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Test Database Productized

As a contractor at Nortel, I served as test department technical lead on the DMS-10 central office ISDN PRI project. Among my duties was to specify equipment to be purchased for testing.

Because the project was the implemention of ISDN PRI on a central office, purchasing one or more Nortel PBX's for lab testing was a given.

The published list price of an Option-11 suitably equipped for our needs was about $40 thousand but through internal transfer pricing, we were able to get them delivered and installed for under $15 thousand each.

Two Option 11s in the lab would provide at least one PRI span to each DMS-10 in the lab. I purchased enough line cards and phones to have two digital phones, terminal equipment and a POTS phone located in each lab area.

Once the hardware was mounted on a wall in the lab, the challenge became provisioning the digit translations (also known as dialplan) so that each valid type of PRI call could be placed per valid digit strings in the NANP.

The Nortel field service engineer I was working with had never heard of such thing and didn't think it possible. After multiple calls to the highest level of field support, we located an engineer who understood what I wanted to do which was on a per span basis have a unique three digit access code that would determine the basic ISDN PRI call type.

The Option-11 PBX would select the appropriate span based on the leading digit, call type was determined from the next 2 digits. The entire 3 digit access digits would be stripped and all remaining digits passed in properly coded messages to the DMS-10. The DMS-10 database translations then determined the exact call type and routing.

What I did on the Option-11 PBX was to setup translations in the PBX database using a 3 digit access code matching a lab DMS-10 3 digit office code range. A particular T1 board was then wired to a T1 board on the correspondingly numbered DMS-10 just to keep things consistent.

Across DMS-10s in the lab, the same philosophy held regardless of office code being 300-399 or 800-899. Once you made PRI calls on one lab switch, you could make calls to any lab switch just by dialing a different most significant digit with all other digits being the same.

I created a dialplan/translations map, added it into the dial plan for each switch and provided training on how to place and receive the calls.

Database Officially Productized

While it was just a flexible database created for lab use, it turned out Nortel sold PBX's to training centers and companies using them in lab environments such as Cisco. The advantage of this database was that customers did not need extensive training on provisioning. Just plug T1 cards and line cards into the appropriate slots. Connect the spans and lines and begin making calls. In the worst case, wiring would be wrong and the crafts person would have to reconnect wires until the calls worked.

Someone in the field group made sales/marketing management aware of this flexible database and it was subsequently productized and marketed as an official Nortel product.

I'm sure someone ultimately expanded it to include similar flexibility for non-PRI call types but at the time, PRI was a white hot commodity with ISPs and I do know the database had been successfully marketed "as is" to datacom companies.

A highly targeted niche product, the flexible database wasn't a lab tool to marketplace story like the unix operating system but it's still something to be proud of. One never knows where a path might take them. This one resulted in a lot of inquiries by Nortel's PBX group asking if I was interested in working there but I was content remaining a contractor in Nortel's central office group.

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