With power over Ethernet (POE) becoming a hot issue, you had to figure the test community was getting its input ready.

Ixia (Nasdaq: XXIA) today announced what appears to be the first test card for POE, the recently standardized specification for delivering 48 volts of power across Ethernet lines.

Standardized last summer by the Institute of Electrical and Electronics Engineers Inc. (IEEE) 802.3af task force, POE was considered crucial to the future of voice over IP (VOIP). It was designed to allow IP phones to draw power from the switch the same way old-school telephones do, making the newer phones more palatable to consumers. Vendors have been offering pre-standard POE but are now adding the 802.3af version to their equipment (see Power Over Ethernet Approved and Ethernet Gets the Power).

Ixia's new module, which takes up one slot in the company's 1600T or 400T chassis, emulates the power drain of up to four devices being connected to an Ethernet switch or router. It makes sure the devices get powered up properly, but it also works with a traffic generator to make sure data flow isn't being interrupted. If too many devices draw power from a particular switch or router, the box's data processing capabilities could get hit.

It's similar to plugging too many appliances into a power strip. "At some point, you have your computer on there and it doesn't get enough power to run. Your computer will start acting flaky," says Josh Goldstein, Ixia product line manager. "We've seen this happen in wiring closets. Things will get flaky because there's not enough juice." [Ed. note: In Ixia's home of Southern California, "flaky" is, like, totally a technical term.]

Ixia appears to be the first test company to produce a POE module, which was developed at the behest of equipment vendors' Extreme Networks Inc. (Nasdaq: EXTR) among them. Until now, companies had to devise their own tests.

"They've all been doing homebrewed things," Goldstein says. "They'll actually have 256 IP phones in there, and they'll have a lab tech run around and take all 256 phones off the hook so they draw more power."

Because POE testing has been ad hoc, it's difficult to say how frequently problems occur, Goldstein says. Even if few devices are connected to the switch, potential trouble spots still loom. In Gigabit Ethernet, for example, power and data flows are multiplexed across the same pairs of pins, opening the possibility of interference, he says.

Other POE testers could be on the market soon. Spirent Communications expects to produce a POE product, although the timing is unclear. "Spirent will be making announcements that enable testing this new important technology without forklift upgrades to our customers' existing Ethernet test systems," writes Mark Fishburn, vice president of technical strategy, in an email.

The Ixia POE module should begin shipments within 60 days, Goldstein says.

— Craig "Flaky" Matsumoto, Senior Editor, Light Reading