gateway.  If the two systems are directly connected (such as on a common campus) then you wire a four wire circuit between them to match the T1 pinouts.  If they are separated by distance, you can order a circuit from your carrier.  If you have data connectivity between the two, you can replace the T1 cards with an IP based trunk, still set up as a Tie-Line.
To enhance the communications between the two systems, each can activate QSIG.  This may give the called party more information, such as the extension number of the caller instead of just a generic ID that it is coming from the other system.
If you have a support vendor for the systems this is a common requirement and relatively routine.  If you are attempitng to program it yourself, you will need some precise instructions but probably can get it done.

If they are not co-located you can still use QSIG over a PTP T1 or you can use SIP trunking between the 2.  You may lose a feature or 2 with SIP.


Thank you for the answers.

We currently have numerous overlapping extensions on either side. Both systems are usign 4 digit dialing.  We would like to set it up so that a 5th preceeding digit will dial the number on the other system. Will this be possible to do with the setup you have described?
sure - it is possible with both.  In your ARS digits dialed programming (on the Mitel, not sure where on the Cisco) you would add say an 8 with 4 to follow goes out route 20 where route 20 = the QSIG or SIP route to the Cisco switch.  Then on the Cisco switch on SIP/QSIG inbound calls you would strip the 8 - aka absorb 1.  Absorb 1 leaves you with 4 left that will match an extension on the Cisco side.
Same in reverse for Mitel.


Thank you. This has been very helpful.