hostname: naic.nasa.gov
directory path: files/general_info/
filename: using-east-gateway.txt
updated:  April 14, 1993 (AM)

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                NASA Science Internet Interoperability Gateway 
	       ------------------------------------------------
	
The NASA Science Internet Project Office (NSIPO) has funded an Interoperability
Gateway to facilitate the exchange of e-mail, file transfer and remote logon
capability between NSI-DECNET and NSI-TCP/IP, as well as between TCP/IP-based
networks such as the NSFnet, NSFnet regionals, MILNET, et al. and DECNET 
networks (DDCMP protocol) such as the High Energy Physics Network (HEPnet) and
ESnet/DECNET. 
 
The Interoperability Gateway at Goddard Space Flight Center (GSFC) is based on
a Digital Equipment Corporation (DEC) microVAX 3300 currently running Ultrix
3.1.  This system runs a DEC layered product, DECNET-Ultrix Gateway, that
provides for native mode DECNET and TCP/IP protocol interpertation. This system
is attached to both the TCP/IP and DECNET portions of the NSI.

This article will detail how to make use of this gateway. No account or special
access is needed on the gateway machine to make use of these capabilities. 
Interoperability functions, e-mail and file transfer, are translated from one
protocol to the other in a one step operation and are not "staged"
onto the Gateway, translated, and then sent off to their end destination. 

The Interoperability Gateway at GSFC is known as: 

	NSI-DECNET name/address:   EAST  6.769
	NSI-TCP/IP name/address:   east.gsfc.nasa.gov  128.183.104.4


1.  SENDING ELECTRONIC MAIL BETWEEN TCP/IP AND DECNET HOSTS


    a.  From TCP/IP to DECNET

From an Internet machine mail can be sent to a user on a VMS/DECNET machine by
mailing to: 
                          user@host.dnet.nasa.gov

NOTE: If the TCP/IP mail software does not use a nameserver to get information
about hosts, you may have to use the following syntax (most implementations
support MX records in their mail software so this is unnecessary):

                      user%host.dnet@east.gsfc.nasa.gov 

...where "host" is the name of the VMS/SPAN host you wish to send mail to, and
"user" is the login name of the person you wish to send to there. 


    b.  From DECNET to TCP/IP

To send mail to an Internet site from a VMS/DECNET host, mail to the address: 

                           EAST::"user@host.domain"   

...where "host.domain" is the full name of the Internet host you wish to send
mail to, and "user" is the login name of the person you wish to send to there
(you must also type the quotes as shown). NOTE: If node EAST is not defined on
your system, see your local system manager or substitute "6913" for "EAST".


2.  FILE TRANSFERS
 
    a. File transfers invoked from a VMS/DECNET machine.

       To copy a file from an Internet machine with FTP capability to your
       local VMS/DECNET machine, you type the command:

	$ COPY EAST"host.domain!user password"::"remote-file" VMS-file

Where "host.domain" is the full name of the Internet host you want to get the
file from, "user" is the login name on the Internet machine, "password" is the
login password for the designated user account on the Internet machine, and
"remote-file" is the name of the file to fetch from the Internet machine (the
syntax of remote-file is dependent on the operating system on the remote
Internet machine).  "VMS-file" is the name of the local file to create on your
VMS/SPAN machine (and is in normal VMS syntax).  Again, if node EAST is not
defined on your system, see your local system manager or substitute "6913" for
"EAST".  In the above COPY command, you must type the quotes exactly as shown. 

       To transfer a file from your VMS/DECNET machine to an Internet machine,
       simply reverse the order of the arguments to the VMS COPY command,
       i.e. put the local VMS-file name first and then EAST and following
       parts of the remote file specification last, so that you get:

	$ COPY VMS-file EAST"host.domain!user password"::"remote-file"

If the Internet machine happens to be set up for anonymous FTP and the file you
want has been placed in the anonymous FTP directories there, you can use a user
name of anonymous and put anything in as the password (although a password must
still be present; by convention the last name of the invoking user is often
used as the password). 

    b. File transfers invoked from an internet machine

       To transfer a file from an FTP-capable Internet machine to a remote
       DECNET machine, type the command:

	ftp east.gsfc.nasa.gov 

NOTE: If you get an "unknown host" error, you can use the IP address
      128.183.104.4 to make the FTP connection.

Once you have connected and received the login prompt, respond with:  

                                host::user 

Where "host" is the name of the VMS/DECNET host you wish to send a
file to, and "user" is the login account you wish to place the file
in.  When prompted for the password, give the password for this
account.  You may then use normal FTP commands such as "get" and "put"
to transfer files.  It is not possible to invoke a gatewayed transfer
from the Internet side without a password for a VMS/DECNET account
because VMS/DECNET networking does not provide any kind of
passwordless access like anonymous FTP.

    c.  BINARY FILE TRANSFER

A word of warning:  UNIX systems do not have a record structure format like VMS
files do.  Therefore, if a binary file is sent from a VMS/DECNET node through
the gateway to an Internet machine using the techniques described above, the
record structure information is necessarily lost, even if the destination
Internet machine is also running VMS.  Files sent through the gateway from the
Internet side to a VMS/DECNET machine in binary mode will create files on the
destination VMS machine that have fixed length 512-byte records.  It is also
likely that if the Internet machine is not a DEC machine or other machine that
uses DEC byte ordering, you may run into byte ordering problems when the data
in the destination file is interpreted. 

East WILL however support the transfer of nonstandard files given certain
constraints.  This includes non-ASCII files such as backup savesets, 
executable images, ASCII files in nonstandard record format etc.  The 
procedure is somewhat different.  You will need to use the VMS EXCHANGE 
utility on BOTH sides. Thus it is assumed that you will be copying from one
VMS machine to another.  Alternatively, you may copy from a VMS machine to
a UNIX or ULTRIX machine which is FTP-accessible to a (local) VMS machine.
In this case, you will need to transfer the two files mentioned below from
the UNIX or ULTRIX machine to the local VMS machine, process the files, then
transfer the final file back to the UNIX/ULTRIX box.

EXCHANGE is a VMS utility originally intended for handling the 
non-VMS/RMS structure of console media.  As such, it is ideally suited 
for handling almost any unusual record structure.  When transfering data
between different operating systems (in this case VMS and the Ultrix
operating system on East) different file structures are maintained.  
To insure the integrity of your data, you will have to create and copy 
across a File Definition Language (FDL) file describing the original 
structure of your data.

To transfer a nonstandard file through east, use the following steps:

1/ Create an FDL of the file and ship that across in the normal fashion.

  $ANALYZE/RMS/FDL filename
  $COPY filename EAST"host.domain!user password"::"remote-filename"

2/ Ship across the file using a similar format in the EXCHANGE utility.

  $EXCHANGE/NETWORK/TRANSFER=BLOCK -
   filename EAST"host.domain!user password"::"remote-filename"

3/ On the remote end, restore the original file characteristics using
   the FDL within the EXCHANGE utility.

  $EXCHANGE/NETWORK/TRANSFER=BLOCK/FDL=filename.FDL filename filename


In the following example, a user wishes to send a backup saveset named
TEST.BCK to an Internet site named hotel.mars.gov.  At the remote site,
he has an account with a username of ROBERTS and a password of ABDFG$35

1/ He creates the FDL and sends it across.

  $ANALYZE/RMS/FDL TEST.BCK
  $COPY TEST.FDL EAST"HOTEL.MARS.GOV!ROBERTS ABDFG$35"::"TEST.FDL"

2/ He then sends across the file using EXCHANGE.

  $EXCHANGE/NETWORK/TRANSFER=BLOCK -
   TEST.BCK EAST"HOTEL.MARS.GOV!ROBERTS ABDFG$35"::"TEST.BCK"

3/ He restores the saveset to its original format and removes the intermediate
   files.

  $EXCHANGE/NETWORK/TRANSFER=BLOCK/FDL=TEST.FDL TEST.BCK TEST.BCK
  $PURGE TEST.BCK
  $DELETE TEST.FDL;



SHORTCUT

In some cases, it may be possible to send nonstandard files using mail
and without going through East at all.  However, you must meet the 
following criteria.  

1/ Both machines must be VAXes running VMS version 5.0 or higher and
2/ You have DECNET connectivity to the NSI and 
3/ The remote end has IP connectivity to NSI.

In such a case, the easiest way to transfer the file is using the VMSMAIL 
utility with the /FOREIGN qualifier.  To send, use the following syntax:

  $MAIL/FOR filename NSINIC::SMTP%"user@host.domain"

You may optionally add a subject line explaining the contents of the message
to the remote user.  As an example, to send an executable named PROCESS.EXE
to user smith on machine grumpy.gov you would enter

   $MAIL/FOR PROCESS.EXE/SUBJECT="PROCESS.EXE, EXTRACT TO UNLOAD" -
     NSINIC::SMTP%"SMITH@GRUMPY.GOV"

At the remote end (Internet node grumpy.gov) user Smith need only enter 
the MAIL command EXTRACT/NOHEADER PROCESS.EXE to unload the file. 


3.  REMOTE LOGINS

    a.  Logging into Internet hosts from VMS/DECNET hosts

    To log onto an Internet host with telnet capability from a VMS/DECNET
    host, execute the command:

                            $SET HOST EAST 

Again, if node EAST is not defined on your system, see your local system
manager or substitute "6913" for "EAST".  When you receive the Ultrix login
prompt as shown, give the response as shown below: 

	Ultrix-32 V3.1 (Rev. 9) (east.gsfc.nasa.gov) 

	login: host.domain!
              |--your response--|

where host.domain is the full name of the Internet host you wish to connect to.
You should receive a login prompt from the designated Internet machine. 

    b.  Logging into VMS/DECNET hosts from Internet hosts

To log onto a VMS/DECNET host from an Internet host, issue the command:

                          telnet east.gsfc.nasa.gov

As with FTP above, if the gateway machine is not known to your local machine,
you may telnet to the IP address 128.183.104.4.  When you receive the login
prompt from the gateway machine as shown, respond as shown. 

          east.gsfc.nasa.gov login:  host::
                                    |--your response--|

where "host" is the name of the VMS/DECNET host you wish to log on to (followed
by the double colon as shown).  If the VMS/DECNET host is not known to the
Gateway, you may use its DECNET node number if you happen to know it (followed
by the double colon) and the Gateway will connect you.  Afer entering this
line, you should see the usual "Username:" prompt from the VMS/DECNET machine. 

If you experience any problems, please contact:

                Jeffrey Burgan
                NASA Ames Research Center
                Moffett Field, CA  94035
                415-604-5705  FTS 464-5705
                TCP/IP:  jeff@nsipo.arc.nasa.gov
                DECNET:  EAST::"jeff@nsipo.nasa.gov"

