Emerging technologies update

PCI Express and 802.11g appear to be speeding toward success in the enterprise, while power over Ethernet is making steady progress in selected situations. But it's been slow going for Bluetooth.

PCI Express was designed to eliminate I/O bottlenecks for everything from video graphics to 10Gbit/sec. Ethernet adapters. 802.11g offered a backward-compatible way for enterprises to upgrade their 802.11b wireless LANs to higher speeds. Power over Ethernet would eliminate the need to use AC power for WLAN access points, IP phones and other equipment. Bluetooth promised to end cabling clutter on the desktop.

Computerworld has covered the introduction of each of these emerging technologies over the past two years. In that time, some have gained ground; others have fallen short. Here's a report card on where each stands.

PCI Express: Adding Fast Lanes

After more than a year of slow, steady progress, PCI Express, a new I/O technology designed to replace the Peripheral Component Interconnect expansion bus used in PCs and servers, is ready to roll. Intel Corp. released the first PCI Express motherboard and chip sets this past summer, systems began shipping in August, and a few adapters are now available.

Developed through the PCI Special Interest Group, PCI Express (also called PCIe) replaces the PCI bus with a serial architecture that uses up to 16 sets of wires, or "lanes," to support bandwidth ranging from 500MB/sec. to 16GB/sec. For the most part, PCI Express is designed to solve I/O bottlenecks that most users have yet to experience, but IBM, Hewlett-Packard Co. and Dell Inc. have all rolled out servers that include both traditional PCI and two or more "4x" (four-lane) PCI Express slots to stay ahead of user demand.

On commodity servers, PCI Express appears to have won a battle with PCI-X 2.0, a competing 2GB/sec. standard once supported by HP. "Ethernet and storage-controller vendors started flipping from PCI-X 2.0 over to PCI Express, so we're moving with the market," says Colin Lacey, director of market strategy for the ProLiant server line at HP.

But PCI-X 2.0 will arrive on high-end servers next year, both because PCI Express isn't fully mature and PCI-X 2.0 is likely to be available sooner than comparable 8x implementations of PCI Express, says Tom Bradicich, chief technology officer for IBM's xSeries and BladeCenter servers. Eventually, even these systems will migrate to PCI Express, he says.

PCI Express is already replacing the accelerated graphics port for high-end graphics on PCs. For most other I/O needs, however, PCI Express is overkill. On servers, early PCI Express adapters focus on technologies likely to max out current 1GB/sec. PCI-X bus, including 10 Gigabit Ethernet, RAID controllers and Fibre Channel. But server buyers should be cautious, says Nathan Brookwood, an analyst at Insight 64 in Saratoga, Calif. "As long as they are not finding PCI-X to be a bottleneck, it's still a preferred solution because it's tried and proven," he says.

PCI-SIG is also working on a server I/O module specification that Tony Pierce, the group's chairman, describes as "an external, hot-pluggable form factor designed specifically for servers." And a revised specification, due to be published in 2005, will double the current data rate. For now, however, PCI Express slots are likely to creep into servers in increments. "The transition has begun," Brookwood says. But he doesn't see it taking off in a big way until at least 2007.

802.11g: One Step Ahead

The 802.11g 54Mbit/sec. WLAN specification was designed to provide an upgrade path for 11Mbit/sec. 802.11b networks. While it has sold well in the consumer market, businesses have largely stayed with the slower but more established 802.11b.

802.11g delivered what the 54Mbit/sec. 802.11a standard couldn't: backward compatibility for 802.11b users. But many business simply haven't needed the extra bandwidth, says Ken Dulaney, an analyst at Gartner Inc.

As the technology has matured, however, vendors of enterprise-class WLAN products have replaced b-mode-only access points (AP) with g-mode units, and some businesses are taking advantage of the faster operating mode. Embarcadero Systems Corp. is installing 802.11g in all new sites, says John Montgomery, vice president and chief technology officer. And new applications at the Alameda, Calif.-based company's container shipping terminals require more bandwidth, so he's investigating upgrades for b-mode APs as well. While 802.11a's shorter range would have required adding more APs for the same coverage area, with 802.11g, Montgomery says, he should be able to upgrade just the existing b units. "We are trying to do a one-to-one swap," he says.

As bandwidth needs climb, the long-ignored 802.11a is starting to garner interest as well, says Graham Melville, director of product marketing at Symbol Technologies Inc. It runs in the less-crowded 5-GHz spectrum, and with 11 channels to 802.11g's three, 802.11a APs can be placed closer together without interference. That means 802.11a can support more users at a higher aggregate bandwidth. Melville says the technology is ideal for crowded offices, where power users rely on wireless as their primary connection into the company network.

An even faster variant is on the way: 802.11n is expected to quadruple current WLAN speeds. But the specification is in the early stages of development, and mature products are unlikely to arrive before 2007. Says Dulaney, "If you want higher speeds, go to 802.11a, since there is a lot more capacity at 5 GHz."

PoE: Ethernet Powers Up

Who needs an outlet? Driven by the need to cost-effectively power IP phones and WLAN APs, power over Ethernet (PoE) has quietly moved into the mainstream since the IEEE 802.3af standard was ratified in 2003. PoE is now a global standard for supplying low-voltage power to networked devices by way of Ethernet cabling. "Almost every enterprise I talk to is looking at putting PoE in their wiring closet," says Zeus Kerravala, an analyst at The Yankee Group in Boston.

But that doesn't mean PoE is going in across the board. While virtually all wireless APs and IP phones now can support Ethernet power, PoE is offered only in high-end switches—about 20% of those on the market—and they sell at a 15% to 40% premium, says Rachna Ahlawat, a Gartner analyst. But she expects the premium to disappear over the next few quarters as PoE becomes a "checklist item" for all switches.

Only 14% of all 10/100 Mbit/sec. Ethernet ports shipped with PoE in the first half of 2004, says Ahlawat. And with businesses now keeping existing switches longer—up to seven years—many companies may hold off on adding PoE for a few years or choose to add midspan devices that can send power to selected ports without replacing the switch. Nonetheless, IDC predicts that about 41% of all Ethernet port shipments will be PoE-enabled by 2008.

Embarcadero uses PoE switches to support IP phones. "We're still using traditional methods to power our network switches and WLAN access points," says Montgomery. But he's considering PoE to support new AP and closed-circuit television camera deployments.

PoE is slowly gathering momentum, says IDC analyst Maximilian Flisi. "It will be a gradual, steady phase-in," he says.

Bluetooth: Peripheral Player

Bluetooth promised to eliminate cable clutter by connecting devices ranging from handhelds to printers over a low-power, 1Mbit/sec. wireless personal-area network (PAN). While Bluetooth has made inroads with consumers, it has failed to catch on in the enterprise.

Shipments of Bluetooth-enabled products have passed 3 million units per week, according to Bluetooth SIG Inc., but many of them are cell phones that are sold in Europe. Bluetooth is used in handheld computers, in some cordless headsets and hands-free cell phone kits, and for some specialized purposes. For example, United Parcel Service Inc.'s truck drivers use the technology to allow handheld computers that are environmentally sealed against moisture and have no physical external connection to connect wirelessly to printers. But overall, it has faltered as a cable replacement technology.

Acceptance of Bluetooth has also been slowed because of concerns about interoperability and security. Bluetooth SIG offers interoperability testing, but users still must rely on its product matrices to ensure that different devices have profiles that will work together. "I call Bluetooth a failure because it doesn't deliver ease of use," says Gartner's Dulaney.

Mike Foley, executive and technical director of Bluetooth SIG, says improvements are on the way. The specification will support 3Mbit/sec. by the end of the year, and it will include security features to close some well-publicized vulnerabilities, enhance interoperability and improve power management. It will also support quality of service and multicasting to improve communications with multiple Bluetooth devices .

Today, however, Bluetooth remains essentially a consumer technology. It also faces competition from the emerging ultrawideband 100Mbit/sec. PAN specification. Ultimately, UWB could replace Bluetooth, says Roger Kay, an IDC analyst. "If UWB is capable of sending large amounts of data rapidly over short distances, there is no reason why it can't send small amounts of data as well."

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The same but different: HP's ML 350 series servers combine four traditional PCI-X slots (white slots in photo) and two 4x PCI Express slots (top, in black). While the slots look similar, the 4x PCIe slots, at 2GB/sec., deliver about twice the bandwidth. HP's DL series servers support PCIe by way of an optional PCIe
The same but different: HP’s ML 350 series servers combine four traditional PCI-X slots (white slots in photo) and two 4x PCI Express slots (top, in black). While the slots look similar, the 4x PCIe slots, at 2GB/sec., deliver about twice the bandwidth. HP’s DL series servers support PCIe by way of an optional PCIe “riser card” adapter. Other server vendors offer similar configurations.
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Worldwide LAN and PoE Switch Ports

LAN
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225.75M
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327.84M
PoE
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23.95M
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134.36M

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2004

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2008

NOTES: Ports counted include both 802.3af and proprietary standards; data considers only embedded (end-span) PoE, not midspan devices.

Source: IDC, May 2004

Copyright © 2004 IDG Communications, Inc.

  
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