Bandwidth question

I'm sending multiple files through my ds3 connection from one unix
machine to another via ftp.

It seems that when looking at the router interfaces, that the bandwidth
is only utilizing 65% of the total pipeline.

Is there any way to make this figure higher so that way my ftp
connection goes faster? Or are there too many other factors that play
into tcp/ip and ftp and bandwidth?

I'm kind of a newb and would appreciate detailed and thorough analysis
answers.

thanks!

"dawaves" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com

> It seems that when looking at the router interfaces, that the
> bandwidth is only utilizing 65% of the total pipeline.
....
> I'm kind of a newb and would appreciate detailed and thorough analysis
> answers.

For starters, it would be helpful if you gave a "detailed and thorough
analysis" of how you arrived at the 65% bandwidth-utilization figure.

ynotssor wrote:
> "dawaves" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed) oups.com
>
>> It seems that when looking at the router interfaces, that the
>> bandwidth is only utilizing 65% of the total pipeline.
> ...
>> I'm kind of a newb and would appreciate detailed and thorough analysis
>> answers.
>
> For starters, it would be helpful if you gave a "detailed and thorough
> analysis" of how you arrived at the 65% bandwidth-utilization figure.
>

It would also be helpful if you looked at the replies to the poster who
was trying to figure out why his 1Gb link was underutilized. Most of
what was said there should be applicable.

dawaves <(E-Mail Removed)> wrote:
> I'm sending multiple files through my ds3 connection from one unix
> machine to another via ftp.

Are you sending those files one at a time, or are you opening multiple
FTP sessions?

What size files are you sending?

How many are "multiple?"

> It seems that when looking at the router interfaces, that the
> bandwidth is only utilizing 65% of the total pipeline.

> Is there any way to make this figure higher so that way my ftp
> connection goes faster? Or are there too many other factors that
> play into tcp/ip and ftp and bandwidth?

There are many factors. First, is there any packet loss for the FTP
data connection? Statistics from netstat from before and after a
transfer, or over an interval during a transfer would be good. Run
the before and after snapshots through "beforeafter" to take the
deltas. ftp://ftp.cup.hp.com/dist/networking/tools/

One fundamental limit to the bandwidth of a TCP connection is the
window size divided by the round-trip-time - W/RTT. The longer the
RTT the larger the window you need to achieve a given throughput.
Sooo...

What is the RTT between the two systems? Ping times would be a decent
first approximation.

What window size is being used for the FTP data connection? A tcpdump
trace that included the _start_ of the FTP session would be good - one
needs to see the start to see if window scaling is being used.

rick jones
--
oxymoron n, commuter in a gas-guzzling luxury SUV with an American flag
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

"Allen McIntosh" <(E-Mail Removed)> wrote in message
news:7atxg.908$(E-Mail Removed)

>>> I'm kind of a newb and would appreciate detailed and thorough
>>> analysis answers.
>>
>> For starters, it would be helpful if you gave a "detailed and
>> thorough analysis" of how you arrived at the 65%
>> bandwidth-utilization figure.
>
> It would also be helpful if you looked at the replies to the poster
> who was trying to figure out why his 1Gb link was underutilized.
> Most of what was said there should be applicable.

If you want to direct the OP's attention to another thread, please provide
the OP a definitive means of identifying it, rather than directing your
comment at me.

ynotssor wrote:
> "Allen McIntosh" <(E-Mail Removed)> wrote in message
> news:7atxg.908$(E-Mail Removed)
>
>>>> I'm kind of a newb and would appreciate detailed and thorough
>>>> analysis answers.
>>> For starters, it would be helpful if you gave a "detailed and
>>> thorough analysis" of how you arrived at the 65%
>>> bandwidth-utilization figure.
>> It would also be helpful if you looked at the replies to the poster
>> who was trying to figure out why his 1Gb link was underutilized.
>> Most of what was said there should be applicable.
>
> If you want to direct the OP's attention to another thread, please provide
> the OP a definitive means of identifying it, rather than directing your
> comment at me.
>
Sorry - replied in a hurry and got the wrong article. The comment was
directed at the OP, not you.

The thread was "pushing beyond 400mbit?"