On Mon, Sep 27, 2004 at 09:06:49AM +0400, Vlad Doubrov wrote: > > BTW, does anybody know if such a proxy is available in open-source? > I've been searching google for a while, nothing found, that seems quite > unreal. If you tuned your Linux stack well enough then you won't need the proxy :) > OpenVPN transfer: http://www.vtx.ru/tunnel.txt It went into congestion control early. That means you've got a cached congestion window setting. Please clear it by doing ip ro flush cache before you start the download. You should also verify using ip ro ls cache that there is no cwnd setting for that destination address. However, even with that reduced congestion window setting, you still experienced packet loss as well as packet reordering. So non-congestive packet loss is indeed the likely cause of your performance problems. There are two approaches that you can take. You could identify the source of the packet loss and attempt to eliminate it. Or you could try to tune the Linux TCP stack to react better. Since you're running 2.4.27, you should be able to try the various congestion control algorithms (BIC/Vegas/Westwood) by enabling them through /proc/sys/net/ipv4/tcp_*. One clue is that during your clear-text transfer, there were no packet losses at all even though the transfer rate is higher. So if the packet loss is on the server-side of the satellite, then you can start by checking if your tunnel packets are being discriminated against by one of the routers. Of course if the loss is on the other side of the satellite then your only choice is to tune the sender stack. Good luck, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
