RELENG6/amd64: weird tcp window scaling behaviour

Hello,

maybe someone can tell if the following behavior is correct:

with: net.inet.tcp.recvspace=65536 as is default

fetch http://www.google.com/intl/en_ALL/images/logo.gif
generates 5 packets for the HTTP GET request
(window size = 65535, window scale = 1)

fetch http://www.freebsd.org/layout/images/logo-red.png
generates 1 packet for the HTTP GET request

The difference i see is the google server does not give a window scale
in the SYN-ACK, and the freebsd server does (scale = 0).


with: net.inet.tcp.recvspace=32768

both requests generate 1 packet for the HTTP GET (scale = 0)


If this behavior is by design my ASUS/P5B with Realtek 8168 doesn't like
it and gives a timeout for google.

Thanks
Jacco