PTO net suffers growing pains
- By William Jackson
- Nov 10, 1997
If completed as planned in November, the PTO Integrated Network will have more than 20
ASX 1000 10-gigabit/sec backbone switches from the Pittsburgh company, plus 150 PowerHub
7000 closet switches.
"This will be one of the biggest PowerHub installations in the country," said
PTO computer engineer Wes Clark, who oversees the network.
A recent experience with a bad batch of PowerHub cards had PTO officials rethinking the
strategy, though it seems unlikely they will change vendors.
"We can't make a decision whether to dump the PowerHub or not," Clark said.
"It seems a little late in the process to do that. We're going to have to make the
PowerHubs work in this environment. It's been a long process, and we're not entirely
There have been other problems updating code in the ASX 1000 switches already
installed, he said.
Fore Systems representatives attributed the problems to a batch of bad cards that
escaped a screening process because of a mix-up in serial numbers.
"It's not a big deal," said Stephen J. White, manager of Fore's technical
product marketing. "The issues have been identified, and they are all
correctable." Spare cards are available on site to replace the bad ones, he said.
PTO officials, however, were unhappy that they were not notified earlier of the bad
"We had this sort of conversation about incremental disclosure about a year
ago," Clark said.
The integrated network will replace a pair of Fiber Distributed Data Interface rings
that support separate networks for office automation and the Automated Patent System. The
ATM network will bring switched Ethernet to the desktop PCs of thousands of patent and
trademark examiners who access millions of online images.
The new network will more than triple the 3 megabits/sec delivered to PCs by the old
FDDI "served us well, but it cannot meet the bandwidth requirements of the near
future," Clark said. "Our customers are demanding new capabilities."
The demands arise because the number of patent applications received each year is
expected to grow from 212,000 in 1997 to 258,000 in 2002, and Congress wants PTO to
maintain or reduce the average 18-month turnaround time.
Over the same period, the number of trademark applications filed each year is expected
to go from 218,000 to 351,000.
The increased workload requires hiring more examiners, who analyze more than 200 years'
worth of patent and trademark documents. This work is speeding up under the Automated
Patent System, which replaces boxes of paper documents with digital images on Unix
servers. The automated system now has 27 terabytes online in a server farm.
APS in the past has run on three FDDI rings connected by routers with hubs to deliver
shared Ethernet to examiners' PCs. In an early step toward integration, the network in
1993 joined via a 100-megabit/sec link to the single-ring FDDI office automation network.
The PTO Integrated Network eventually will provide a common transport facility, making
all PTO applications accessible from all PCs.
ATM was the choice for the network because it can best serve future needs, Clark said.
PTO will pilot a PC video system next year, and further plans call for a telephone switch
to blend data and voice networks on the campus LAN.
"We're just now starting to investigate that," Clark said. "ATM seems
suitable for that kind of multimedia. Also, we're trying to emulate what private industry
is doing," and most businesses with high-bandwidth requirements are going to ATM, he
The design of the integrated network brought its own challenges. PTO has offices in 16
buildings spread over a mile along Jefferson Davis Highway in the Crystal City area of
Arlington, and people relocate frequently from office to office.
"We try to accommodate them with network drops," Clark said.
"But we don't have a procedure for removing them," he said.
The network constantly changes, so administrators have no clear picture of what is and
what is not on it. "We had problems trying to design to a moving target," Clark
A second problem was the aging fiber-optic infrastructure of the Crystal City complex.
The original cabling, some installed a dozen years ago, has deteriorated in places and
made circuits unstable. In many buildings, more cable is being pulled.
PTO also wants redundant Sonet OC-12 lines between buildings. As Navy offices move out
of Crystal City, PTO is using their cable where possible to establish redundant links.
The switches have been another problem. No other product came as close to meeting PTO's
needs for a robust closet switch as Fore's PowerHub.
When deployment began earlier this year, however, the 7000 was a "bleeding-edge
box," one engineer said.
"We had some teething problems" with the switches, White said.
Fore and systems integrator Signal Corp. of Fairfax, Va., have worked hard to eliminate
bugs and give the PowerHub 7000 the reliability PTO needs. "Signal has been doing
yeoman service on this," Clark said.
"PTO is an extremely demanding customer," White said.
White acknowledged PTO has to be a stickler for network reliability, because any
downtime idles highly paid attorneys and examiners. "It's hell to pay," he said.
"Our cash flow depends on our network," Clark said. The outcome should be a
robust network that will fill PTO's needs into the next century.
"It really would take a lot to bring this network down," White said.
William Jackson is a Maryland-based freelance writer.