Re: [cobalt-users] Speed/bandwith calcul

[flash22@xxxxxxx]

On Thu, 17 May 2001, satan wrote:

>  Hello all,
> 
> We have a burstable T1 (T1 - T3) here and i m trying to calcul the bandwidth
> 
> I know a T1 is 1.540 Mbps, i also think it is divided into 64 k/sec channel
> (24 i think).

hmm, first, be aware the designation 'T1' is somewhat misused, the 'T'
stands for telephone ;)

The number of channels per trunk is only meaningfull if you are planning
to call your machine on the phone ;) , data provisioning is whatever the
upstream feels like allocating...

Also, the clock rate is 1.544 not 1.540 ;)

Other than that, the overhead is small enough that you can just divide
bits by 8 and gets bytes / second , eg 1544000/8 = 193K/s

for maximum bytes per month you have to do some math ;)

days*hours*minutes*seconds*kbytes
30*24*60*60*193000 = 500,256,000,000 bytes/month (500 gig)

That's your therotical maximum limit for what you can squeeze through a
link at that speed..., actual will be somewhat less.

The other issue you have to deal with tho, is some 'burstable' connections
have shorter periods of integration, eg, sending at T3 speeds for an hour
might get you a surcharge even if you don't exceed some limit over the
total month, you need to make sure you read the contract ;)

> Like on some web site i see 1 gig/month transfer, how do i limit the
> bandwith on my cobalt that is in KB/SEC ??

There is a bandwidth limiting module for apache, seems to cause some
people problems tho...

Won't do anything for email,ftp etc...

gsh