Speed necessary for VOIP

The problem is not speed but latency.

Most IP Providers says they do not work with Satellite conection.

The latency issue is what i wonder about. The one satellite system that requires you to be stationary and other work while moving. Supposedly the stationary will do voip. hmmm.

Actually there are a variety of issues to look at, and successful use of VoIP is going to depend not just on bandwidth. Another issue is - what quality are you expecting .. is intelligibility the only concern or do you want toll quality?

VoIP can operate over relatively low speed connections (say 128k) however quality will fall apart if there is ANY data traffic sharing the link. If any data is sharing the link then it would be desirable to use higher speeds - say 300k upwards.

Delay can be significant however in many cases the user can tolerate quite long delays. For highly interactive discussions then one way delays of 100mS or so can become noticeable however for more general chatting delays of 300-400mS are tolerable. Obviously some satellite connections can introduce longer delays and this would be intrusive. More info on the

Alan

Our wide acceptance of cellular phones and their often times marginal connection quality (with surprisingly few complaints) I think has shown, at least for personal use, that the desire for cheap & convenience far outweighs any desire for quality. Of course business/professional use is a whole other matter. I might be willing to talk to a salesperson over a marginal cell phone connection to give them driving directions to my place of business, but when I call them to do business with them, that connection had better be "toll quality".

This is largely true although with G.729 compression the bandwidth requirements of VOIP are far less. Of course with compression, quality suffers and we're back to our proverbial "celluar-grade" connection again.

With VOIP a little packet latency can usually be tolerated, while packet loss and packet sequencing problems cannot. I.E., there's no way to "resend a lost word or syllable" and have it still make sense when it finally gets to the other end. This is why successful "toll quality" VOIP implementations must include some type of QOS (Quality Of Service) either

VOIP over the public Internet can sometimes yield "acceptable" results so long as the voice call never encounters any congested paths. Once it encounters a bottleneck, anywhere along the way, call quality will suffer. Over severely congested paths a VOIP call will become unintelligible gibberish.

Mitel Lurker wrote: ....

I have VoIP over cable - does that necessarily go "over the public internet" or are there other choices?

If you mean you have cablemodem/DSL service, yes, that's the "public internet". The only other choice is a private, dedicated WAN (wide area network) which many large companies have. Very expensive, but extremely efficient.