New technologies give twist to cabling

Wireless technologies such as Wi-Fi, Bluetooth and 802.11a are hot network topics, but more than 90 per cent of LANs are still hardwired. While the different cable types in LANs are fairly standard and unchanging, companies are using new technologies to make the most of their wiring infrastructures.

Products such as copper-based Gigabit Ethernet let users run high-speed networks without having to totally invest in a fibre-optic infrastructure, while other customers find ways to use older phone wiring to deliver voice over IP and even Ethernet connectivity.

With Category 5 and Category 5e cabling making up 80 per cent of corporate network wiring, 1000Base-T technology – which lets Gigabit Ethernet run over Cat 5 – has taken off with users, letting them run high data links over old wiring for short distances.

According to Dell’Oro Group, the average Gigabit Ethernet port cost US$544 in the third quarter of 2001. Meanwhile, vendors such as 3Com Corp. and Cisco Systems Inc. and smaller makers such as D-Link and Linksys offer 1000Base-T switches priced between US$90 and US$200 per port, making the technology affordable.

To some users, an added bonus of 1000Base-T technology is that it gives them a means to perform minor cable runs and maintenance themselves, whereas previously a professional would have to do even small fibre runs and cable termination.

Beiersdorf, a Norwalk, Conn., skin care company, uses 1000Base-T switches from Cisco and copper Gigabit network interface cards from Intel to attach servers to its Gigabit Ethernet network.

The firm also runs Gigabit over Cat 5 wiring between its backbone stack of switches and its wiring closets.

For longer Gigabit connections – such as connecting groups of backbone switches across the building – the firm uses multimode, fibre-optic cabling, but the majority of the company’s Gigabit links are over Cat 5.

“For all our fibre connections, we have to get someone from outside to do them,” says Eric Mucci, Beiersdorf’s head of IT. “As for copper in-house, we can handle that.”

Wiring fibre-optic cabling in-house requires expensive tools to polish fibre strands and terminate the links, Mucci says, whereas Cat 5 wiring requires fairly inexpensive tools – such as a connection crimper and a punch-down tool – and can be learned fairly quickly.

“We even ran a few extra copper runs between our wiring closets, just in case something went wrong,” he says.

Still, in some instances, you cannot avoid using fibre. For long-distance links, single-mode fibre is the No. 1 option. While single-mode can cost more than US$300 per drop – twice as much as Cat 5 and US$100 more per drop than single-mode – it offers the greatest distance and better performance, cabling experts say.

“We are seeing more calls for single-mode fibre to be installed in backbones,” says Pat McMurray, LAN specialist and director of network infrastructure for cabling installation firm NetVersant Solutions. “Five years ago, we did maybe 5 per cent of the installs within a building with single-mode in the backbone. Today, I’d say 25 per cent now have single-mode.”

McMurray says most fibre installations in the past were done with multimode fibre, which is less expensive but does not support Gigabit Ethernet over as great a distance as single-mode. He adds that the increased interest in Gigabit Ethernet has boosted installations of single-mode fibre. A price drop of around 20 per cent from last year for Gigabit Ethernet switches (according to IDC) may have something do to with this.

“When you’re starting to get into Gigabit [over distances of 1000 feet], that’s when you want to look at single-mode fibre. When you start getting into campus environments, that’s where you start seeing lots of single-mode,” McMurray says.

New Technologies Save Old Wires

McMurray’s observation on the uptake in single-mode installs is evident at Jackson State University in Jackson, Miss. The school recently spent US$2 million to connect 48 campus buildings with single-mode fibre, and to rewire its buildings with Cat 5e cabling for desktop connections. Michael Robinson, director of network communications, says most of the new fibre is single-mode because he wanted a Gigabit backbone and “because of the wide-area nature of our campus – some of our buildings are a quarter-mile to several miles apart.”

In addition to building a Gigabit backbone to handle its growing Internet traffic, the school’s other goal, according to Michael Robinson, director of network communications at the school, is its installation of 3,700 IP telephones from Alcatel to all students and faculty.

To help offset the hefty bill for rewiring the school, Robinson uses old two-wire phone wiring in the dorms to deliver IP voice without having to deploy expensive IP phones in each room. Robinson is deploying about 1,000 digital phones from Alcatel to the school’s dorms instead of IP-enabled Alcatel phones, which cost about US$200 more per unit. He is running the digital voice over the dorm’s standard phone wiring to wiring closets, where digital-to-IP conversion units from Alcatel convert each digital phone signal to IP.

Another business taking the wire-recycling idea to another level is Starwood Hotels. The firm was looking to provide high-speed network and Internet access to its hotel rooms, but did not want to rewire its entire chain of hotels with Cat 5 cabling. Instead, Starwood partnered with Unisys to install Cisco Long Reach Ethernet (LRE) technology in its hotels.

LRE technology is aimed at service providers looking to deliver high-bandwidth network connections to apartment buildings and office parks. LRE gear runs very-high bit rate DSL signals over the phone lines for reaching network endpoints, then connects back into an IP/Ethernet infrastructure in the backbone.

Starwood so far has installed LRE technology in hotels in Sheraton and Westin hotels in New York and Connecticut. The hotels use Cisco 575 LRE customer premises equipment (CPE) modules – about the size of a cable or DSL modem – which have RJ-45 network ports for client connectivity and provide up to 15Mbps pipes to each room.

Over phone wires, the CPEs in the rooms connect back to a Cisco LRE 48 Plain Old Telephone Service Splitter, where room traffic is aggregated and hooked into a Catalyst 2900 switch. The Catalyst then links an Ethernet backbone and an Internet connection.

According to Kelly Link, a project manager with Unisys who is overseeing the Starwood LRE project, using phone wiring to deliver Ethernet connections to rooms will probably save the hotels 20 per cent in wiring costs while eliminating the disruption of rewiring rooms for Cat 5 cabling.

Category 6 Cabling Not Quite Ready

One cabling technology on the horizon is Category 6 cabling, the next iteration in unshielded twisted pair copper cabling for LANs. The new cabling technology runs its signals at 350MHz, vs. Category 5e, which runs at 200MHz. While the new cabling is supposed to offer more reliable, consistent data rates than its predecessor, the Telecommunications Industry Association, the standards body which governs data and voice wiring specifications, has not yet approved the technology. However, because the standard is not completely set, users could run into problems if all pieces of a wiring infrastructure – from cables to patch panels and connectors – meet Category 6 specifications.

“[Category 6 cabling] has a whole lot of things you have to be careful with,” says Pat McMurray, LAN specialist and director of network infrastructure for cabling installation firm NetVersant Solutions. “It requires more ceiling supports…because the size of the cable is a bit larger, so you’ll have to account for that in the conduits. It is more sensitive to temperature fluctuations,” which can cause degradation in throughput. He says the cable is also susceptible to moisture and condensation, which can cause serious throughput problems when using the cable to run Gigabit connections.

Category 6 technology is still being worked out and is expected to be finished in 2002. McMurray says even still, about 10 per cent of his customers request Category 6 cabling.

“I wouldn’t recommend against [Category 6],” McMurray says, because it does handle Gigabit Ethernet better overall. But, he adds, “I’ve found that most of the time, users bandwidth requirements can be handled with Category 5e.”