The Paranoid Undertaker
It would be easy to mistake the Baldwin Park central office for a museum of the history of telephony: the building has hosted three generations of phone network technology since its construction early in the last century. The first and longest-lived technology was the step switch. Legend says that its inventor, a Kansas City mortician named Almon B. Strowger, was convinced that switchboard operators were sending his customers to rivals. So he built an electromechanical device that automatically routed calls according to the numbers dialed by customers and patented it in 1891. For decades, step switches occupied thousands of central offices, whirring, clicking, and banging as they opened circuits and shunted calls to their destinations.
In Baldwin Park, the mechanical step switches were finally ripped out in the 1970s and replaced with digital switches. All that’s left of the old apparatus are two walls of steel coils big enough to hold wine bottles. Now 11 rows of digital circuit-switching equipment house thousands of playing-card-sized circuit boards. Copper wires running from homes and businesses across Baldwin Park and parts of adjacent communities terminate here; to the phone network, these circuit boards are you, me, and our neighbors and employers.
In circuit-switched networks like Baldwin Park’s, a given phone call has exclusive access to a circuit, or phone line, for its entire duration. “The minute you dial your number…you’ve tied up a certain amount of bandwidth,” says Stuart Elby, Verizon’s vice president of network architecture and enterprise technologies. “So you waste a lot of space.” But the share of phone network capacity devoted to voice calls is declining fast, while data traffic is increasing, and today’s third wave of change – the transition to packet switching – is a response to that shift.
Packets are dollops of information labeled with addresses so that a computer network can forward them, node by node, to their intended recipients. As long as each packet is reunited with its neighbors at its destination, it doesn’t matter how it gets there – which means that billions of packets with different destinations can travel through the same physical wires at the same time. Though it’s the very foundation of the Internet, packet switching is a relatively old technology, first developed in the 1960s. But turning voices into packets is relatively new, and until recently the audio quality of packet-switched calls lagged far behind that of circuit-switched calls. As recently as three years ago, most engineers at traditional phone companies still sneered at packet switching. “Saying that Internet Protocol was going to be the most important protocol – well, that could be a career-limiting move,” laughs Elby.
No one’s sneering now. Verizon’s biggest fear is missing the opportunity presented by packet switching, which cable companies like Comcast are quickly seizing upon to offer voice and data services in addition to their traditional TV packages. Packet-switched networks are not only more capacious; they’re also cheaper to run. A single 100-centimeter-by-60-centimeter “softswitch” – so called because it uses software commands to handle both Internet-type packets and the older data formats used for many voice calls – accommodates as many phone lines as a 10-meter row of digital circuit switches. That saves on maintenance, and even better, it means Verizon can combine central offices: another California office, for instance, will be managed remotely by software running at Baldwin Park.
Verizon set a highly ambitious schedule for the first rollout of its new packet-switching equipment. The southern-California team assembled at the Baldwin Park office one day in early August gripes good-naturedly about the pace. Lead engineer Bill McClure says that during a conference call in February, he and fellow lead engineer Curtis E. Reese learned that they’d have until July 2 to refit five sites that handled a total of 100,000 telephone lines – a shock to engineers accustomed to testing small things for 18 months apiece. “When they said that, Curt passed out,” jokes McClure, a 32-year veteran of the company. “And then I passed out.”
“And then they told me, and I passed out,” chimes in Pamela Jacoby, the project leader. They recovered fast: this is, after all, the kind of assignment that caps a network engineer’s career. But that doesn’t make it easy. There have been plenty of double shifts and unexpected bugs. Baldwin Park is one of the first and biggest central offices to convert to packet switching, and impromptu conference calls between Verizon engineers and their counterparts at telecom equipment supplier Nortel can happen several times a day.
Getting the new equipment to work with older ISDN technology was one stubborn problem. It also showed what it will take to integrate packet-switching with the old phone network, which Verizon can’t simply turn off. Many retail and banking customers still send credit card and other transactions over ISDN connections, a 1990s predecessor to DSL. But the information traveling on one of the ISDN data channels wouldn’t transfer over to the packet switches. “That took three or four weeks to figure out,” Reese says.
The team missed the July 2 deadline, largely because of state regulations requiring phone companies to give 30 days’ notice of equipment changes. But the delay gave the team extra time to resolve technical problems like the ISDN bug. Verizon’s first fully packet-switched central office went live in mid-September; at press time, however, the changeover at Baldwin Park was temporarily on hold while Verizon attempted to resolve related legal issues.
Those first five stations handle only a small fraction of Verizon’s customers in the region, but the pace of the rollout is expected to increase, and the company’s entire network could be converted in as little as five years. It’ll be a while before customers actually see a difference in services; Verizon won’t become an amalgamated phone-cable-broadband company with gee-whiz packet-switched services until it actually has a good base of switches in place. But already, thanks to a parallel effort at Verizon to string fiber-optic cables from the curbside all the way into people’s living rooms, Verizon customers in places like Keller, TX, Tampa, FL, and Huntington Beach, CA, have spiffy new “optical network terminals” pumping up to four phone lines, television service, and 30 megabits per second of data into their homes (DSL tops out at about three megabits per second).