Wide area networks (WANs) play a crucial role in delivering unified communications (UC) throughout distributed...
enterprises, yet many conventional WAN monitoring tools don't provide enough visibility to analyze real-time voice and video as effectively as other applications. WAN managers simply put their trust in quality of service (QoS) and wait until something breaks.
"We do not have visibility into our VoIP traffic at all at this time. [We discover problems when] users ... state that a connection was garbled," said Michael Vassallo, senior network administrator at Somerville, N.J.-based interior design firm Dancker, Sellew and Douglas. "In theory, with QoS enabled [on an MPLS network], there shouldn't be an issue with VoIP. But things like duplex errors within the MPLS network affect all traffic ... [and] the lack of visibility is an issue due to the sensitivity that VoIP traffic has."
Without VoIP visibility in his network monitoring software, Spiceworks, helpdesk tickets about poor call quality are like Vassallo's canary in the coal mine for monitoring the impact of VoIP and UC traffic on the WAN.
"[A complaint about call quality] usually throws a red flag [that] other things are amiss, i.e., duplex errors," he said. "Having a greater insight into real-time monitoring would be a beneficial option."
It's a common challenge for networking pros because most WAN monitoring tool vendors haven't developed features for analyzing real-time UC traffic, according to Zeus Kerravala, senior vice president and distinguished research fellow at Yankee Group. Most tools don't go deeper than mean opinion score (MOS) to analyze the underlying cause of a VoIP problem, and MOS for video conferencing doesn't even exist, he said.
Compound that lack of visibility with the bandwidth limitations on WAN links and unavoidable latency over long distances, and you've got a networking environment ripe for performance problems—with few resources to help troubleshoot them in real time.
"Generally, the user is going to know there's a problem before the IT department does," Kerravala said. "That's going to have a much greater impact [on branch offices] because typically you only have a tenth of the bandwidth on your WAN as you do your LAN."
WAN monitoring vendors start to beef up UC analysis
Although some UC vendors sell or bundle monitoring systems into individual products, they rarely offer a comprehensive picture, Kerravala said. Enterprises are also hesitant to invest in niche WAN monitoring tools that specialize in UC traffic, he said.
"Any large company is not going to spend $10 million on their VoIP system and press the management into something that's virtually a startup," Kerravala said.
However, some recent announcements suggest that conventional WAN monitoring vendors are taking UC more seriously.
NetScout Systems Inc. recently acquired Psytechnics, a niche vendor specializing in monitoring quality of experience metrics—noise, echo, delay, distortion—for voice and video endpoints. NetScout intends to integrate Psytechnics into its products, according to Steve Shalita, vice president of marketing at NetScout.
"MOS was the way things were measured back when everything was TDM, and it's adapted to be used today for IP, but it's not scalable ... or granular enough," Shalita said. "[UC] is really a service-oriented environment."
Streamcore, a WAN monitoring vendor based in France, recently filed patents for its deep packet inspection (DPI) technology to classify and monitor UC traffic into 100 different classes of service for specific UC vendors and applications. The features are due out later this year in the 6.0 release of its software.
I'm not saying there haven't been times when there are too many calls that traverse the WAN circuit, but ... we haven't run into anything from a monitoring standpoint ... where we haven't been able to dig into it [enough].
CIO and Vice President of IT, Michael Baker Corp.
Convergence of real-time UC traffic on IP networks is driving the need for granular WAN monitoring, according to Frédéric Hediard, vice president of product strategy at Streamcore. Not only are IP networks converging; UC endpoints are as well, he said. A single device, such as an IP phone or desktop client, may support voice, video and messaging services, Hediard said.
"In the past, each device was using a different IP address, so you could distinguish whether it was data or video by looking at which IP address or which subnet [the traffic] was coming from," he said. "If you have a UC client on your PC, intelligent IP phone or tablet ... it's all going to come from the same IP address or subnet.... But [with DPI] we can detect if it's Microsoft Lync traffic or if it's Polycom high-definition video conferencing."
Tried and true QoS, WAN monitoring software sufficient for some
Not every WAN manager has a problem with the lack of visibility that conventional WAN monitoring tools have into UC traffic.
The wide area networking team at Michael Baker Corp., a professional services firm based in Moon Township, Penn., uses SolarWinds' Orion software to monitor all WAN traffic, including UC services, according to Jeremy Gill, CIO and vice president of IT.
Network engineers use Orion's reports to design and build a WAN optimized for VoIP, messaging and a moderate amount of video conferencing, he said. The company is running a pilot project for Cisco's Unified Personal Communicator (CUPC) with 80 users across the WAN, and network engineers are watching Orion for any signs that the UC client is straining the amount of available bandwidth at a given branch. Gill has declined to roll out CUPC's desktop video conferencing feature until he and his team understand UC's impact on the WAN.
Gill hasn't felt compelled to invest in third-party UC monitoring tools, saying he maintains VoIP, video and messaging performance by monitoring bandwidth utilization in Orion and using QoS to prioritize UC traffic.
"I'm not saying there haven't been times when there are too many calls that traverse the WAN circuit, but what happens in that case is it goes out over the local PRI and onto the PSTN," he said. "We haven't run into anything from a monitoring standpoint ... where we haven't been able to dig into it [enough]."
Let us know what you think about the story; email: Jessica Scarpati, News Writer.