Newsgroups: bit.listserv.nodmgt-l
Date:         Wed, 23 Dec 1992 11:29:09 EST
From:         Jim Conklin <CONKLIN@BITNIC.BITNET>
Subject:      New CREN Guidelines for Maximum File Size and File Handling
Comments: To: bitnews@BITNIC.BITNET
Comments: cc: technews@BITNIC.BITNET, crenbdst@BITNIC.BITNET

    An increase in the BITNET maximum file size for CREN is necessitated
by increased expectations and the need for moving large files (including
mail files) across the network.  Such an increase is facilitated by the
increased speed of the links to the BITNET "Core" and to many branch
nodes, and the increased capabilities of most BITNET nodes.

    The CREN Board has therefore approved the following two-stage
proposal as a compromise to address (1) the opinion of the CREN
Technical Advisory Committee and others that the maximum file size
should be at least 3 MB, and (2) the concerns expressed by three of the
fourteen US Core nodes about the unknown impact of an increased BITNET
maximum file size on their operations, and their resulting unwillingness
to support an increase to more than 1 MB at the present time.

    This action does not affect the maximum file-size restrictions of
other Cooperating Networks which currently have a maximum file size
defined, but they, of course, may choose to increase theirs also, and to
revise their Acceptable Use Policies accordingly.  Where such Acceptable
Use Policies have been provided to BITNIC, they are available from
LISTSERV@BITNIC as the files
        net-name NET_USE
(For example, CREN NET_USE is CREN's Acceptable Use Policy.)  New and
revised Acceptable Use Policies sent to DOCUMENT@BITNIC will be
similarly posted on LISTSERV@BITNIC.
    The CREN Acceptable Use Policy has been updated to reflect the new
policy.  A new file, BITNET FILESIZE, is also available on
LISTSERV@BITNIC with the new guidelines as shown below; it will be
updated to reflect changes in these guidelines as they occur.


The New Guidelines:
-------------------

    Effective January 1, 1993, the BITNET maximum file size for CREN is
eliminated and replaced by the following new guidelines for the handling
of BITNET files by CREN members.  The guidelines apply to both mail and
non-mail BITNET files.

    It is expected that all nodes will make a best-effort commitment to
accept and forward (if appropriate) files of up to 1 MB in size.  It is
*not* required or expected that nodes refuse larger files.   It is
further expected that all Core nodes, and branch nodes to the extent
possible, will accept and forward files required for BITNET operation
(e.g., BITEARN NODES, LISTSERV updates), up to at least a 3 MB limit.

    Information about the impact of this change will be sought in May or
early June from the operators of the US Core nodes.  If, at that time,
all US Core nodes are agreeable to handling files up to 3 MB in size,
the 1 MB BITNET "file expectation size" defined in the previous
paragraph for CREN will automatically increase (without further Board
action) to 3 MB effective July 1, 1993.  If any of the US Core nodes
cannot handle files up to 3 MB in size and cannot be replaced with new
Core node(s) which can handle 3 MB files, the CREN Technical Advisory
Committee and Board will again review the situation, and the CREN Board
will decide upon appropriate action.  In either case, the automatic
second increase or need for further review will be broadly announced in
late June.

    If the node's storage or transmission capability, or the line speed
between it and the next node to which the file is to be forwarded, prove
inadequate, in the judgment of the forwarding node, for storage or
transmission of the file, the node may either delay delivery or refuse
to accept or deliver the file, as described below.

    Notification must be sent to the sender of a file whenever it is
impossible to complete delivery of that file.  If the size of the file
not being delivered is greater than the BITNET "file expectation size",
it is desirable that the error message specify that this is the reason
the file was not forwarded.  Only enough of the file to facilitate its
identification should be included in the non-delivery notice; the whole
file should not be returned if the file is large.  NOTE: In practice,
the inclusion of "file expectation size exceeded" messages in this
notification may have to wait until software has been modified and is
therefore suggested rather than required.

    Nodes may delay the transmission of large files as necessary for
effective queue management, except that every effort should be made to
deliver all files within two working days.  (If that is repeatedly not
possible for some node, software and/or network reconfiguration should
be done if possible, to relieve the situation.)  In extreme situations,
delivery of especially large files may be delayed until the weekend.
Delays longer than a week should generally be treated as non-delivery,
with the delayed files being purged and non-delivery messages sent to
their senders.

    Network users should minimize the transmission of very large files
by not transferring them frivolously, by compressing large files when
feasible, and by ftp'ing large files directly over the Internet when
that is a feasible option.  Note, in this regard, that the current
BITEARN NODES file, and other files, are available via ftp from
bitnic.educom.edu, vm.utdallas.edu, and file.nic.surfnet.nl (cd
/netman/mgmt-earn).