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13 Dec 73
NIC 20854, RFC 599: Update on NETRJS
Network Working Group Robert T. Braden
NIC #20854 UCLA/CCN
RFC #599 December 13, 1973
UPDATE ON NETRJS
A. INTRODUCTION
In July 1971, CCN published RFC #189 defining NETRJS, a private
protocol for remote job entry. NETRJS provides a Network interface
to CCN's rje program called RJS (Remote Job Service).(3) As noted in
an earlier RFC,(6) "RJS" is the proper name of a software package
existing ony at CCN, not a generic term for rje.
For over two years now, CCN has provided rje service to the Network
using NETRJS. We know of the following distinct implementations of
NETRJS user porgrams:
RAND OS/MVT on 370/158 (originally on 360/65)
UCLA-NMC SEX on Sigma 7
Illinois ANTS on PDP-11
Utah Tenex on PDP-10
MIT-DMCG ITS on PDP-10
Harvard DEC system on PDP-10
UCSB OS/MVT on 360/75
ISI,BBN,NIC,I4 Tenex on PDP-10
We apologize to anyone slighted by omission from this list. Writing
a new user process for NETRJS has proved to be a modest and
straightforward task.
During the month of October, 1973, CCN processed 1373 batch jobs via
NETRJS. The complete statistics are:
1,373 Jobs submitted
1,105 Jobs "printed"
0 Jobs "punched"
Braden [page 1]
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NIC 20854, RFC 599: Update on NETRJS
49,400 Cards "read"
822,900 Lines "printed"
18,907 Pages "printed"
393.6 Connect hours
The average job submitted was 360 lines ("cards"), and returned 745
lines on 17.1 pages. These figures are fairly typical.
B. NEW ICP SOCKETS
At the request of the Socket Czar, Jon Postel, (see RFC #433) we
intend to move the NETRJS ICP sockets from 11, 13, and 15 to 71, 73,
and 75, respectively. At present, NETRJS is available from either
socket subspace, so system programmers responsible for maintaining
NETRJS user processes can switch over at their leisure. We plan to
"decommit" sockets 11, 13, and 15 on July 1, 1974.
Those hosts which access NETRJS via socket 1 are unaffected.
C. NEW NETRJS
Last Fall, CCN installed a new implementation of its NETRJS server.
An internal NETRJS rewrite was necessitated by other system changes
and was timed to coincide with installation on September 5 of the
"last release" of OS/360, Release 21.7. The new version of NETRJS
contains a number of internal improvements over the original version
written two years ago. There are also a few external differences, as
follows:
1. No More Squish
The long-standing "squish" problem in NETRJS has been fixed.
This problem arose because of the "squishiness" of Network data
transfer, i.e. the variable delay between originator and
receiver processes due to NCP buffering. The result was that a
short print output file could be "transmitted" by RJS,
dequeued, and discarded at CCN before the first message had
actually reached the remote host. If the remote host crashed
or the user tried to cancel (and save) the output stream, it
was too late; the output was lost in the "squish". We were
careless about this in the first version. Now NETRJS awaits
the RFNM from the end-of-data mark before telling RJS to
discard the job output.
Braden [page 2]
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NIC 20854, RFC 599: Update on NETRJS
2. Timeouts
The new verson is a little tougher on timeouts, to free CCN
resources when users are slow.
a. Signon Timeout
If the user, after connecting to NETRJS and receiving the
READY message, fails to send a valid SIGNON command
within 3 minutes, CCN will close the Telnet connections.
b. Data Transfer Timeout
(1) CCN will abort the READER data transfer connection
if the user site leaves the connection open without
sending any bits for 5 minutes.
(2) CCN will abort the PRINTER or PUNCH data transfer
connection if the user site stops accepting bits for 5
minutes.
3. New Messages
The NETRJS messages to the remote terminal have been revised to
better distinguish problems at CCN, at the user site, or in the
Network. See Reference 8 for a complete list.
4. Subsystem Interrupt
The user can send a Control-C to terminate his NETRJS session
either before or after signon. Continuation is not possible
after the Control-C.
This provides an escape for a user who for some reason can't
signon or signoff or close his Telnet connection. If the user
entered via the RJS command in Socket 1, Control C will return
him to the Server Telnet command level.
One other improvement will reduce user frustration: NETRJS now
returns an INVALID SIGNON message if the user enters anything but a
valid SIGNON command after initially connecting to the NETRJS server.
Braden [page 3]
13 Dec 73
NIC 20854, RFC 599: Update on NETRJS
D. CLARIFICATIONS AND AMENDMENTS TO NETRJS PROTOCOL
Over the past two years, system programmers writing NETRJS user
processes have pointed out areas of the protocol which were poorly
defined in RFC #189. In addition a few minor changes have been made,
largely as the result of implementation accidents.
1. The jobname header of a print file does not have an ASA
carriage control byte. However, it will be encoded in the
format (compressed or truncated) selected by a particular
VRBT.
2. The punch connection sends 81 byte records, the first byte
being a blank carriage control character. This is contrary to
RFC #189 and is illogical; it was an implementation bug which
we kept for compatibility.
3. Page 3 of RFC #189 defined fixed values for the user's data
transfer sockets relative to his Telnet sockets. In fact,
NETRJS does not enforce these user data transfer sockets but
will accept RFC's for any user sockets.
4. RFC #189 specified a choice of two character mappings for the
virtual remote batch terminal: EBCDIC and ASCII (-68). An
ASCII-63 mapping was later added for the convenience of users
with Model 33-like keyboards (RAND, actually). The ASCII-63
mapping is selected by doing an ICP to socket 75 or by
entering "TTYRJS" in CN's Telnet Server. figure 1 shows the
actual ASCII-63 mapping in use today. This supercedes the
earlier version of the mapping, shown in RFC 338.
5. The ASCII-68 mapping specified in RFC 189 was also changed to
provide unique mappings for all ASCII characters. The present
ASCII-68 mapping used by both NETRJS and TSO at CCN is shown
in Figure 1.
E. RJS TERMINAL OPTIONS
When a new NETRJS virtual terminal is defined, certain options are
available; these options are listed below. If the user does not
specify otherwise, CCN will use truncated data format and turn all
other options on.
1. Truncated/Compressed Data Format
As explained in RFC 189, a virtual remote batch terminal under
RJS may use either the turncated data format (default) or the
Braden [page 4]
13 Dec 73
NIC 20854, RFC 599: Update on NETRJS
compressed format for printer and punch output. With the
truncated format, CCN merely removes trailing blanks from each
output line; if compressed format is specified, CCN will also
encode strings of inbedded blanks or other repeated characters.
CCN will accept either format in the card reader stream,
regardless of the terminal option. See Reference 9 for
discussion of the virtues of compression.
2. Automatic Coldstart Job Resubmission
If "R" (Restart) is specified in the accounting field on the
JOB card and if this option is chosen, RJS will automatically
resubmit the job from the beginning if the CCN operating system
should be "coldstarted" before all output from the job is
returned. Otherwise, the job will be lost and must be
resubmitted from the remote terminal in case of a coldstart.
3. Automatic Output RESTART
With this option, transmission of printer output which is
interrupted by a broken connection always starts over at the
beginning. Without this option, the output is backspaced
approximately one page when restarted, unless the user forces
the output to start over from the beginning with a RESTART
command when the printer connection is re-opened and before
printing begins.
4. Password Protection
This option allows a password to be supplied when a terminal is
signed on, preventing unauthorized use of the terminal ID.
5. Suppression of Punch Separator and Large Letters.
This option suppresses both separator cards which RJS normally
puts in front of each punched output deck, and separator pages
on printed output containing the job name in large block
letters. These separators are an operational aid when the
ouptut is directed to a real printer or punch, but generally
undesirable for an ARPA user who is saving the output in a file
for on-line examination.
Braden [page 5]
13 Dec 73
NIC 20854, RFC 599: Update on NETRJS
F. WARNING ON TENEX NETRJS USER PROCESS (6)
The Tenex implementation of NETRJS user program is a command normally
called "RJS". This program has some pitfalls of which users should
be aware.
1. For strictly historical reasons, the commonly-available
version of the Tenex RJS command uses Socket 15, and
therefore, the ASCII-63 translation. We hope to propagate
soon a version which uses the ASCII-68 mapping via Socket 73,
and stamp out the earlier version.
2. The Tenex RJS command fails to recognize the US character
sometimes used instead of CR LF as end-of-line. As noted in
RFC 571, the Tenex user FTP program has the same problem.
3. The Tenex RJS command truncates without warning card images
exceeding 80 characters in length.
G. REFERENCES ON NETRJS
1. "Interim NETRJS Specifications", R. T. Braden. RFC #189: NIC
#7133, July 15, 1971.
This is the basic system programmer's definition document, and is
really the final specification. The proposed changes mentioned on
the first page of RFC #189 were never implemented, since the DTP
then in vogue became obsolete.
2. "NETRJS Remote Operator Commands", R. T. Braden. NIC #7182,
August 9, 1971
This document together with References 3 and 8 define the remote
operator (i.e. user) command language for NETRJS, and form the
basic user documentation for NETRJS at CCN.
3. "Implementation of a Remote Job Service", V. Martin and T. W.
Springer. NIC #7183, July, 1971.
4. "Remote Job Entry to CCN via UCLA Sigma 7; A scenario", UCLA/CCN.
NIC #7748, November 15, 1971.
This document described the first NETRJS user implementation
available on a server host. This program is no longer of general
interest.
Braden [page 6]
13 Dec 73
NIC 20854, RFC 599: Update on NETRJS
5. "Using Network Remote Job Entry", E. F. Harslem. RFC #307: NIC
#9258, February 24, 1972.
This document is out of date, but describes generally the Tenex
NETRJS user process "RJS".
6. "EBCDIC/ASCII Mapping for Network RJS", R. T. Braden. RFC #338:
NIC #9931, May 17, 1972.
The ASCII-63 mapping described here is no longer correct, but
CCN's standard ASCII-68/EBCDIC mapping is described correctly.
7. "NETRJT--Remote Job Service Protocol for TIP's", R. T. Braden.
RFC #283: NIC 38165, December 20, 1971.
This was an attempt to define an rje protocol to handle TIPs.
Although NETRJT was never implemented, many of its features are
incorporated in the current Network standard RJE protocol.
8. "CCN NETRJS Server Messages to Remote User", R. T. Braden. NIC
#20268, November 26, 1973.
9. "FTP Data Compression", R. T. Braden. RFC #468: NIC #14742,
March 8, 1973.
Braden [page 7]
13 Dec 73
NIC 20854, RFC 599: Update on NETRJS
FIGURE 1. NETRJS CHARACTER MAPPINGS AT UCLA-CCN
The character set of the VRBT (VIRTUAL Remote Batch Terminal) is
determined by the initial connection to RJS, as follows:
VRBT Character Set | ICP Socket OR Server Telnet Command
----------------------------------------------------------------
EBCDIC | 71 | RJS
ASCII-68 | 73 | ARJS
ASCII-63(tty) | 75 | TTYRJS
These mappings are as follows:
ASCII-68 Mapping:
Corresponding graphics are mapped one-to-one.
Unmatched graphics are mapped as in the table below.
ASCII-68 controls are mapped one-to-one onto the matching
EBCDIC controls, with DC4(ASCII) mapped onto TM(EBCDIC).
ASCII-63 Mapping:
Corresponding graphics are mapped one-to-one.
ASCII codes X'61' - X'7A' (the ASCII-68 lower case letters are
mapped onto EBCDIC lower case.
Unmatched graphics are mapped as shown in the table below.
ASCII-63 controls X'00' - X'1F' are mapped as for ASCII-68.
ASCII codes X'60' and X'7B' - X'7E' are mapped as shown in the
following table.
Braden [page 8]
13 Dec 73
NIC 20854, RFC 599: Update on NETRJS
EBCDIC | ASCII-68 VRBT | ASCII-63 VRBT
---------------------------------------------------------------
vertical bar X'4F' | vertical bar X'7C' | open bracket X'5B'
not sign X'5F' | tilde X'7E' | close bracket X'5D'
cent sign X'4A' | back slash X'5C' | back slash X'5C'
underscore X'6D' | underscore X'5F' | left arrow X'5F'
. X'71' | up arrow X'5E' | up arrow X'5E'
open bracket X'AD' | open bracket X'5B' | . X'7C'
close bracket X'BD' | close bracket X'5D' | . X'7E'
. X'8B' | open brace X'7B' | . X'7B'
. X'9B' | close brace X'7D' | . X'7D'
. X'79' | accent X'60' | . X'60'
Note : this page is available on-line as HELP RJSCHARS in CCN's
Telnet Server (Socket 1). The on-line version is set up to be
typed out on an ASCII-68 terminal.
Braden [page 9]