North American Network Operators Group

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Re: Clearwire May Block VoIP Competitors

  • From: Mikael Abrahamsson
  • Date: Sat Mar 26 14:56:45 2005

On Sat, 26 Mar 2005, Adi Linden wrote:

90kbps may be low bandwidth but the packets per second are a killer for some equipment. VoIP typically has small packets, 80 bytes or 160 bytes, whereas your webbrowser has most packets close to the max MTU, usually 1500 byte packets. There is quite a bit of wireless gear that buckles under the stress of very few VoIP streams. Those few streams add up to much less then the theoretical advertised throughput.
A typical voip call is a packet in each direction every 20ms, this makes a total of 100pps.

Translated into a tcp stream with one ack per data packet, this would mean 600 kilobit/s bandwidth usage with the same pps. I would be quite upset if I couldn't use 600 kilobit/s for approximately the same time I would use voip per day (which truthfully wouldnt be much).

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Mikael Abrahamsson email: [email protected]