[OT] Little TCP/IP question

[OT] Little TCP/IP question

[Marcin Sura]

Hi

  I know, that I'm asking in wrong place, but I think that here I can
  find answer for my question ;)

  Ok. The scenario:

  I have 512/128 adsl. I have access to 2 ftp servers. To both
  (separately) of them I can upload files with full speed (128
  kbit/s).

  And now, when I start upload files at the same time (one session per
  server) to those servers, my upload speed splits. But it splits irregular.
  To first  server I have for example 80 kbits, to another the rest. And this
  cane change in time, but always one have more than another.

  And here are my questions.

  On what rules this is based?

  What is the TCP/IP algorithm that control usage of bandwidth by sessions
  (flows?)?

   I think, that isn't (bandwith / number_of_session). Is that true?

   

  

-- 
Pozdrawiam
 Marcin                         mailto:slacklist@op.pl

Re: [OT] Little TCP/IP question

[Chris Brenton]

On Sun, 2004-08-22 at 18:44, Marcin Sura wrote:
>
>   What is the TCP/IP algorithm that control usage of bandwidth by sessions
>   (flows?)?

This is going to vary based on the window size. Its not surprising that
the first session is getting more bandwidth as its had more time to
negotiate a larger window size and a smaller inter-packet gap. Its also
not surprising that this changes over time due to the latency caused by
the line being saturated.

If you want to even this out, your best bet would be to implement some
QoS. Not sure its so far off that its really worth it though.

HTH,
Chris