* Aruba is the top dog if you want to add voice traffic to an enterprise wireless LAN
Voice over wireless LAN
By David Newman
VoIP should be an easy fit for wireless LANs, but mixing the two technologies today is difficult. Despite VoIP’s low-bandwidth profile, even a small amount of data traffic on the same network can lead to seriously degraded audio quality and dropped calls, even with QoS features enabled.
That’s the major conclusion of our first-ever assessment of VoIP capability in WLAN systems. Over the course of three months we tested WLAN switches and access points from Aruba Wireless Networks, Chantry Networks (now Siemens), Cisco and Colubris Networks in terms of audio quality, QoS enforcement, roaming capabilities, and system features. Other vendors, including Airespace, Meru Networks and Trapeze Networks, declined to participate.
Among our major findings:
• With QoS enforcement enabled, the products delivered near-toll-quality audio, provided only voice traffic is active. This is fine as long as the wireless network carries voice traffic only, but that’s not likely as companies move toward converged voice-data networks.
• When voice traffic had to contend for bandwidth (even with a little data traffic), dropped calls were common and audio quality on the remaining calls was poor in many cases – and this was with QoS enforcement enabled.
• With data traffic present, roaming from one access point to another took anywhere from 0.5 to 10 seconds – in cases where roaming succeeded at all. These long delays and dropped calls made roaming practically impossible with some vendors’ gear.
While some products struggled mightily in our tests, Aruba’s A2400 and A800 switches and A61 access points were consistently strong performers. The Aruba products posted generally excellent numbers, regardless of how much voice or data traffic was thrown at them. Aruba’s gear just worked, earning it the Clear Choice Award.
For the full review, please go to:
