Hi, I'm hoping someone can help me with an apparent 'per-connection' cap on
by home network.
I have hit a snag in my quest to set up a home network and am hoping someone
may be able to help or at least point me in the right direction.
What I have:
1. A PII 300 running NT4.0 sp6, 128M RAM with a 10/100 Mbps Ether card (PCI)
hard set to operate at 100 Mbps half duplex; and
2. A P120, RH7.0 with all current patches, 48M RAM, 2 10/100 Mbps Ether
cards, one on Cable modem, one on home network. Running IPChains with Masq
for firewall and modem sharing.
There seems to be an artificial cap on the realizable bandwith on any
one connection. I think this because of two things:
1. When FTPing between NT box and internet I get a throughput avg of
8.5Kbps with a maximum just over 9.0Kbps. If I use a program such as
GetSmart (which breaks the file up into chunks and then downloads the chucks
separately) and use 6 connections, each connection has the same bandwith
cap. Downloading from the same site to the RH box gives throughput (at the
time I did it) of 85+Kbps.
2. I installed Samba for file sharing and, as a test, tried to transfer
files from the RH box to the NT machine (initiated from NT box). The
throughput (as determined by performance monitor) showed the same cap of
about 8.5 to 9.0 Kbps.
The total available bandwith between the machines is not the issue as, with
multiple connections, I get a high transfer rate. I have seen some
references to adjusting the MTU in the NT registry and I tried that. It had
no affect of course as the NT machine is receiving packets, not generating
them. Other references talk about packet window size etc but I don't think
that is the problem as again, the total transfer rate with multiple
connections is high. An ifconfig in RH reveals that the MTUs for both cards
are set at 1500, that the collisions are near zero and that there are no
other obvious problems.
A pre-response to questions:
Yes, the RH box is performing as a firewall for the home network.
Yes, when plugged into the cable modem directly, the NT machine gets the
As far as user limits on bandwith etc, I too have seen references to that.
It seems to me though that, at lest from what I have seen, it has to be
explicitly set up and is not part of a standard install. Nothing in the
firewall script imposes such a limit. The NT machine does log into an
account for Samba purposes but that does not apply to FTP transfers where
the RH box is simply establishing the masquaraded connection to the Internet
and has no knowledge of a 'user'.
I'm stumped and would appreciate any help or suggestions.