New Tools Help to Keep VoIP Healthy

Management software can protect IP Telephony against the many ailments of a data network Smoothing the initial replacement of legacy PBXs with IP telephony systems is still the top priority for vendors, system integrators and their customers. On the vendor side of these projects, technicians are gaining valuable experience with each installation. Many large-enterprise IT shops also are building project and product expertise as they work through staged deployments. But mainstream enterprise customers who think they will learn a lot from the early adopters’ high-profile projects are likely to be disappointed. The marquee value of these installations seems almost certain to confine the lessons learned to Project Management 101: Negotiate carefully; plan the work and work the plan; involve all the stakeholders; document everything. Nor are the early adopters and their vendors likely to publicize any difficulties that might crop up.Of course, it’s another project management maxim that any well-planned system conversion, after rolling smoothly through the cutover and acceptance phase, will almost surely still be humming along happily on Day 2—the day the customer takes over responsibility for the installation. VoIP should be no different, right? Right, as far as it goes: Everything could run just fine until, say, Day 20, when an automatic update changes some settings on a server; or Day 52, when someone tweaks the queues on the edge routers in support of the customer self-service application; or Day 137, when some of the LAN switches get a new software load. None of these updates and tweaks and loads have anything directly to do with the IP telephony system, but on a converged network anything that changes the underlying LAN/WAN infrastructure, as well as the network behaviour of any other devices and applications, can also affect VoIP performance. The primary challenge of convergence will be maintaining the quality and consistency of voice telephony in an ever-changing network environment. Monitoring ToolsHelping enterprise customers meet this challenge is the aim of more than 20 vendors of VoIP monitoring and diagnostic tools. These products vary widely in form factor and price, ranging from inexpensive, portable packet analyzers to costly, but comprehensive software suites with probes, consoles and report generators. Some have been developed specifically for IP telephony or converged networks by startups and entrepreneurs, while others come from the current vendors of test equipment and performance monitoring systems for enterprise LANs, WANs, networked applications and carrier networks. In December 2004, we asked as many of these vendors as we could find to respond to emailed questions about the capabilities of their products, and to tell us how well they think enterprise customers will handle ongoing VoIP performance management. The brief product comparison in the table and the discussion that follows aim to put these management tools in a meaningful but general perspective. Depending on the size and complexity of their IP telephony deployments and converged networks, some enterprise customers will be able to manage ongoing network changes via strong communication among the IT staff and by using the LAN, WAN and application management tools they already have, plus the Quality of Service (QoS) and other management capabilities that come with their IP telephony systems. Other users will outsource ongoing management, but there will be many who want to monitor, troubleshoot and control their IP telephony systems themselves, and they will want the right tools for the job. Assess ThisMost of the VoIP tool vendors who participated in our roundup claim that their products help customers with three VoIP-related tasks: assessment, performance monitoring and troubleshooting. Several pointed to Gartner statistics indicating that 85% of data networks aren’t ready for VoIP, and a 50/50 chance of failure awaits those who proceed without a network assessment. Numbers like that underscore the fact that data applications frequently run just fine on LANs and WANs that couldn’t possibly handle VoIP."Most LANs evolved gradually along with the applications and the LAN tools," explained Empirix CTO Jeff Fried in an email exchange. Pre-testing the infrastructure with simulated VoIP calls and other tests "allows IT staff to ensure proper performance ahead of time," according to Fried. Empirix makes the Hammer FX-IP simulator and Call Analyzer, in addition to call center, carrier and other types of test and monitoring products. DiagnosticsIrfhan Rajani, president and CEO of Apparent Networks, concurs on the value of pre-installation assessment as well as ongoing management. Unlike Empirix—and assessment tools from Integrated Research, NetIQ, Spirent, Viola and others—Apparent’s AppareNet software doesn’t simulate VoIP traffic to stress-test networks. Instead, Rajani wrote, "AppareNet diagnoses every IP component of every network. It reports what is wrong, in the form of symptoms (e.g. excessive packet loss or jitter), exactly where the fault is located, and how to fix it."While enterprise customers may be thinking of assessment primarily in terms of determining whether their premises LAN infrastructures and WAN links will support IP telephony deployments, two university contacts told us that they assess or "shoot" network paths to determine their suitability in advance for intercontinental IP video conferences. AppareNet customer Walt Magnussen, director for telecommunications at Texas A&M University, and Brix customer Fred Nay, director, university computing services at Ball State University (Muncie, Indiana) both noted that the troubles they find are most commonly in the local access or premises networks; Internet backbone links are rarely congested. To VoIP product developers, and carriers who plan to deploy hosted or managed IP telephony offerings, assessment means stress-testing VoIP products, not networks. Tools from vendors like Ixia, Candela Technologies and Spirent primarily target these customers, although Spirent also offers a one-week VoIP readiness assessment of two to four corporate sites with its Abacus product for US$30,000.For the majority of enterprise customers, however, assessment tools will be useful to discover where the network needs to be upgraded to deliver the low packet loss, QoS and queuing that will support IP telephony. After the cutover and acceptance, however, monitoring tools will be needed to help keep network-affecting changes from hurting VoIP performance. What, Me Monitor?The technical reasons for monitoring VoIP installations are simple: Occasional packet loss is just a fact of life in IP/Ethernet networks, and a loss rate as low as 1% can cause VoIP packet delay and jitter (variation in delay) which, in turn, play havoc with voice quality. Meanwhile, enterprise data devices and applications will still be ticking along. In fact, multiple data applications can and do share LANs and WANs that drop 2% or 3% of packets, without end users complaining or business processes hiccupping. No wonder data network managers are worried about the addition of IP telephony traffic to "their" networks. Jeff Carpenter, VoIP solutions manager at NetScout, believes, as do many advocates of application performance management and Policy-Based Network Management, that "all converged traffic should be evaluated for appropriate QoS classification. Every application must be prioritized, and then the full mix of data and voice can be monitored for continued performance." Other full-blown monitoring solutions that make a point of covering VoIP include products from Brix, InfoVista and NetIQ. Most enterprise customers have, so far, shied away from the top-down commitment to thorough analysis and centralized decision making that application performance management and Policy-Based Network Management require, but VoIP might provide the necessary impetus, according to Bruno Zerbib, InfoVista’s product manager, IP telephony solutions. "Enterprise customers who embrace a top-down, service-oriented paradigm for managing IP telephony performance will have a better chance of success," he wrote. Zerbib may be right, but it is hard to imagine many enterprises willing to "visualize and navigate through the performance of thousands of contributing infrastructure elements that affect the end-to-end IPT service delivery chain." If monitoring must be that frequent and that detailed in order to be effective, some users will surely go looking for a service provider instead of a product. That’s where companies like NetSolve (now owned by Cisco) come in. Polling DataEvery 90 seconds, NetSolve polls every device in the frame relay networks and Cisco IP telephony installations that it manages from its Network Operations Centre in Austin, Texas. "Something is always changing on networks that can impact traffic," said Renaye Thornborrow, NetSolve senior product marketing manager, "whether it’s applications, devices, sites, circuit or system turn-ups, whatever. That’s why it is so important to continually monitor what’s going on." The company uses homegrown software to make sense of the polling data it collects. More than 90% of the troubles NetSolve detects are resolved remotely, and nearly all the rest are completely diagnosed before a field technician goes to the site, said Gene Boyd, Avnet enterprise services manager, managed services program. Avnet subcontracts with the NetSolve Network Operations Centre to support its portfolio of lifecycle managed services for Cisco-IP telephony installations. Enterprises that don’t want to go to such lengths might instead consider VoIP monitoring products that alert technicians or set off alarms only when particular, user-set thresholds are met, summarizing ongoing performance data in simplified "dashboard" displays or reports. Examples include products from Acterna, Clearsight, Network Instruments, Qovia and SyncVoice. The latter two, along with Apparent, also offer hosted or software-as-a-service products. Network Instruments customer Mark Giorgis, senior network administrator with Long Beach Transit, checks the output from his Network Instruments Observer every morning, looking for anomalies in his 250-station, three-site VoIP installation. "I watch the trend," he said. "I know what is going on, what the normal ranges are, because I see it every morning." Giorgis says he is looking forward to using Observer on the WiMax video safety network being planned. "Once WiMax is deployed, our dispatch can monitor everything that is happening on the buses and, hopefully, we will also provide Internet for our customers." There Will Be a TestCustomers who choose not to monitor performance may want to at least augment their existing LAN and WAN toolkits with VoIP test modules. These add-ons typically test VoIP signaling protocols and measure VoIP call quality in terms of Mean Opinion Scores or other metrics. Some also can record and play back VoIP calls for further analysis. Fluke, Network General and WildPackets are among the vendors offering VoIP add-ons to their existing data network test and analysis tools. Although these and other test-tool vendors offer alarm and threshold setting options, they are more focused on the troubleshooting capabilities they believe customers will need. Jim Vale, voice product manager for Network General’s Sniffer, expects customers will have an easier time coming to grips with onsite than with wide-area VoIP. "In IP-PBX campus networks," he responded, "the art of managing VoIP will be refined as the scale of deployment increases and the lifecycle of the packet voice application is better understood. However, VoIP WAN implementations—particularly those that span geographic distances—will remain a significant challenge to deploy and to maintain quality VoIP service." In contrast, Gary Meyer, Actema’s product marketing manager, data analyzer business unit, thinks that lower-level field personnel will need a simplified VoIP test tool, like Acterna’s handheld HST-3000, so they can interact more effectively with data-trained engineers and tech support specialists, especially as VoIP-over-broadband adoption accelerates. ConclusionAt the moment, there are as many choices for test and monitoring tools as there are for IP telephony systems. But the ranks will thin as enterprise customers pick the winners and IP telephony moves from the early adopter to the mainstream enterprise deployment phase. Will VoIP performance monitoring turn out to be mandatory? Will top-down, network-wide policies finally come into vogue? Or will business as usual prevail: on-the-job cross-training of voice and data staffers, crash courses on the IP telephony console and just-in-time VoIP additions to basic packet analyzers? VoIP technology should continue to evolve, according to SyncVoice president Kerry Shih, until it eventually becomes more reliable and easier to manage. "Reliable quality depends on monitoring in the short run, and VoIP protocols are still changing," he wrote. "Long term, however, I think VoIP systems will be much easier to install and manage and will be a standard rack-mount item in most server rooms." In the meantime, VoIP assessment, monitoring and troubleshooting are important tasks, but whether they warrant automation and, if so, how many thousands of dollars to spend on tools, are open questions. Sandra Borthick (sborthick@bcr.com) is senior editor of Business Communications Review (www.bcr.com). This article is reprinted by permission of BCR. VoIP Management Product CapabilitiesVendorRecord and play back voice calls?Pinpoint cause of failed calls?Generate traffic or simulate calls?Generate reports?Other functions?ActernaYYNYDSL, cable modem, and IP video test capabilityApparentNYNY Brix NetworksNYYYIP video test and per-call IP path infoCandela TechnologiesNYYY ClarusNYIP+PSTNPlanned"Active" testing controls phones in test callsClearsightYNNYAlso monitors other applicationsEmpirixYYYYOther products test and monitor call centres and carriersFlukeYYNY InfoVistaNYNYAlso manages unified messagingIntegrated ResearchNYYYOther products manage Cisco CCM and Unity ExpressIxiaNNYYAlso simulates PSTN and fax callsNetIQNYYYAlso manages underlying Windows serversNetScoutYYYYPart of overall app and network performance solutionNetwork GeneralNYNY Network InstrumentsNYNVia WebAlso tests Gig-E, wireless, IP videoQoviaNYNYAlso monitors UPS and server resourcesSyncVoiceYYNYCreates audit trail of all IP devices, apps; monitors TDM voiceSpirentNNYYAlso tests TDM voiceViolaNYYYAlso can test IP path qualityWildPacketsYYYYOther modules test Gig, WAN and 802.11

New Tools Help to Keep VoIP Healthy

News | 05/26/2005 4:00 am EDT

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