Utility Upgrades Its Datacomm Network to Improve Diagnostics and Reliability
"Power plans are the most-critical sities for any electic utility company," explains PP&L Data Communications Administrator James Kay. "It costs us about $10,000 to $15,000 per hour for every hour that we have a turbine off line. To replace a part rapidly means dependence on a computerized materials-management and scheduling system serving a six-state network of customer offices, division offices, district offics and power plants."
If that data communications network is out of operation for extended periods of time, or if it's improperly monitored for potential problems, the impact would be severe. The result might well be a disruption of electric service to customers and a large dollar loss to the power company. That's precisely why three years ago two major communications needs emerged: meaningful detection of line problems and user-friendly management reporting of these problems.
Old Equipment Produces Confusion
"Our old diagnostic equipment produced relative numbers describing circuit transmission quality, for example, a 2 or a 3. But what were these numbers measuring--phase jitter, signal-to-nosie, distorition?" asks Kays. "A user-friendly system would answer these questions. Even the vendor didn't know what the readings meant, so it was extremely confusing and frustrating when we'd try to get service from the telephone company. Its people would say, 'You're giving us these numbers; we want to know how you arrived at them.' So there was a significant credibility barrier between us and the phone company.
"The result of not having enough information ourselves was unnecessary downtime. In essence, the telco people just discounted our feedback, went back to square one, and performed the testing themselves, which added an average of another two hours to our downtime," Kay explains. "So I began asking myself why we had paid so much money for diagnostic equipment that didn't satisfy our needs."
An interim measure involved the use of a toll-free 800 number that put Kay in touch with an expert technician who interpreted the data. But that was far from a satisfactory long-term solution. "I still had management-reporting problems," he points out. "We scan all the trouble tickets produced during a 30-day period and generate reports from that data. But because of the relative number issue--circuit quality 2 or 3--these reports didn't give us meaningful parameters such as signal-to-noise or receive level."
RFP Leads to All-New System
An RFP was generated requesting a user-friendly diagnostic network communications system capable of handling the existing network. The system also had to be immediately expandable to 16 lines and be supported by a responsible service organization. "After a thorough evaluation, our choice came down to two vendors; we decided to go with Codex. It not only had the system we wanted--the DNCS 200--but also the required expandability, a nationwide service organization and the lowest cost, a significant 25-percent lower."
Approximately a year after installation of the DNCS, another network enhancement was made to streamline a manual customer-accounting system. "Until that time, all customer-history records, including meter readings and billings, had been maintained in tub files at each office," explains Kay. "If a user had a question about a bill, it generally took three to five minutes to retrieve the record. We needed to automate that entire procedure by implementing an on-line data-retrieval system."
With projected expansion to some 90 lines supporting almost 1,000 terminals, a detailed network analysis was in order. "I spent almost four months going through all sorts of iterations based upon minimizing the cost of line mileage, maximizing reliability and keeping pace with increasing throughput," reveals Kay. "We found that Codex had a statistical multiplexer that could handle SNA/SDLC at 9600 b/s, which is what I decided we needed. We ordered the vendor's 6050 Distributed Communications Processors (DCPs) to handle our traffic requirements and support the protocols we had."
PP&L' s datacomm network is currently configured with 10 DCPs, 37 CS 48FP 4800-b/s fast-poll modems, 125 CS 96FP 9600-b/s fast-poll modems, and sixty-two 2640 modems, all from Codex. With the increase in the number of lines from five to 90, the DNCS 200 was upgraded to a 300 system.
A variety of IBM 3274 terminal controllers, 3279 color termianls, 3287 printers, PCs and remote job-entry stations are dispersed at PP&L offices throughout its six-state area. These devices communicate with IBM 3084 and 3033 mainframes at Portland, Oregon headquarters.
Four 6050s are located at Portland, and two each are in Yakima, Washington; Casper, Wyoming; and Medford, Oregon. From each 6050 site, a series of multidrop tail circuit lines--supported by CS 96FP modems or the 2640 modem--extend in a star pattern to remote offices. The 6050s are interconnected through backbone circuits operating with 16.8-kb/s modems, so that three different communications routes are available to each processor.
While the 6050 DCPs have increased network efficiency, the DNCS has helped alleviate diagnostic interpretation frustrations. "I don't have to spend three months writing a program to get the information I want," says Kay. "We're now able to produce trouble tickets and meaningful management reports that are user-friendly. Our operators transcribe clear diagnostic messages onto trouble tickets. These messages--which are accompanied by an audible and visual alarm--appear in an English-language command set on the console screen.
"For example, the sentence," 'Signal-to-noise ratio less than 15 dB,' tells us that data is becoming compressed and we're getting into the noise area. We then run a complete analysis on the circuit, which yields not only signal-to-noise, but also receive level and harmonic distortion. We thus obtain a complete snapshot of the circuit, based upon quantitative parameters, and can make a decision on whether or not the problem is associated with a modem or a line.
"And, we have the flexibility of being able to program alarm thresholds at whatever levels we see fit. Through this control over our own destiny, we've gained credibility with the telco people. Now when we report a problem, we can supply precise, clear details, so they believe us and respond much faster than ever before."
A bonus benefit provided by the DNCS is an easing of the pressure and expense of hiring full-time specialists. "It's becoming increasingly difficult to hire technical communications experts who undersand all of the telephone company jargon as well as both analog and digital terminology," Kay points out. "Now, we don't have to carry out exhaustive searches for specially trained staff, or worry about someone filling in for someone else who's on vacation."
The 6050s are presently handling 100,000 characters of information per second on peak volume days. Says Jim Kay: "The beauty of this entire network is that, although it was initially designed for a specific application, it isn't limited to that one task. During its conception, I kept in mind that I wanted a corporate network that would not require a redesign every 6, 12 or 18 months because of some new upcoming application. And the 6050 fit this expandability concept like a glove."
But Kay readily admits that he wasn't 100-percent sure of success prior to system installation. "Today, I'm extremely pleased with the operation of the 6050s. But two and a half years ago, a major concern of mine was that we were running SNA/SDLC protocol--and could these processors handle that?" he recalls. "Installation was smooth; the 6050s immediately worked like a clock, and have been running well ever since, seven days a week, 24 hours per day. The performance has exceeded all of my expectations, with uptime running in the 99-percent range."
Economy was another plus, according to Kay. "I cost-justified the DCPs based upon the additional line mileage I'd have had to run from Portland to our other nodal sites without this hardware," he notes. "I'd have had to place nine or 10 lines from Portland to Wyoming to support Wyoming's traffic. But, by running three 16.8-kb/s links between Portland and Casper, with tail ciricuits off the 6050, the mileage I saved between Portland and Wyoming offices more than offset the cost of the processors in Casper.
"Furthermore, we now have three routes available to each 6050--as a backup measure. And this has been a big benefit. One day, I received a call from our voice communications person in Casper, who had lost all phones in his office for six hours. He wanted to know if I was also down. Three 16.8s going from Portland to Casper has been lost because someone inadvertently cut a 200-pair cable at the Casper office. Yes indeed, our alarms were on and we had lost three backbone circuits. But the 6050s automatically rerouted through Yakima and Medford, keeping the Wyoming users up and running. And none of them ever realized there had been a problem--the system is completely transparent to the end user.
Perhaps the most-useful capabilities of the 6050 have been the dynamic allocation of bandwidth and data-compression features, which improve line efficiency. "The processors always know which is the quickest route over which to send a piece of data," cites Kay. "They not only know what paths to choose, but also the transit time. Furthermore, according to the statistics we're getting from the 6050, we have achieved up to 250-percent compression, or an increase by threefold in the amount of data carried by a circuit."
Enhanced throughout and dynamic allocation have been of particular help in making optimum use of an IBM 5285 program data station. "The 5285 can function either as an RJE (remote job-entry) station or a 3270," explains Kay. "And since compression is automatic, the system dynamically adjusts to the particular usage for continuously efficient operation. We're also running graphics data, which I thought was going to be a problem because of the sizable magnitude of plottable point information. But this transmission has also gone quite smoothly."
PP&L Keeps Pace with Developments in Testing
In order to meet a continuing stream of growth needs, PP&L keeps pace with new network testing developments. The most-recent change is an upgrade of the Codex CS 48FP modems to the vendor's newly released 2640 models. "We're now replacing all of our CS 48s with the 2600 series," Kim Kay says. With these devices, the DNCS can literally tell the modem what type of test equipment the modem is to look like. For example, the 2640 with its integral 1004 Hertztone can approximate some Bell test-line capability. Since the modem's data-diagnostic capability complements the DNCS's line-diagnostic PP&L's engineering offices, estimating offices and service centers, where on-site staff are not responsible for remote testing.
"What I like about the 2640 is that it will possibly be the last piece of modem hardware I'll have to buy from this point forward," states Kay. "All changes or upgrades will be accomplished via software by adding or replacing a board at the box."
With the increased diversity of sophisticated data communications equipment, it's clear that PP&L is headed on a course toward comprehensive network control. Other plans encompass electronic mail, message switching and automated electronic meter reading.
Will the network be capable of supporting these upcoming applications? "I fell very confident about handling anything that Pacific throws my way in terms of communications," emphatically declares Kay. "I feel that with the network we've designed and the equipment we have in place that everything will function optimally. In fact, we're thinking of adding a T1 mux between our Portland and Medford nodes to handle voice/data communications."
Technologically, communications has changed dramatically since PP&L's founding in 1910. But the corporate philosophy is to continually search for new ways to improve customer service. That's why Pacific Power & Light and its 650,000 customers will continue to enjoy a bright future.
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|Date:||Aug 1, 1985|
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