Compiling on Windows, and a question of policy

Vernon Schryver
Sun Dec 1 04:16:06 UTC 2002

> From: Paul Wright <>

>                                       ...  I'd most likely do this by
> compiling dccproc under Cygwin and then piping stuff to it.

Beware of the difficulties presented by the use of UNIX mapped files
and sockets in the DCC client code.  These problems can be overcome,
but would be unwise to ignore them or to take shortcuts such as
discarding the relevant DCC client code.

> Spampal runs under Windows. It is a POP3 proxy intended for personal
> use ...

> ...
> - Increases the number of people who are reporting to the DCC, so adds
>   to load on public servers. Probably only matters if the plugin is wildly
>   successful.

That covers the big problem.  It is not technical but financial and
administrative.  Who pays for and would be responsible the computers,
bandwidth, electrical power, and people required for servers giving
DCC service to the masses?  If such a product were used by only a few
10,000 end users, it could be accommodated.  However, 10,000 end users
are only 0.002% of an Internet of 500,000,000 and growing. says there are currently fewer than 20,000
SpamPal users.  They would not bog down the public DCC servers, but 1%
of the Internet certainly would.  Even 0.1% would force the resignation
of several of the dozen machines currently offering public DCC services.
You can't process 1M DCC transactions/day on a 128 MByte PC and have it
do anything else.

Anyone distributing a serious end-user DCC product must make provisions
for DCC servers for that product or be seen as doing the same sort of
thing that spammers do.  The difficulties of providing DCC servers for a
few million end users is a major reason why I've not started what I've
long talked about, something like a POP3/IMAP proxy version of dccproc.

I've thought of suggesting to James Farmer that he consider porting
dccproc into his product, but this problem of servers has stopped me.

> ...
> - The user's ISP should really be the one doing this. (But most of them
>   aren't).

The majority of the DCC checksums handled by the network of ~100 DCC
servers now in the network are accumulated and compressed by servers
run by ISPs for their customers.  (Note that I am not saying that most
of those 100 servers are run by ISPs.)

Vernon Schryver

More information about the DCC mailing list

Contact by mail or use the form.