Assessing Networks at Granular Levels

 
 
By Caron Carlson  |  Posted 2001-12-05
 
 
 

The network that connects approximately 4,000 users at Lawrence Berkeley National Lab in Berkeley, Calif., to sister sites in Oakland, Calif.; Walnut Creek, Calif.; and Washington is managed by exactly 10 individuals. Because none of them works on the East Coast, the lab relies on remote network analyzers to keep the two coasts connected and running.

The Berkeley Lab, which hosts research primarily in the fields of advanced materials, life sciences and energy, uses a network analysis system called Surveyor, built by Finisar Systems. Because the labs IT professional staff is not available at each site, the team accesses sites remotely for troubleshooting.

"As we grow, we need a proactive way to solve problems," said Mike Bennett, senior network engineer at Berkeley Lab. "We all have remote access, and we all run the Surveyor applications on our laptops. Instead of having to drive 20 minutes to an hour to address a problem, you can just get online at home and start working on it right away."

The lab uses Finisars hardware probes, which reside at remote sites. Called THGs, for "Ten one Hundred Gigabits," the devices allow the lab to integrate sites with the main analysis system in Berkeley. Bennett and his colleagues use the THGs for traffic generation for performance testing and also for protocol analysis. Bennett said he appreciates the hardware-based system because it increases his confidence that packet loss is minimized.

Next week, Finisar will upgrade its monitoring and analysis console, which is built for Ethernet and VOIP (voice-over-IP) networks. The new version, Surveyor 4.1, was developed to make troubleshooting of both local and remote network segments easier.

Surveyor 4.1 includes an optional Multi-QoS plug-in module, which decodes more than 30 major VOIP protocols packet-by-packet. The feature gives IT managers the means to evaluate call quality of VOIP, teleconferencing and other applications. It applies a new call quality scoring tool known as the R Factor, which evaluates call problems such as jitter, packet loss and delay, and then translates the score into the traditional telephony call quality index so that network managers can determine the actual quality experienced by callers. It also incorporates factors such as the timing of the problems during a call.

"When youre an IT person, how do you correlate jitter and delay and packet loss to toll quality?" said Timothy Bean, vice president of engineering at Finisar. "If you had packet loss, it matters whether it was at the beginning of the call, the middle of the call or the end of the call."

The Multi-QoS feature also allows network managers to listen to calls to assess quality directly. The new product is scheduled to ship at the end of the month.

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