[NNTP] NNTP Compression

I mentioned this to Russ earlier today and was informed that there has 
been ietf-nntp list traffic on just such a topic.  I was unaware because 
I think I had somehow become unsubscribed to the list, or the messages 
sent to me were going into the bit-bucket.

I just read the list traffic, and IMHO doing this on a per-command basis 
is a non-starter.  I think doing this at the protocol level (or below) 
makes the most sense.  There are two ways to do this, either leverage 
the existing TLS compression, or add an NNTP command which enables its 
own compression.  I have been scolded in the past for suggesting that 
every site implement TLS because of the overhead, so an NNTP command 
seems to make the most sense here.

Below is the spec that the Lemonade WG did for IMAP and I think 
something similar would work for NNTP.  This could work for 
Client->Server traffic and/or Peer->Peer traffic.  I'd be willing to 
write up an I-D if folks think it would be useful.  Cyrus IMAP and 
Mozilla T-Bird v3 both support it and it works great.

http://tools.ietf.org/html/rfc4978

FYI, since all of our components in Cyrus use the same low-level 
protocol I/O layer (plaintext, TLS, SASL, COMPRESS=DEFLATE), I can have 
both a client and server NNTP implementation available in about 5min.

-- 
Kenneth Murchison
Systems Programmer
Project Cyrus Developer/Maintainer
Carnegie Mellon University