How Much Bandwidth is Needed for VoIP Phone Calls?
Posted on Sun, Nov 06, 2011 @ 09:58 AM
Echoes, hollowness, dropped calls, static, hissing, and popping are just a short list of problems that companies can experience if they don't have enough bandwidth when moving to VoIP. Other factors also can affect available and required bandwidth and should be considered during this time. So what does this mean? Let's answer the bandwidth question first.
One VoIP phone call looked at in insolation - which almost never occurs (more on this below) - is about 50 kilobytes per second or kbps. The call itself can actually range from less than 40 kbps up to 200+ kbps depending on the type of IP system you have, the VoIP carrier that you are using, whether you have VoIP or SIP technology, any QOS (Quality of Sevice) parameters that are in place, etc. Confusing, I know.
The simple math . . . is that a single T1 provides users with about 1500 kilobytes per second of bandwidth (also known as megabytes per second or mbps). Divide 1500 kbps by 50 kbps and that means one T1 should be able to handle 30 VoIP calls, right? No. And this is where businesses can quickly make a costly, lengthy, and troublesome mistake.
The real math is . . . other factors can impact bandwidth and should always part of your overall communications strategy. They are numerous and can affect your capabilities, requirements, or both and can be difficult to identify once the process has begun. Some examples are:
- Your VoIP calls are actually closer to 200 Kbps in size instead of 50 kbps (as they are with one major VoIP provider). Your internet connection can now only handle 7 VoIP calls when you had planned on 30.
- An employee streams music or downloads a movie during the business day, maxing out your capacity and leaving little bandwidth for your VoIP phone calls. Clients report choppiness and stuttering and work flow suffers.
- Videoconferencing and conference calls are a part of your day-to-day activities and were not factored in to your bandwidth needs
This is the point where companies usually end up scrambling to buy additional bandwidth which negates most if not all of their expected VoIP savings. In fact, they may end up spending much more than originally planned. Adding bandwidth may also add to the complexity of their communications (not to mention bring another vendor into the equation - which creates its own issues) and unfortunately probably not address the actual issue that is causing their difficulties.
Consider an end-to-end single internet and telephone service provider. Having one "throat-to-choke" for all of your organization's communications - including internet service, phone service, the telephone handset itself, wiring, adding or removing users, routing calls, system changes, etc. - can add substantially to the bottom line. Advanced VoIP technologies such as SIP can also be part of an effective solution.