Colubris Networks of Waltham, Mass., a company that provides services and equipment for public access and enterprise Wi-Fi, is entering a new arena today by announcing plans to support voice technology.
Specifically, its systems will support quality of service (QoS) prioritization of voice over IP traffic on wireless LAN systems by building in the 802.11e standard’s Wireless Multimedia Enhancements (WME).
The way it’s being built in will allow Colubris customers to keep data segregated, so that voice streams on 802.11e or H.323 connections don’t interfere with each other — or with other information, such as video.
“VoIP is going to translate into voice over Wi-Fi: you can see that coming,” says Carl Blume, director of product marketing at Colubris. He says that quality of service is needed to help prioritize that traffic — not just for voice, but also, say, for prioritizing internal WLAN use over guest use, prioritizing health care monitors over simple file access in a hospital, prioritizing different grades of service offerings from a wireless ISP, etc. “You need to prioritize them all,” he says.
“Previously, the data was all equal, or maybe there was some quality of service for some voice traffic singled out,” Blume says. “Most of the existing infrastructures use QoS by filtering traffic. That’s complex to administer, and processor-intensive. That leads to performance drains.”
The feeling is that with WME support, the performance hit will be minimal. Colubris will leverage the virtual AP (VAP) functions it announced in January to segment different kinds of traffic.
The Colubris solution has a central management system for control and administration of an entire wireless infrastructure, which is made up of intelligent access points in multiple locations connected to WLAN services controllers. The system is meant to be highly scalable, so customers can start small and grow easily.
Recently, the Wi-Fi Alliance began testing systems for early 802.11e support using WMM (Wi-Fi Multimedia), a subset of what will be in the final 802.11e specification for wireless QoS, which won’t be ratified until next year at best. 802.11e will actually break down into two categories, called Enhanced Distributed Channel Access (EDCA, aka WMM, formerly WME) and Hybrid Controlled Channel Access (HCCA, aka WMM-Scheduled Access). The former sees to prioritization of traffic; the latter handles parameterization of traffic, based on reservation. Under ECDA/WMM, traffic doesn’t get guaranteed bandwidth. You can read more about them in this Intel white paper.
