my knowledge in Cisco devices also is very far from expert level I so
consulted with a colleague. His answer was the same - there is no Cisco
device to mess with your TCP stream. You can have a switch (at OSI layer
2) which deals with Ethernet frames, a router forwarding IP packets or L3
switch looking inside Ethernet frames and switching IP packets (at OSI
layer 3), some application (HTTP) load-balancers acting as application
proxies which multiplex requests to several hosts (at OSI layer 7).
You do not have a TSM connection from port 1500 or to port 1500 on Cisco
device. You can have a configuration:
HostA <--> (1 or more) Cisco <--> HostB
The traffic through these Cisco devices is either Ethernet frames or IP
packets. Only HostA and HostB assemble IP packets into TCP stream and only
their TCP-window sizes affect the connection. Cisco in the middle can drop
frames, drop or fragment IP packets and thus reduce throughput but cannot
interfere with TCP stream.
Zlatko Krastev
IT Consultant
Salak Juraj <[EMAIL PROTECTED]>
Sent by: "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]>
15.11.2002 13:38
Please respond to "ADSM: Dist Stor Manager"
To: [EMAIL PROTECTED]
cc:
Subject: Re: Poor Performance
Hello,
up to my (non-expert) knowledge
you can set tcp window size on various cisco devices.
The default seems to be 4128,
the command to change it is
ip tcp window-size <0-65535>
I never tried to change it ;)
regards
Juraj Salak
Es gibt tats�chlich auf den Cisco Ger�ten einen
> Befehl der die
> Windowsize betrifft (ip tcp window-size <0-65535>),
> standardm��ig steht
> dieser Wert auf 4128. Wenn ich das richtig interpretiere
> w�rde das bedeuten
> dass bis zu 4128
> -----Original Message-----
> From: Zlatko Krastev [mailto:[EMAIL PROTECTED]]
> Sent: Friday, November 15, 2002 1:14 AM
> To: [EMAIL PROTECTED]
> Subject: Re: Poor Performance
>
>
> What kind of Cisco is this?
> I am unaware of any Cisco non-networking device (if we assume iSCSI as
> half-networking) and networking ones should not mess with
> your TCP (OSI
> level 4; they ought to deal with IP - OSI level 3). Even if
> it really does
> look inside TCP stream it should not limit you to only 16kB!
> They ought to
> support RFC1323 and TCP window larger than 64 kB.
>
> Zlatko Krastev
> IT Consultant
>
>
>
>
>
>
> Lawrie Scott <[EMAIL PROTECTED]>
> Sent by: "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]>
> 12.11.2002 10:53
> Please respond to Lawrie Scott
>
>
> To: [EMAIL PROTECTED]
> cc:
> Subject: Re: Poor Performance
>
>
> Hi all
>
> Thanx for all the replies some of the tricks have helped a
> bit. However
> the TCPWindowsSize of 16 is set as CISCO has a limitation of
> TCPwindowsize of 16 and whenever we increase it to 63 the server then
> begins to timeout server requests and no backups happen.
>
>
> Lawrie Scott
> For: Persetel / Q Vector KZN
> Company Registration Number: 1993/003683/07
> Tel: +27 (0) 31 5609222
> Fax: +27 (0) 31 5609495
> Cell: +27 (0) 835568488
> E-mail: [EMAIL PROTECTED]
> <mailto:[EMAIL PROTECTED]>
>
