How to change TCP window size ?

How to change TCP window size ?

Post by Bernhard Ehle » Tue, 01 Aug 1995 04:00:00

I have a little problem with a PPP connection to my internet provider. He
installed a new set a modems and now a get a LOT of CRC errors (none before).
After some (well a lot of) testing i found that lowering the TCP window
size fixes my problem. That is consistent with the fact that he never has
poblems with DOS/Windows and MAC clients (They typically use small window

OK, I think that is HIS problem, but for the time I need to convice him, I
want to lower my window size. Currently I changed the following parameters
in /usr/src/linux/net/inet/tcp.h:
        #define MAX_WINDOW      3000
        #define MIN_WINDOW      1500
        #define MIN_WRITE_SPACE 1500
        #define TCP_WINDOW_DIFF 1500

It works, but I am unsure, if this has unwanted side effects. Is there
a better way to change the window size ? Btw. i use V1.2.12.

Best regards
Bernhard Ehlers

Kaltenkircher Platz 10                  simplicity only gets in the way.
D-22769 Hamburg, Germany                -- ACM SIGPLAN Sept. 1982