Network computers may be touted as the latest weapon in the war to control desktop costs, but supporting them on the server and the network side of the equation could neutralise their punch.
Users of network computers will have to bulk up their LAN and WAN infrastructure, even though the cost of doing so could easily wipe out anticipated savings associated with buying the lower-cost boxes rather than PCs, according to internetworking vendors.
"The reason X terminals didn't take off was because the infrastructure was hubs and routers and couldn't support the traffic. Didn't everybody complain about the lack of bandwidth when they wanted to run remote graphical applications back then?" says Trent Waterhouse, programme manager for LAN switching at Cabletron Systems, in Rochester, New Hampshire.
Rob Newman, vice-president of LAN backbone products at Bay Networks, in Santa
Clara, California, agrees.
"The increase in bandwidth required by network computers will be pretty dramatic. WAN charges alone could negate any savings realised by buying network computers over PCs," he says.
Users will need network upgrades from hubs and routers to LAN switches to assure proper performance for network computer users, Newman cautions.
The increase in traffic will depend on which applications network computer users access.
Server vendors are making similar claims, saying those machines will need to be beefed up and clustered to give high performance and reliability to users who will be stranded without server and network connections.
For example, Digital is telling customers that if they generally allot 500Mb to 1Gb of memory per PC, they can expect to cut memory allotment by 40% on a network computer support server because users won't all be using their space at the same time.
But when the server must support more than 100 users, processor and memory requirements can increase, depending on the type of applications.
Network computers will change the way users design networks, says Jayshree Ullal, vice-president of marketing at Cisco's workgroup switch business unit. "The 80-to-20 rule that said 80% of all traffic is local and 20% is remote will become a thing of the past."
And these changes mean traffic from network computers will have to travel longer distances to reach servers, be they on the other end of a campus network or a far-flung intranet site.
That means upgrading to switching all along the path from the desktop to the data centre.
Users will need LAN switching at speeds of 10Mbit/s, 100Mbit/s and even beyond to bulk up their campus LANs for network computers.
Getting the same size pipes on the WAN side will be tough and expensive.
LAN bandwidth is cheaper than WAN bandwidth, Newman says. "So unless you stop the network computing model at the campus boundaries, you can expect dramatically higher WAN charges." That is because the WAN is the bandwidth bottleneck.
Users with local servers will need Ethernet switches to provide dedicated bandwidth to each network computer and a fatter pipe to the server.
Information systems managers can expect to pay about US$3975 for a 12-port Ethernet switch and US$4975 for a 24-port unit.
But vendors agree that most users centrally locate servers in data centres on backbone networks.
Some workgroup switches don't come with high-speed uplinks needed to link to bigger switches. Buying them can cost IS managers US$700 to US$5000, depending on the technology used. Vendors recommend either a Fast Ethernet or Asynchronous Transfer Mode (ATM) backbone switch.
Users can expect to pay roughly US$7500 to US$8000 for a Fast Ethernet switch with eight 100Mbit/s ports or about US$15,000 for a comparable ATM switch, vendors say.