The following is a technical history of the former North Pittsburgh Telephone Company from 1983 to the acquisition of the company by Consolidated Communications in 2008, based upon the Telephone World webmaster’s personal perspective. It may not be totally accurate but should be a good guide.
Conversion from Analog to Digital
By the early 1980s, North Pittsburgh started the long and involved process of converting their central offices from a mix of analog switches to all digital switching. For many reasons (especially with the breakup of AT&T and Equal Access and SS7 signalling), North Pittsburgh spent seven years installing a network of digital swtiching systems in all their exchanges.
NPT chose the Northern Telecom (now Nortel) DMS-100 series of digital switches with a DMS-100/200 to serve as a host switch and as tandem in the Gibsonia exchange. The Wexford exchange also received a DMS-100 host switch. All the other exchanges were Northern Telecom Remote Switching Centers (RSC), which homed on the Gibsonia host switch. The exception was the Criders Corners exchange which homed on the Wexford switch instead.
The first office to be converted over to the DMS-100 was the Gibsonia Step by Step switch in March 1983. Since this served as the tandem for the other Step by Step switches, this made sense. However, the only line numbers to be converted over to the DMS-100 were the line numbers originally served by the Step by Step switch (the 2, 3, and 9 thousand blocks). The other line numbers that were served off the Automatic Electric #1EAX continued to do so until much later.
After the Gibsonia exchange “partial conversion” to the DMS-100, other exchanges followed over the next several years at the rate of about 2 prefixes per year. First the Step by Step systems were converted, the #2EAX systems were then converted, and finally the #1EAX in June 1987.
When the Gibsonia DMS-100 switch was installed, inter-switch tandem functions within NPT territory were transferred to the DMS-100 switch. Calls originating on the #1EAX were sent to the DMS-100 via MF. Outpulsing to the other Step by Step switches were handled now by the DMS-100 (with VERY faint outpulsing).
Automated Intercepts were handled in an interesting way. If the number you dialed was a non-working number on the DMS-100, the DMS-100 would MF the number to the #1EAX, then the #1EAX would MF the number to the Cognitronics AIS machine. If the call originated from the #1EAX, you would hear THREE MF strings – the original MF from the #1EAX to the DMS-100, the DMS-100 back to the #1EAX, and then the #1EAX to the AIS machine (whew!)
Long distance calls from the DMS-100 offices were probably accomplished from the very beginning with SS7 technology, as I never heard MF for long distance calls from a DMS switch. I assume that toll calls originating on the #1EAX were sent to the DMS-100, and then sent to a regional or toll tandem (AT&T 4ESS or the regional Bell Atlantic DMS-200 tandem in Pittsburgh).
After the final conversion of folding the Gibsonia #1EAX customers into the existing DMS-100, NPT did use an AIS system in association with DMS-100. This was later dropped for most non-working numbers and utilized centralized intercept instead. The exception to this rule is when a customer moves and requests a forwarding number. NPT will program the AIS for a period of 60 days from the time the customer disconnects service.
Cellular and CLEC services
Prior to the late 1990s, North Pittsburgh had an IMTS (Improved Mobile Telephone System), which predates modern cellular telephone technology. This system was decommissioned in 1997.
By the late 1980s and early 1990s, cellular were installed in North Pittsburgh territory and other rural telco territories in western Pennsylvania. At that time, most cellular numbers were assigned to the Pittsburgh ratecenter or that of some suburbs of Pittsburgh. By the mid 1990s, numbers were assigned to ratecenters within NPTCo territory – first the Criders Corners ratecenter, later the Gibsonia, Wexford and Saxonburg ratecenters.
Most of these calls weren’t actually “switched” within NPT territory. These calls were forwarded to switches elsewhere (normally in Pittsburgh). At first, NPT assigned regional long distance charges (Intra-LATA) to these calls even though they were supposed to be dialed as an uncharged/untimed local call to a North Pittsburgh ratecenter. Eventually NPTCo wised up and changed these to uncharged calls even though they were sent elsewhere to be switched.
By the early 2000s, a new cellular tower was built where the old IMTS tower once stood. Verizon Wireless (and the Sprint side of T-Mobile) share tower space.
Penn Telecom, the business division of NPT offered CLEC services in various places in the 412 and 724 area codes. They either have a second DMS-100 switch in the same building as the Gibsonia DMS-100/200 switch, or use the same switch but for CLEC functions.
1990s to 2007
NPT (later known as North Pittsburgh Systems, Inc) was now a full fledged telecommunications company, offering full Internet services (marketed as Nauticom), business systems (marketed as Penn Telecom), long distance (marketed once as Penn Telecom, later as North Pittsburgh Long Distance) and offered Competitive Local Exchange Service to various ratecenters in Verizon and CenturyLink (former Embarq/Sprint/United Telephone) territory.
In the 1996, the Telecommunications Act of 1996 was passed and required all telephone companies to create separate divisions for their pay phone services. North Pittsburgh chose to sell their pay phones to a third party company. This company took over all existing NPT pay phones and converted them to COCOTs (Customer Owned Coin Operated Telephone) in the fall of 1999. I am not sure if this company (who’s name I don’t recall) offers new service or not. (Update – as of the end of 2004, almost all these pay phones have been removed due to lack of use.)
In February 1998, the 412 area code was split into two area codes. Pittsburgh and its immediate suburbs retained 412, the rest became 724. The first draft of the split line would have split part of NPT territory into 412 (south of the Allegheny/Butler county line) and the rest into 724. The final split line was the border of Bell Atlantic (now Verizon) and the former North Pittsburgh territory. Hence all of former NPT’s ratecenters are in the 724 area code.
In August 2001, the 878 area code was introduced to overlay both 412 and 724 area codes, and with that came mandatory 10-digit dialing. Only in the mid to late 2010s and the early 2020s central office codes (prefixes) are now being assigned in 878, but everyone in the 412 and 724 area codes must dial their numbers with all 10 digits.
Acquisition by Consolidated Communications
North Pittsburgh Systems, Inc. (parent company) was sold to Consolidated Communications of Mattoon, Illinois in 2007, with the sale and acquisition complete in January 2008.
There were many reasons why the company was sold, but the primary problem was competition from non-traditional telephone services (Cellular, VoIP, etc.). The company was beginning to lose up to 10% of its customer base and start losing money. Hedgefund owners were not happy and forced the company to sell.
List of North Pittsburgh Telephone Company Unofficial History Pages
About the North Pittsburgh Telephone Company
Information about the former North Pittsburgh Telephone Company and its affiliated companies.
Personal Interest of North Pittsburgh Telephone Company Part 1
Background on the personal interest and recollection of the former North Pittsburgh Telephone Company from the Telephone World webmaster’s perspective.
Personal Interest of North Pittsburgh Telephone Company Part 2
More information on the personal interest and recollection of the former North Pittsburgh Telephone Company.
North Pittsburgh Telephone Technical History Timeline Part 1 (1906-1959)
A technical history of the North Pittsburgh Telephone Company from 1906 to 1959 from the prospective of the Telephone World webmaster.
North Pittsburgh Telephone Technical History Timeline Part 2 (1960-1980)
A technical history of the North Pittsburgh Telephone Company from 1960 to 1980 from the prospective of the Telephone World webmaster.
North Pittsburgh Telephone Technical History Timeline Part 3 (1980-2007)
A technical history of the North Pittsburgh Telephone Company from 1980 to 2007 from the prospective of the Telephone World webmaster.
Epilogue: Consolidated Communications of Pennsylvania (2008 to Present Day)
An epilogue of what happened post merger with Consolidated Communications.
North Pittsburgh Telephone Company Central Office Building & Miscellaneous Pictures
Pictures and information on the central office buildings and associated equipment for the former North Pittsburgh Telephone Company.