[list.ietf-nntp] compression methods

lear@turbo.bio.net (Eliot) (06/25/91)

With regard to the COMPRESSION option, I'd rather that the compression
method be negotiated such that prearrangement need not be necessary in
all cases.  Unfortunately, yes, this would also require a name
registry.  If a compression is used that is not in the registry, then
it must be prearranged.

Comments?

Eliot Lear
[lear@turbo.bio.net]

sob@tmc.edu (Stan Barber) (06/25/91)

Why build compression in? Why not just use the same mechanism uucp/batching
uses now? Adding compression adds ALOT of overhead. Using image/binary and
the existing news batching adds very little.

If the goal it to make low speed lines usable (say over a NetBlazer)
with NNTP for TRANSMISSION (not READING), compression in nntp is not necessary.


-- 
Stan           internet: sob@bcm.tmc.edu         Director, Networking 
Olan           uucp: rutgers!bcm!sob             and Systems Support
Barber         Opinions expressed are only mine. Baylor College of Medicine

lear@turbo.bio.net (Eliot) (06/25/91)

Let me take up both sides of this issue.

For Compression:

It saves money if you're unfortunate enough to have to pay usage
sensitive rates.  My understanding is that this is the case for certain
transatlantic rates, and it places like Korea.

Compression might be only a variant of IMAGE for some implementations if
they store articles in compressed form (TMNN comes to mind; does CNEWS
allow articles to live on the disk in compressed form?).

Against compression:

It adds overhead and it requires a name registry, and it adds a little
bit of hair into the implementations.

Comments?
Eliot Lear
[lear@turbo.bio.net]

Harri.Salminen@funet.fi (Harri K Salminen) (06/25/91)

Your message dated: Mon, 24 Jun 91 21:25:57 PDT

> It saves money if you're unfortunate enough to have to pay usage
> sensitive rates.  My understanding is that this is the case for certain
> transatlantic rates, and it places like Korea.

Compression is also much desired for slow speed lines be they volume
charged or not. Many Central European (former European except USSR)
countries for example have 9.6 lines that they intend to multiplex with
other traffic to get even a very slow IP connection. Also many IP links
that go over 64K or lower speed X.25 networks could benefit from
compression. Currently those places prefer batched uucp or NJE transfers
because of scarce bandwidth. Enough for European problems, I think
this should convince you that we need OPTIONS for several compression
schemes that could be used link by link basis.

> Against compression:

> It adds overhead and it requires a name registry, and it adds a little
> bit of hair into the implementations.

If it's an option it could even be agreed bilaterally although names for
few popular compression schemes could be defined in the RFC. Anyway it
should be optional so that if you don't like you don't support it.

> Comments?
> Eliot Lear
> [lear@turbo.bio.net]

Harri

mcb@presto.ig.com (Michael C. Berch) (06/25/91)

[Eliot writes:]
> With regard to the COMPRESSION option, I'd rather that the compression
> method be negotiated such that prearrangement need not be necessary in
> all cases.  Unfortunately, yes, this would also require a name
> registry.  If a compression is used that is not in the registry, then
> it must be prearranged.
> 
> Comments?

Ideally, I think it would be best if we could eliminate all
requirements for name registration.  This question has come up with
respect to authentication and/or encryption scheme names, as well.
Since it seems to be accepted that in the present model NNTP
connections exist only by prearrangment, then I do not think it is too
much to ask that "nonstandard"[1] feed parameters be prearranged also.
Presumably NNTP implementations will make reference to certain
well-known compression or authentication schemes, and these names will
form the basis for mutual pre-arrangement.  To try to do more commits
the community to yet another cumbersome name registration scheme.

--
Michael C. Berch  
mcb@presto.ig.com

[1] A "standard" feed would be the present common modality, i.e., a
feed of by an active transmission client without compression, batching,
authentication, encryption, or state information other than IHAVE.