The Achilles heel of IP telephony, or VoIP, is low quality bandwidth.

We face this often.  As you can imagine, many people who are interested in VoIP are interested in saving money.  That makes sense, as this technology can save a large percentage of monthly outlay on communications cost.  The downside is that sometimes you want to save more than you should save, and thereby create an unmanageable context.  How much savings is too much?  When you don’t have a predictable level of service, you have tried to save too much money.

In a typical hosted PBX scenario with less than 10 phones, often a business-class cable internet connection will create a predictable level of service.  Keep in mind that a good rule of thumb is 100k each way for EACH active voice conversation.  SO, you want to have 5 simultaneous voice conversations?  You will need 500k of upload and download speed, not including your normal DATA usage on your Local Area Network (LAN).  You will want to double this number (1meg upload), at least, for engineering overhead, and also use Quality of Service (QOS) to ensure that your voice traffic has first priority.  Keep in mind, more bandwidth is better.  Also, speed is no substitute for quality.  Watch this closely.

There are tools to test your speeds to see if your internet connection is able to support adding voice, and they are available on the web. (Click this link to run a test on your internet connection.  Test will launch in a new browser window.)

Pay close attention to the upload speed.  This is where the pain normally is.

Once you have checked off that your WAN connection is fast enough, then you can test the quality of the bandwidth, but that is a different blog posting….