Doug Bostrom ([EMAIL PROTECTED]) wrote:

> As I understand it, some requests arriving at my node are forwarded to other nodes, 
>with the results 
> being passed back through my node. If my inbound connecton is 2X, and my outbound 
>connection is 1X, 
> this means that data going _across_ my node can arrive at my node at twice the rate 
>it can leave my 
> node.

It's even more lopsided than that.  You could get a request for a
key that you've already cached.  In that case, your outgoing bandwidth
usage will be *more* than your incoming bandwidth usage.  On the other
hand, if you're a large consumer of Freenet data, then you might be
downloading a lot of keys that don't immediately get sent back out.
But I tend to be one of the types of people who shares a lot more than
he consumes.

Oh, and ADSL is half duplex.  You must take that into account also.
If your outgoing bandwidth is saturated (the normal state for me),
then your incoming stuff will have massive delays.

And then there's the small but non-negligible overhead involved in
establishing TCP connections and doing the occasional DNS lookup
for nodes that are using hostnames.  The TCP handshaking should be
fairly symmetric; DNS lookups tend to be larger in the incoming
direction (since the DNS server can send additional information
such as SOA and NS records), but they add latency if either direction
is congested.

What it comes down to is this: you cannot control the packets you
receive from the Internet; people could flood you at will and there's
nothing you could do about it except asking your ISP to block them.
So any attempt to control incoming packets is not only futile, but
silly.  But you have full control over what you *send*, and you
want to make sure that high-priority packets (such as DNS lookups)
make it out in a reasonable amount of time.  There are several
strategies for achieving this, depending on the nature of your
traffic and what operating system you're running on the gateway.
If we assume Linux 2.4, then you'll be looking at the QoS (quality
of service) stuff in netfilter/iptables.  In *BSD, you'll probably
be using ALTQ.

-- 
Greg Wooledge                  |   "Truth belongs to everybody."
[EMAIL PROTECTED]              |    - The Red Hot Chili Peppers
http://wooledge.org/~greg/     |

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