* More WLAN noteworthy nuggets
NetWorld+Interop 2004 is poised to take place next week in Las Vegas with a full wireless conference track. I’ll continue to review here a bit of what’s transpired since last year’s N+I show, when many wireless LAN vendors made their debuts.
* Last summer, users gained more flexibility to increase speed and avoid interference in their WLAN designs with the availability of industry-standard 54M bit/sec 802.11g products and additional 5 GHz spectrum made available worldwide for 54M bit/sec 802.11a products.
* The industry is arguing heatedly over the need for physical site surveys.
Some pundits maintain that this exercise is a waste of time and money, given that access points are now relatively inexpensive, and site survey tools from Aruba, Trapeze, and others allow you to automate much of the process.
Then again, these tools aren’t perfect and can’t be expected to account for every circumstance.
Consider the University of Southern California, Los Angeles. It was impossible to WLAN-enable fraternity and sorority houses without a physical site survey, says James Wiedel, director of networking, who oversees the operation of 250 Enterasys access points on campus. This was mainly because the university doesn’t own the buildings, let alone know how they are constructed.
“We don’t know what’s in these walls,” Wiedel says. “You might turn a corner and have no signal. And there are lots of doors with full-length mirrors on the back. Often, you might open the door and get a signal, but close the door and lose the signal.”
* Voice on WLANs has stalled, though interest remains high.
Most enterprises are using WLANs to extend data networks, and this has turned out to be a greater systems integration project than most enterprises anticipated. So many have not gotten around yet to worrying much about voice.
Also, the 802.11e standard for quality of service won’t be approved until late this year. Meantime, most WLAN vendors do support some form of prioritization for voice, many in conjunction with the Spectralink Voice Priority protocol.
On the interoperability side, WLAN switch start-up Legra demonstrated the first IP-to-IP 802.11 phone call among different vendor handsets at the VON show in March. It did so using Cisco WLAN phones and an open-source Session Initiated Protocol (SIP) PBX integrated with a Legra switch.
The start-up ported Linux-based Asterisk PBX software onto its switch and backward-engineered Cisco’s own Skinny Client Control Protocol, which runs between Cisco VoIP handsets and the Cisco CallManager PBX. The Legra switch sat in the middle and bridged calls between Cisco wireless VoIP handsets and SIP handsets procured from pulver.com, the VON shows sponsor that also sells VoIP equipment.
