While it doesn’t happen often, every once in a while you’ll come across an IP phone that simply won’t cooperate. You may have gone through every troubleshooting procedure that you can think of, but the phone continues to refuse to function correctly. You begin to consider the possibility of a defective phone, but before you invoke the manufacturer’s warranty, you want to be sure. Here we review the steps you can take to confirm, to a reasonably high degree, that the problem is indeed a defective device.

If you are a voice network engineer, then it has probably happened to you. Your SIP server is all set up and you have plugged in your IP phone. Its lights come on, its screen is activated, you see the loading icon rotating, and then… nothing. For some reason, the phone will not register.

IP phone registration issues are, unfortunately, not uncommon. In this article, we examine the most common causes of registration failures, and best practices for troubleshooting and resolving them.

Wouldn’t it be great to have superhero X-ray vision that allows you to understand, in a single glance, what is going on with the voice traffic on your network? In fact, it is possible to do so using the Simple Network Management Protocol (SNMP). In this article, we take a look at this protocol and highlight the special features it has up its sleeve to help you with your VoIP monitoring needs.

One of the best methods for troubleshooting problems on the network to pinpoint the cause of poor voice quality or a disruption of VoIP services is to capture voice packets in real time and store them so we can analyze them later. When people call TeleDynamics tech support, we sometimes ask them to show us their packet capture files so we can help identify the issue. In this article, we examine practical methods for capturing voice packets at various locations within the network.

One of the most challenging problems that you may face as a voice engineer is dealing with poor voice quality on VoIP systems. It’s often much easier to deal with problems where something stops working completely, rather than trying to resolve an intermittent fault such as bad voice quality.

Many things can cause poor voice quality, and the methodology to investigate those causes is not always readily clear. In this article, we’ll share some tips on where to start and what to do, so that you can quickly identify and diagnose the problem.

A firewall is a vital component of any enterprise network. But, it can also wreak havoc on the operation of VoIP implementations. In this article, we address the most common problems a firewall can introduce to an IP telephony network, as well as best practices for avoiding or remedying them.

How to deal with jitter, packet loss, latency and signaling delay

Some of the most difficult issues to troubleshoot on a network are failures resulting in a degradation of service, a slowdown in speed, or intermittent connectivity, as opposed to a complete disruption in service.

When it comes to troubleshooting issues involving VoIP, this becomes even more acute. Intermittent, low-quality, and metallic-sounding voice, as well as erratic connectivity between VoIP end devices, are all network problems falling into this difficult-to-diagnose category.

Almost all such malfunctions are due to a faulty implementation (or lack thereof) of quality of service mechanisms. In this article, we will look at some of the most common failures of this type, what they sound like, and what should be done to verify and rectify the problems.

If you’re on the voice side of the telecommunications industry, it is inevitable that you will be dealing with data networking. As Voice over IP (VoIP) technologies are overtaking more traditional telephony systems such as ISDN and analog, the voice engineer is required to know data networking fundamentals in order to implement, maintain and troubleshoot modern voice systems.

Back in 1999, when VoIP was still in its infancy, Industry Expert Bruce Robertson told students in the Sheridan College Telecommunications Management post graduate program, “If you go into the telecom industry on the data side, you will probably stay on the data side for all of your career. If you go in on the voice side of things, you will inevitably become involved with the data side, as well.”

This statement has certainly borne true. So, if you’re an expert in ISDN, SS7 or other conventional telephony technologies, it’s essential to also be familiar with data networking fundamentals to remain competitive and relevant in the telecom industry. In this article we look at a nifty tool called a packet sniffer that can be used for troubleshooting many types of VoIP problems and should be in the toolbox of any telephone installer.

Unlike conventional telephony infrastructure, which was developed and tailored to be used exclusively for voice, today’s telecom networks accommodate a multitude of different data traffic types, of which VoIP is just one of many. Because of this, it can be challenging to adapt a network to accommodate voice.

One of the most common challenges involves a technology called Network Address Translation (NAT), which for data networks has been a godsend, but if not configured carefully, could cause problems for voice applications. In particular, NAT is a common cause of one-way and no-way audio on VoIP calls.

In this article, we dive into how NAT can impair voice sessions, cite some common symptoms that indicate NAT may be at the root of your call audio problems, and address how to resolve the issues. 

How to troubleshoot problems arising from blocked ports, ACLs, firewalls, NAT, and more

For networking professionals, one of the most difficult things to deal with is troubleshooting VoIP issues, because the troubleshooting process for VoIP is not always intuitive. Answers to the questions, “What could be wrong?” and “What should I check first?” are not always readily apparent.

To aid your troubleshooting and allow you to take some meaningful actions before reaching out to your telco or vendor help desk, we’ve listed the most common VoIP problems you may face, as well as their causes and solutions.