http bytes -> network ratio ?

[Rob Hartill <ro...@imdb.com>]

Anyone know (rough figures will do) by how much on average each
byte sent via HTTP expands to when sent packaged up over the net ?

I'm trying to find an answer to a question such as 'how much bandwidth
do I use sending 1k of HTTP data in 1s.'

cheers
rob

Re: http bytes -> network ratio ?

[Rob Hartill <ro...@imdb.com>]

On Thu, 5 Feb 1998, Ben Laurie wrote:

> Rob Hartill wrote:
> > 
> > Anyone know (rough figures will do) by how much on average each
> > byte sent via HTTP expands to when sent packaged up over the net ?
> > 
> > I'm trying to find an answer to a question such as 'how much bandwidth
> > do I use sending 1k of HTTP data in 1s.'
> 
> If rough answers will do, then I'd say add 10-20% overhead. I have no
> doubt that people can cook up splendid counterexamples, but that's a
> realistic figure given no information whatsoever :-)

thanks for the info Ben, Marc and Dean.

ballpark figures were fine.

Re: http bytes -> network ratio ?

[Ben Laurie <be...@algroup.co.uk>]

Rob Hartill wrote:
> 
> Anyone know (rough figures will do) by how much on average each
> byte sent via HTTP expands to when sent packaged up over the net ?
> 
> I'm trying to find an answer to a question such as 'how much bandwidth
> do I use sending 1k of HTTP data in 1s.'

If rough answers will do, then I'd say add 10-20% overhead. I have no
doubt that people can cook up splendid counterexamples, but that's a
realistic figure given no information whatsoever :-)

Cheers,

Ben.

-- 
Ben Laurie            |Phone: +44 (181) 735 0686|Apache Group member
Freelance Consultant  |Fax:   +44 (181) 735 0689|http://www.apache.org
and Technical Director|Email: ben@algroup.co.uk |Apache-SSL author
A.L. Digital Ltd,     |http://www.algroup.co.uk/Apache-SSL
London, England.      |"Apache: TDG" http://www.ora.com/catalog/apache

Re: http bytes -> network ratio ?

[Dean Gaudet <dg...@arctic.org>]

It's way to hard to figure out this way.  It's way easier to just log the
total filesize of every object sent, and ask either your tcp/ip stack
(i.e. accounting rules if you have them) or your nearest router for how
much the machine really sent. 

Otherwise you have to consider stuff like the initial and final handshakes
of every connection... various MTU sizes... retransmissions... yadda
yadda.

Dean

On Wed, 4 Feb 1998, Marc Slemko wrote:

> On Wed, 4 Feb 1998, Rob Hartill wrote:
> 
> > 
> > Anyone know (rough figures will do) by how much on average each
> > byte sent via HTTP expands to when sent packaged up over the net ?
> > 
> > I'm trying to find an answer to a question such as 'how much bandwidth
> > do I use sending 1k of HTTP data in 1s.'
> 
> Figure out the MTU, add your 40 bytes of overhead and you have the answer
> for large data transfers.
> 
> For small data transfers, you have to add the header which biases things a
> lot.  
> 
> It can vary widely from site to site what the average mix of these two
> is...
> 
> 

Re: http bytes -> network ratio ?

[Marc Slemko <ma...@worldgate.com>]

On Wed, 4 Feb 1998, Rob Hartill wrote:

> 
> Anyone know (rough figures will do) by how much on average each
> byte sent via HTTP expands to when sent packaged up over the net ?
> 
> I'm trying to find an answer to a question such as 'how much bandwidth
> do I use sending 1k of HTTP data in 1s.'

Figure out the MTU, add your 40 bytes of overhead and you have the answer
for large data transfers.

For small data transfers, you have to add the header which biases things a
lot.  

It can vary widely from site to site what the average mix of these two
is...