Navy finds place for ATM and Gigabit Ethernet on nets
SAN DIEGO—When it comes to large-scale enterprises, the Navy will stick with asynchronous transfer mode technology for backbone connectivity. But newer technologies such as Gigabit Ethernet, which offers a tenfold increase in transmission speed over Fast Ethernet's 100 Mbps, are finding their way into some of the Navy's small and midsize networks.
SAN DIEGOWhen it comes to large-scale enterprises, the Navy will stick with
asynchronous transfer mode technology for backbone connectivity.
But newer technologies such as Gigabit Ethernet, which offers a tenfold increase in
transmission speed over Fast Ethernets 100 Mbps, are finding their way into some of
the Navys small and midsize networks.
We have some places that are using Gigabit Ethernet today, such as the
Naval Post-Graduate School, Adm. Archie Clemins, commander of Pacific Fleet, said
at last months West 99 conference. But
I will tell you that as a standard right now on the horizon, ATM technology appears to
be the way to go with the most advantage for us both at sea and ashore.
ATM, which delivers voice, video and data at speeds as high as OC-12, is a more mature
technology than Gigabit Ethernet, has established quality-of-service standards and
integrates more easily with token-ring and carrier networks. Gigabit Ethernet, however, is
less expensive and less complex than ATM and integrates more easily with existing Ethernet
networks.
There are probably some places in the Navy that dont need voice, data and
video integrated together in the future, Clemins said. Once you find those
places, you have to make the trade-off and ask yourself the question: If you have a whole
structure set up to manage ATM, is it cost-effective to put in small pockets of Gigabit
Ethernet?
For shore facilities with an existing investment in ATM, there is no compelling reason
not to have both ATM and Gigabit Ethernet on the same network, Clemins said. But the
configuration and administration issues of supporting two different technologies must be
weighed carefully, he said.
Gigabit Ethernet is easy to configure and administer by administrators already familiar
with Ethernet.
But it also requires more work to establish quality-of-service standards over a WAN
link, and it does not have the scalability and bandwidth flexibility that ATM does,
Clemins said.
Were looking at that, and those are some of the business decisions that are
involved, he said. ATM LANs aboard ships, however, are still the standard
because you buy all the ATM cards and put in ATM to the desktop.
But ATM equipment, including network interface cards, switches and routers, are more
expensive than Gigabit Ethernet segments. Prices for both technologies have been dropping
rapidly.
Pacific Fleet is taking advantage of falling prices to install ATM LANs and connections
that will link military bases throughout the Hawaiian island of Oahu. Fore Systems Inc. is
building the ATM backbone for the Oahu Base Area Network (OBAN) in Hawaii, linking about
4,000 PCs.
The Warrendale, Pa., company installed a 500-PC network at Pacific Fleets Pearl
Harbor headquarters last year as a pilot in preparation for OBAN. Fores ForeRunner
ASX-1000 and ASX-200BX ATM switches support an OC-12 backbone that connects more than 30
buildings.
ForeRunnerLE 155 ATM workgroup switches connect the 4,000 PCs at speeds of 155 Mbps.
Fores PowerHub 7000 and 8000 multilayer LAN switches provide LAN emulation services,
routing and switched Ethernet connectivity for non-ATM systems.
The Navy will establish a regional information technology service center in Oahu to
oversee network management and provide connections between its client LANs as part of
OBAN.
The center will provide Secret IP Router Network, Non-Classified IP Router Network and
Internet services, as well as centralized e-mail, Defense Message System and firewall
support.
A worldwide intranet linking command centers and ships is the Navys ultimate goal
under the Navys Information Technology for the 21st Century initiative, Clemins
said, and ATM technology is the enabler.
Gregory Slabodkin