Problems with VoIP Phone Systems

Customers often ask, “What problems with VoIP phone systems are common?”, when considering a new phone system.  This is a valid question!  In this article, we will cover some of the most common issues you may encounter with a VoIP phone system.

Problems with VoIP Phone Systems

Low Internet Bandwidth

What is bandwidth?  Bandwidth is synonymous with the speed with which data passes through your network, in both directions.  VoIP requires a reasonably fast internet connection in order to send and receive voice data packets that are created.  Therefore, it is important to have a notion of how much bandwidth you have in order to access your ability to benefit from VoIP.  Typically, about 80K of bandwidth for each call is sufficient for a common Codec like G711.  Other codecs vary in their bandwidth needs, so check with your VoIP service provider and test your internet speed to ensure you have what you need.

You can find out if your connection speed is suitable for VoIP telephony by performing an online connection test.

Overloaded Internet Connection

Perhaps you have a good internet connection.  But further suppose that your connection is overloaded at certain times of the day because, for example, dozens of other persons in your office use the internet heavily during peak office hours.  This can overload your internet connection so that you no longer have adequate bandwidth for a VoIP phone call.  The overloaded connection is commonly referred to as saturated.  As above, this condition leads to poor quality.

If you do have the proper amount of bandwidth for your VoIP calls but are still experiencing a bad connection, you may be running other programs or applications that are using up your bandwidth.  A good practice is to  minimize the use of your internet connection for other things other than VoIP whenever you are talking.  But you may also need to resize your internet connection to provide for the actual number in your office who are using the internet simultaneously during peak hours.

Poor Call Quality

Poor VoIP voice quality can be created by jitter or packet loss.  When this happens, you might hear weird sounds, noise, echo, or just momentary silence.

Packet loss literally means that some of the data packets that carry your voice are lost and never arrive.  Jitter is variation in time of arrival of packets.  The codec in your softphone (software that converts between your natural analog voice / audio signal and digital packets, and back) assembles the voice signal from digital packets received, and when the packets have a lot of jitter, the sound is poor, sounding very synthetic or artificial.  Complete gaps in the conversation can be noticed.

Use a VoIP SIP test to check your connection for jitter and packet loss.  Your VoIP service provider can suggest tools that will work for you.

Inability to Connect or Register Your Soft Phone

Sometimes you’ll find that your laptop-based soft phone cannot register with the server from which your VoIP service originates (where your SIP account is hosted).  In this condition, you won’t be able to make or receive calls.  To resolve this, after testing your basic connectivity (cables, wireless connection, software firewalls on your laptop), the next step is to use a firewall test tool to check UDP ports used for VoIP service to see if you are getting through the firewall.  These can include SIP ports like 5060-5160, RTP (voice) on ports 10000-20000, and T.38 ports (FAX) like 4000-4999.  If there’s a blocked port, this is the best approach to identifying it.

Inadequate Equipment

Poor VoIP call quality can be caused by outdated routers, firewalls and cable modems.  If you are experiencing poor call quality, you may need to either reconfigure your network gear, update your router software, or replace your gear with new equipment.  Each network element can be examined on your laptop or VoIP device and the internet to isolate older components that can be updated or replaced.


Problems with VoIP phone systems include security concerns, just as it is with other internet technologies.  The most common security issues with VoIP security are identity theft, denial of service, viruses and malware, spamming, call tampering, and phishing attacks that seek to collect user credentials.  VoIP service providers take many measures to make sure they are not  vulnerable to a number of exploits.  These measures may include: clustered firewalls, intrusion prevision systems, call behavior monitoring algorithms, credit limits, access list, geo limits, call routes and VPN connections.  Despite these precautions, you should report suspicious activity or unusual call traffic to your VoIP service provider immediately.  Most providers have a dedicated security team that can work with you 24 hours a day, 7 days a week.

Why you should choose VoIP

VoIP phone systems are the best choice for business, offering calling features that are essential for customer service, productivity and ideal for employees working on the go.  The move to a VoIP phone system provides generous cost and operational benefits, especially when issues are supported by strong services and security.