Collecting a public measure for voice over WLAN gear
By Christine Burns, NetworkWorld.com, 11/01/04
Picture me calling from a VoIP phone on a wireless network, something akin to that annoying Verizon Wireless commercial guy.
Can you hear me now?
Given the buzz about VoIP as the “killer app” for wireless networks, getting to the bottom of that question is the crux of the testing currently going on in Network World Lab Alliance partner David Newman’s lab in southern California.
David is working with VeriWave -- a vendor of wireless LAN test equipment called TestPoints that provides extremely precise delay and jitter measurements. VeriWave has as developed a VoIP test suite especially for this project that hones in on R-value, delay, jitter, frame loss and other metrics critical to voice and data quality. Additionally, we’re using e340 and i640 handsets from SpectraLink, a leading provider of wireless VoIP handsets to generate the calls and Spectralink’s SVP Server to handle call setup and routing.
We’ve got two underlying goals for this test.
First is that we’re collecting the first public test numbers that speak to how these products handle voice traffic in and of itself and how they perform with additional data traffic gets added to the network. Specifically we’ll take measurements in the key areas of voice quality QOS enforcement, and roaming capabilities.
We’ll get at the voice quality measurements using R-value derivations computed from the jitter and delay tests and relating them to more well known – but also more subjective -- Mean Opinion Scores for audio quality. We’re mandating vendors MUST NOT reserve, or “nail up,” bandwidth for the exclusive use of VoIP traffic during these tests. Bandwidth must be available to data traffic when there is no voice traffic. We’ll be testing the roaming features of these products to determine audio quality and failover time for VoIP clients migrating from one access point or switch to another.
You can find the detailed test methodology here.
Our second goal is to test the wireless switch vendors’ claims that their thin architecture is more conducive to supporting voice over WLAN applications than the traditional "fat access points" that currently dominate the enterprise.
We’ll print -- and post -- the results of all of these tests in great detail on Monday, January 10th. If you want to weigh in before then, we’re always listening.
Can you hear me now? Good.
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Comments
I'am VoIP over Satellite researcher, I want to measure a VoIp thus,I need software that lets me to measure the voice delay and its quality of service.
Please inform me if you got any such software.
Regards
Sayid
Posted by: sayid on May 22, 2005 11:06 PM
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