Network Infrastructure

Troubleshooting VoIP Problems in the Call Center: How to Get to the Root of the Problem Fast

By TMCnet Special Guest
Vincent Choi, Product Marketing Manager, Visual
  |  March 15, 2013

This article originally appeared in the March 2013 issue of INTERNET TELEPHONY.

Ahh, VoIP – the miracle technology that helps businesses streamline call center operations and deliver better customer support. It’s a dream, right?  So why all the frustration when most of today’s call center equipment and applications have built-in management software and tools to help you see and fix problems?

In this case, the devil is in the details – the granular packet level details to be exact.  With today’s complex deployments, if you can't dive in deep – all the way down to the packet level – you can’t find the root cause. If you can’t find the root cause, there’s a high likelihood you’ll see this problem again and again.

This again-and-again costs you time, money and loads of frustration with your customers and employees.

Without question, the management software and tools most call center equipment and applications offer are key to helping you monitor hardware availability, call center efficiency KPIs, QoS monitoring and real-time event alarming. But these solutions fall short of helping you isolate root cause, as they usually lack the transaction-level granularity to identify the source of VoIP performance or transaction issues between components of the call center infrastructure.

This makes it difficult for you to get at the true source of a network problem and isolate it, which means you might see this problem again.

To get the level of detail you need to find root cause and fix problems for good, a packet capture appliance that gathers data from multiple points on the network, and correlates those data streams in real time, will save you and your organization time and money, while increasing customer satisfaction.

The following are four key VoIP/call center issues you’ve likely encountered already (or will), but were unable to resolve with your standard tools, and some highlights on how a packet capture appliance with real-time statistical analysis can help you solve the issue:

1.      Voice Quality Caused by Poor WAN and Network Performance

When a traditional VoIP monitoring system reports quality issues, it does not provide the source and destination IP address information of the calls that exhibited the issue. As a result, it’s difficult to isolate the network or service provider, so the calls transverse to isolate the issue.

HOW TO FIX IT: Packet capture solutions that analyze and keep detailed call by call source, destination address and ID information (while streaming all packets to disk) allow you to go back in time and review the actual groups of calls that exhibit poor call quality. You can then review the correlating IP network links that exhibit the problem. Actual packets with detailed timing information can be retrieved as proof and given to the network service provider to isolate the root cause, if needed.

2.      Callers Complain of Intermittent Problems

When a user or an agent complains about call issues, it is necessary to identify the specific user traffic flow and isolate it from the other calls. Unfortunately, most users do not typically know their IP address, and to complicate matters, IP addresses often change as they transverse across proxy server/call managers.

HOW TO FIX IT: Packet capture solutions that index packets that belong to a call – based on caller and callee ID – and correlate that information to an IP address, allow you to quickly identify the relevant call (back in time) through smart filtering by call status or user ID. This dramatically reduces the time needed to retrieve all relevant packets and review the transaction details between various system components to identify the root cause of the problem. The call trace with the actual packet(s) can be offered as proof to fix the problem and verify the solution.

3.       Call-Forwarding Issues within the Call Center Systems

Many system components are involved when accurately and quickly routing customer calls to the appropriate operator or application. Some of these transactions involve more than just VoIP signaling protocol, such as SIP, and include complex multi-tier transactions between servers.

To identify the problem, you need to be able to view the grouping of the call that exhibits the forwarding problem in order to narrow down the problem’s scope.

HOW TO FIX IT: Having full visibility of all calls with a full range of statistics is important to isolating call-forwarding issues. If you can’t track it, you can’t find it.  Therefore, using smart filtering that allows the grouping of calls based on a certain range helps narrow down the server involved.

You can, for example, filter by call duration, call complete status, MOS scoring, or caller/callee address range. The packet related to the server can then be retrieved with a context-sensitive retrieval filter to get to the root cause of the problem faster.

4.      Intermittent Issues that Appear after Equipment Firmware or Hardware Upgrades

During system firmware upgrades in the call center, problems may result from bugs in new firmware. Or, hidden issues with other vendor devices can suddenly emerge. Left unaddressed, these issues can escalate into cataclysmic call center events. These types of problems are especially difficult to resolve without packet-level visibility. It is extremely important to have all the packet information available to show to the respective vendors involved, so that the true source of an issue can be identified and the problem resolved.

HOW TO FIX IT: Packet capture solutions allow you to capture transactions between all servers. In addition to the ability to retrieve VoIP call-related packets, other application transaction can be retrieved using application or pattern matching filters. Multi-tier transactions can be merged into a multi-tier transaction view with timing information, making identification and comparing of transaction flaws before and after an upgrade simple. 

The good news is that the technology to quickly isolate root cause is available. 

Stop struggling to isolate your VoIP issues and invest in a packet capture solution with 100 percent stream-to-disk and real-time VoIP KPI analysis. It will give you and your team the level of detail needed to accurately walk through a sequence of events, correlate the data, and solve problems fast. In the end, this will save your organization money, and increase end user and employee satisfaction with the call center.

And, you’ll be a network hero.

Vincent Choi is product marketing manager at Visual, a Fluke Networks brand.

Edited by Braden Becker