Both client and server are configured to operate with window scaling...Tcp1323opts = 1, tcpwindowsize = 524 k, etc. During some SYN, ACK/SYN handshaking sequences, the scaling option is on and at the correct scale factor. Other times it is not...especially when I need it, such as file transfer. Any other thoughts...
thanks
Jim
-----Original Message-----
From: gabriel olariu <[email protected]>
To: JTEOIETF <[email protected]>; [email protected] <[email protected]>
Date: Wednesday, January 17, 2001 2:40 PM
Subject: Re: RFC1323 Window scale behavior
You need to verify that both server and client have the stack configured with Tcp1323Opts=1.
Also, the window sizes need to exceed 64K for large windows to kick in.
Look at the TCP options exchanged in the SYN sequence and you'll see who's doing
large windows and who's not.
For the registry parameters that need to be set, consult "Microsoft Windows 2000 Server" white paper.
Only Win98/98SE/ME/2000 support large windows. Win98 has a documented bug.
gabriel
----- Original Message -----
From: JTEOIETF
To: [email protected]
Sent: Wednesday, January 17, 2001 1:46 PM
Subject: RFC1323 Window scale behavior
Hello,
I have been performing simulations in preparation of an upcoming on-orbit test of TCP applications over satellite. The problem is the RFC 1323 window scaling option does not always operate as expected. For example, capturing the packets for an FTP session reveals the scaling option is on during the initial session setup (I.e. login, cd-ing, etc) but when a file transfer is requested and another session opens, the window scale options are not present, therefore limiting to a 64k window. I have a roundtrip delay upwards of 2500 ms and bandwidth of 1.544 Mbps. Any input to this behavior is appreciated.
Equipment:
-IBM ThinkPad 600 w/ Windows 2000 sp1
-Cisco 2611 routers, using high speed serial ports on WAN side
-KIV-19 crypto (capable of 13 Mbps)
-Adtech SX12 link simulator
Thank you,
Jim
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