Lockheed Martin`s new site runs atm over fiber
By GRACE F. MURPHY
Lockheed Martin Corp., based in Bethesda, MD, is known for its cutting-edge spacecraft and military aircraft work, so it is no surprise that it has some of the fastest telecommunications technology on hand for its new Communications and Power Center in Newtown, PA, a suburb of Philadelphia.
The technology includes a $1.5 million, 1500-user Ethernet and Asynchronous Transfer Mode (atm) network with OmniSwitches from Xylan Corp., Calabasas, CA, that are capable of handling multiple fibers transmitting at OC-12 (622-Mbit/sec) rates at each port.
William Dilworth, a communications design analyst for Lockheed Martin, says the company went into the project searching for a system that could handle the new facility`s high-traffic needs. Users who were to perform bandwidth-intensive activities, such as designing circuit boards, satellite components, RF systems, power systems, and antenna systems, wanted a network that would allow them to draw online using computer-aided design systems and then store their work on two Sun Ultra 5000 machines.
The facility opened in July with a network that does just that and allows manufacturing shop users to pull the drawings up on their desktops. The facility currently has approximately 700 data drops in the shop intended for automated print serving, according to Dilworth.
"It was also a requirement for multimedia, the combination of multimedia, moving drawings back and forth between the engineers, the computer, and the technicians," he says. "That`s what took us into requirements for a very high-speed network and high-capacity switches."
When the company was planning the new building in late 1995 and early 1996, Dilworth says the available options--Ethernet at 10 Mbits/sec and Fast Ethernet at 100 Mbits/sec--weren`t fast enough.
"We were looking for something faster than that, and the only thing out there basically was atm at OC-3 speeds of 155 Mbits/sec, with atm OC-12 622-Mbit/sec speeds just around the corner. So we designed toward the 622-Mbit/sec network, knowing that we were at least a year away from installing this building," Dilworth says.
The facility consists of a 70,000-sq-ft administrative building with low computer usage and a 350,000-sq-ft building that houses the manufacturing, engineering, and accounting departments. There is also a 1500-ft, 24-strand length of multimode fiber-optic cable laid between the smaller building and neighboring Holy Family College, where personnel will be trained on software packages.
A 4-inch conduit of multimode, 96-strand fiber-optic cable encased in concrete connects the computer room in the administrative building to a main telecommunications closet in the second building. After breaking out on two adjacent Lucent Technologies` patch panels, the cable runs to seven closets. Ethernet traffic is distributed from the closets on enhanced Category 5 copper cable. Of the 24 strands of multimode cable running to each closet, 4 to 8 are actually in use, Dilworth says.
There are also eight strands of fiber-optic singlemode fiber running to each closet, which were included in the system for future growth needs.
"I`m hearing rumors in our industry that Gigabit Ethernet is having problems running on multimode fiber, but no problems with singlemode, so it`s there in case [the rumor] is true and I should decide to include Gigabit Ethernet," Dilworth says.
Lockheed Martin looked at switches from five vendors and selected the OmniSwitch. Each operates at a capacity of 144 users and runs at 10 Mbits/sec to the desktop but is capable of carrying traffic at 100 Mbits/sec. The company intends to use the switches` 10/100-autosensing capability by the end of 1998.
Integrating subnetworks
There are five subnetworks in use, and a user`s network is determined by his or her Internet protocol (IP) address. The switch is also capable of determining the address based on the first IP packet sent out.
Traffic is sent from the networks into the switch and run over fiber uplinks at OC-3 rates back to the main computer room in the smaller building. Dilworth expects that the uplinks will run at OC-12 rates by the end of February. The facility`s four Sun Ultra servers now operate at OC-12, as do four core cell switches that link the closet uplinks and servers together (see figure).
"Those uplinks [at 155 Mbits/sec] are only until we prove that everything`s working fine, and then we`re going to change to twin 622-Mbit/sec uplinks. We actually bought the 622s, but we`re going to run the 155s until we feel confident-- this is all leading-edge stuff," he says.
Xylan officials say the OmniSwitch is designed to make it easy for networks to evolve, since it can handle different speeds and protocols.
"This is on par with what we excel at, which is the very complicated, multiple protocol type network where there is a need to have a high level of integration. What they really need is to have all these different types of data systems and what we`ve talked about--Ethernet, Fast Ethernet, OC-3 atm, OC-12 atm," says David Rodewald, Xylan`s director of corporate communications.
Doug Hill, vice president of corporate communications at Xylan, says the atm backbone should suit Lockheed Martin`s needs well. "By putting in an atm backbone on campus, what people are doing is two things--they`re putting in a backbone that they`ll be able to run at any speed they will need over time," Hill says. "The second thing they`re doing is putting in a strategic backbone that allows them--when they want--to run video and voice as well as data across the backbone." q