Got VoIP? Then Monitor These Key Network Metrics
How jitter, latency, and packet loss impact VoIP quality of service
June 16, 2015

Patrick Carey
Exoprise

Share this

Chances are you either have already or are contemplating replacing your old POTS/PBX telephone system with some flavor of Voice of IP (VoIP). With so many solutions available, you may even be thinking about going beyond a simple phone system replacement and upgrading to a rich unified communications suite, complete with real-time voice, video, screen sharing, and collaborative document editing.

The good news is that you don’t even need to have a seven-figure IT budget to get all these features. Pay-as-you-go SaaS offerings like Skype for Business, GoToMeeting, join.me, BlueJeans, WebEx and others have put unified communications in reach of every organization. But before you cut the phone cord you need to understand how your network performance (or lack thereof) can make or break your user experience and productivity with these tools.

Quality of Service Metrics for Unified Communications

We’ve all suffered through live meetings or VoIP calls where the audio and/or video was bad. A few extra seconds in a webpage load might go unnoticed but when audio and video is choppy, delayed, or has gaps, it can be excruciating.

To ensure Quality of Service (QoS) for VoIP and unified communications you need monitor and manage three basic network metrics:

Latency – how much time it takes for data packets to get from one designated point to another.

Jitter – the variation in in latency over time.

Packet Loss – the percentage of packets that never reach their intended destination.

Let’s take a quick look at the effects, root causes, and remediation techniques for each metric.

Latency

Ever been on a conference call with somebody in an adjacent office or cubicle? You end up hearing everything they say twice, first directly from them and (hopefully) through your headset or speakers a short time later. That’s latency. There’s always some, but when the round trip latency goes above about 250ms we start to notice it – awkward pauses and people talking over each other. Some latency is out of your control (e.g. for calls that traverse the internet), but you should aim for internal network latency levels of less than 150ms.

Latency problems are usually the result in packet handling and queuing delays; essentially packets get bogged down at your network nodes, either because the network is not configured to expedite delivery of VoIP/UC traffic or there is insufficient bandwidth.

Jitter

Most VoIP/UC solutions employ packet buffers to compensate for some amount of jitter, so it’s often not as easy to detect problems on calls. High jitter rates (i.e. large fluctuations in latency) will often result in dropped packets and gaps and audio/video transmission. In general, you want to have internal network jitter of less than 100ms. Jitter beyond that level will result in additional transmission delay (from the buffer processing) and potentially packet loss. Jitter is also often a sign of networks not configured to prioritize VoIP/UC packets.

Packet Loss

VoIP is highly susceptible to packet loss. Even a 1% packet loss will noticeably affect most real time protocol (RTP) codecs. VoIP/UC clients will recover the best they can but the user experience will be very poor, resulting in lost productivity, aborted calls, and sometimes headsets that are smashed to bits in a fit of rage.

Packet loss is often the a symptom of latency/jitter issues, but is often the result of network misconfigurations, insufficient bandwidth, or simply network equipment that is not up to the task of handling the increased demands of real time communication and collaboration.

Getting Ready for VoIP

To get ahead of these problems, you need to implement a monitoring and remediation plan early, ideally before you deploy these IP communications solution widely. This plan should include the following:

Baseline Testing and Ongoing Monitoring – You can’t fix what you don’t see. It’s a good idea to run some diagnostics/synthetic point-to-point tests within your network to measure baseline latency, jitter, and packet loss metrics so you can see how well your network is configured today. However, it’s also important that you continue to monitor these metrics as you scale your VoIP/UC deployment so you don’t get blindsided as users come online.

Network Configuration Improvements – Your existing network equipment may support higher VoIP QOS but require configuration changes to do so. Configuring to prioritize VoIP traffic will improve both latency and jitter. Bandwidth reservation, policy-based network management, Type of Service, Class of Service, and Multi-Protocol Label Switching (MPLS) are techniques generally used for prioritizing VoIP traffic.

Network Equipment Upgrades – It may be time to replace older and less capable network equipment. High quality VoIP routers will have a significant impact on these issues and are a must if you are using VoIP as a complete replacement to your legacy phone system. In addition you should consider upgrading your internet connection. You’ll be needing more speed and bandwidth going forward.

With a solid monitor, reconfigure, and upgrade plan in place your users will have fewer call problems and you’ll have few mangled headsets to replace.

Patrick Carey is VP Product Management & Marketing at Exoprise.

Patrick leads product management and marketing for Exoprise (www.exoprise.com) a provider of Crowd Powered performance monitoring solutions for enterprise SaaS applications like Office 365, Salesforce.com, Box and others. He has over 20 years of experience delivering software solutions to both enterprises and service providers.
Share this

The Latest

March 04, 2021

User experience is a big deal. For public-facing interfaces, the friction of a bad customer experience can send potential business to your competitors. For IT services delivered within your organization, bad UX is one of the main drivers of shadow IT ...

March 03, 2021

When we talk about accelerated digital transformation, a lot of it is embodied in the move to cloud computing. However, the "journey to cloud" will not be uniform across organizations and industries, says Sendur Sellakumar, Splunk's CPO and SVP of Cloud. The uncertainty of the pandemic means that in 2020, many organizations tried to rein in spending to get some last value out of existing infrastructure investments. Yet some things you can't skimp on ...

March 02, 2021

The Model T automobile was introduced in 1908 ... Within a few years, competitors arrived on the scene including relic names such as Overland, Maxwell, and names that survived like Buick and Dodge. So, what does this have to do with the hybrid cloud market? From a business perspective — a lot ...

March 01, 2021

DevOps Institute announced the launch of the 2021 SRE Survey in collaboration with Catchpoint and VMware Tanzu. The survey will result in a more in-depth understanding of how SRE teams are organized, how they are measured, and a deep dive into specific automation needs within SRE teams ...

February 25, 2021

Organizations use data to fuel their operations, make smart business decisions, improve customer relationships, and much more. Because so much value can be extracted from data its influence is generally positive, but it can also be detrimental to a business experiencing a serious disruption such as a cyberattack, insider threat, or storage platform-specific hack or bug ...

February 24, 2021

Previously siloed IT teams and technologies are converging as enterprises accelerate their modernization efforts in reaction to COVID-19, according to a study by LogicMonitor ...

February 23, 2021

You surf the internet, don't you? While all of us are at home due to Covid lock-down and accepting a new reality, the majority of the work is happening online. IT managers are looking for tools that can track the user digital experience. Executives are reading a report from Gartner or Forrester about some of the best networking monitoring solutions available on the market. Project managers are using Microsoft Teams online to communicate and ensure team members are meeting deliverables on time. Remote employees everywhere use OWA to check their office mails. No matter what, you can be quite sure that everyone is using their favorite browser and search engine for connecting online and accomplish tasks ...

February 22, 2021

With the right solutions, teams can move themselves out of the shadows of error resolution and into the light of innovation. Observability data, drawn from their systems and imbued with context from AI, lets teams automate the issues holding them back. Contextualized data and insights also give them the language to speak to the incremental, product-led approach and the direction to drive key innovations in customer experience improvement. Communicating value becomes a much easier proposition for DevOps practitioners — and they can take their seat at the company table as contributors to value ...

February 18, 2021

Prediction: Successful organizations will blur (or erase) the line between ITOps and DevOps. DevOps has to coexist with traditional IT operations ... So bring a little DevOps to every aspect of IT operations. You don't even have to call it DevOps ...

February 17, 2021

The use of unified communications and collaboration (UC&C) solutions has increased since the start of the pandemic, and this increased use has created challenges for IT teams, according to a survey commissioned by NETSCOUT SYSTEMS ...