Clearwire May Block VoIP Competitors

Sat Mar 26 19:55:42 UTC 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).

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se