VoIP bandwidth requirement

batistuta · Veteran Joined: 29 Jul 2005 Posts: 1384 Location: Aachen

A friend of mine is thinking about getting a 5GB/month limited connection over a 3G wireless broadband provider, and would like to use it for VoIP as well. This includes skype and standard SIP internet telephony.

I'm a bit concerned about how much you can talk with a 5GB limit. I know that VoIP is quite bandwidth cruncher, but I'm not sure about actual numbers. I can estimate a typical codec uses 16kbps, but are there any additional overheads? The point is this: the rate is flat upto 5GB, and then they rip you off (to put it sweetly) with a rate of 0.12 euros/MB. This means, it is forbidden to go beyond the 5GB. How much does VoIP traffic take with a typical codec? How much can she talk per month with this setup?
Thanks

derverstand · Guru Joined: 15 Dec 2005 Posts: 511 Location: /dev/null

Hi, Don't know about what provider you are talking; but all of the ones I know with 5GB limit have also a constraint on VoIP: It is simply blocked. Are you sure the ports are opened? If I may give you an advice: Use the good old telekom; this is the ONLY provider with serious VoIP support.
/BR

ljubo · Posted: Tue Feb 06, 2007 8:28 pm Post subject:

With Ekiga you can choose among various codecs, and in that way you can tune your quality/bandwith ratio.
I have these codecs listed in Ekiga:

batistuta · Veteran Joined: 29 Jul 2005 Posts: 1384 Location: Aachen

thank you guys for your responses. I've been doing some research, and it looks like the overhead from the headers comes at about another 8kbps, so in total we are talking at 16-24 kbps. This might be reduced with silence detection, etc.

The provide in particular that I'm talking about is Vodafone from Ireland. Their website sucks so much, it is unbelievable. You have no idea how much you pay in total, they don't mention if the 1.5 Gbps speed is for download, upload, or both, or whether the 5GB limit is only for download traffic or for both directions, the terms and conditions are fuzzy as the German tax system, I mean... at this point I've just recommended my friend to stay away from that company and choose one that shows its customers what they are offering.

I find it strange that providers would block VoIP in a general way, with so many people using skype nowadays. But I guess deverstand you are talking about VoIP as in the standard SIP protocol.

derverstand · Guru Joined: 15 Dec 2005 Posts: 511 Location: /dev/null

Yes. Only SIP is sure. But the rest may follow; if you read the terms of user carefully there are a lot of backdoors for blocking skype or whatever later :/ Therefor my choice is telekom. "All provivers suck; Telekom sucks less" (adapted from mutt.org

/BR