What are the Differences Between TDM vs. VOIP Based Conferencing?

Choosing a conference partner with the right type of network is very important. Some networks utilize a more traditional technology known as TDM (short for time-division multiplex). A strategy of more recent vintage is known as VoIP (short for Voice over Internet Protocol).  While both types of network based conferencing solutions offer certain benefits, one may clearly be the best option for your company.  The only way to know for sure is to take a look at TDM vs VoIP and determine which one fits neatly into your current corporate culture.

Stable Connections

Network redundancy is one of the aspects of TDM that help to make it remain attractive to conference users.  Thanks to safeguards built into the back end of the conference network, disconnects are few and far between.

With VoIP, traditional switches are removed from the formula, with the possible exception of local switches that are used to jump on and off the network at each end.  As long as the Internet connection remains stable, there is an excellent chance that disconnects will not occur.

Overall, in terms of establishing and maintaining connections to conference events, TDM vs VoIP run very close to one another, with factors at the user end having more to do with how well those connections remain in place.

Moderator and Attendee Functions

When evaluating TDM vs. VoIP networks, look closely at the range of functions your organization will need for moderators and others attending the meeting. These functions are typically controlled at the system level (not network), however they typically rely on touch tone commands (commands entered via the phone keypad).  Sometimes, VoIP based systems are not as reliable detecting touch tones because of latency, codec compatibility issues, and aggregation of noise cancellation artifacts implemented at routers.  If touch tones are not reliably detected, systems on VoIP networks will have limited functionality.

Sound Quality

A key element in considering TDM vs. VoIP based conferencing is the sound quality of the audio portion of the meeting. TDM technology improved greatly over the years, virtually eliminating issues such as static, cutting in and out, and the ever popular “voice in a barrel” phenomenon. TDM tends to offer crystal clear sound quality that is hard to beat with any other option.

VoIP does offer credible sound quality, although connection speeds can affect the clarity. Network congestion, bandwidth issues, or otherwise weak connections can mean muffled audio from various trunks connected to the conference. The issue will magnify as the number of connections increase. Lag times due to weaker connections can also chop off some words as the participants speak or cause echo. Finally, without filtering checks and balances, background noise can feed into the audio portion of the meeting and cause a great deal of disruption.

In terms of sound quality, TDM typically has less variability.  VoIP, when implemented well, can also offer high quality audio, but it is more difficult to control the end-to-end solution, so it is not uncommon to experience significant variability in sound quality when using VoIP.

The Cost of TDM vs VoIP

Traditionally, the use of TDM has been over a public switched telephone network (i.e, “PSTN”), with local and long distance carriers providing the framework for the signal transfers. The use of the PSTN to transmit data remains the more costly option, even with today’s more competitive rate packages.

VoIP is a less expensive option. Lower cost is the primary motivation when service providers turn to VoIP, and cost often plays a role in how a provider implements VoIP within their network.  Low cost implementations tend to suffer in quality.  Assuming that you are willing to deal with the often inferior sound quality and potential lag time,a lower rate of a few tenths of a penny can sometimes be obtained.

Only you can determine which type of network will serve your purpose. If cost is the only criteria, VoIP based conferencing may be the solution. If sound quality and consistency are also important, TDM is the way to go.



Related posts