From: Chris Home (clarson52@comcast.net)
Date: Fri Jan 17 2003 - 00:22:09 GMT-3
You also have to take TCP window sizing, acknowledgements and other such TCP
stack info into account when doing tests using file transfer.
There are many factors that could be a contributor to this issue.
On high speed low latency links like an OC-3 or better it is recommended
that you change the TCP send and recieve window size to it's max. I had a
customer that was not getting near the throughput they should be over an
OC-3 doing data replication. We changed the tcp send and recieve window size
and wa-la. Fixed.
I know tcp uses a sliding window, but it is based on the bounds placed on
it by windows if your using windows. A lot of those programs claiming they
can give you better performance on your Internet connection (you know those
damn pop-up/pop-under ads) are based on adjusting parameters in the TCP
stack.
----- Original Message -----
From: "Pc9101" <kieu@hn.vnn.vn>
To: "Ccielab@Groupstudy.Com" <ccielab@groupstudy.com>
Sent: Thursday, January 16, 2003 8:56 PM
Subject: Re: How fast can Ftp speed reach?
> Hi Fan !
>
> FTP may useful to test a low-speed wan interface, but high speed Campus
...
> In the latter case, your PC not strong enough to receive 12,5Kbytes/sec
> (100/8) The main reason is Harddisk writting speed.
>
> In the first case, the result may lower a bit in compare to Bandwidth/8,
> because of some kinds of header. FTP only count speed base on (amount of
> data)/sec
>
> There are some software that use to calculate the utilization of bandwidth
> like MTRG, or solarwind ...
>
> Cheers
> PC9101
>
>
> ----- Original Message -----
> From: "Fan Shan" <fansh@publicf.bta.net.cn>
> To: "Ccielab@Groupstudy.Com" <ccielab@groupstudy.com>
> Sent: Friday, January 17, 2003 7:33 AM
> Subject: How fast can Ftp speed reach?
>
>
> > May I ask a question not very relational to CCIE.
> > I am working for a IDC, one our customer complained their application is
> slow. They ask to test the ftp speed between our two switch port.
> > BTW, our structure is connecting customers to 6509 FE port,and 100M
> bandwidth supplied.We put 2 PC to 2 port, assign different vlan for these
2
> port,
> > one to be ftp client,another to be ftp server, the test result is
> 300-400Kbytes/s. We can see the mls entry established by the two ip
> address.The customer
> > says the speed is too slow comparing to the port speed(100M).But we
> think this may be resulted in the tesing PCs or some features of FTP
> protocol.
> > But I cannot explain why the speed maybe slow between two switch
ports,but
> very fast to other sites on the internet. Can someone help me to explain
> that?
> > We are using 6509 MSFC feature,different vlans are assigned to
different
> physical ports,and the routing protocol is OSPF.
> > .
> .
.
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