mmorse@NSF.GOV (02/09/90)
This subject comes up fairly frequently, so I'm risking violating
net etiquette by posting the answer to the net rather than just to the
asker (mikeb@ucs.adelaide.edu.au). This is the standard message I've
been sending out on this subject (it's written for people who know
PCs, not UNIX or TCP/IP):
(Updated March 28, 1989)
This message describes a mail gateway at NSF that transfers
mail between cc:Mail and the research and academic networks
(primarily the DARPA/NSF Internet and BITNET). I've also
enclosed limited information on similar gateways running at Proteon
and other sites.
The gateway used at NSF was adapted from the gateway
developed by Al Marshall at Proteon, Inc.
What is cc:Mail?
cc:Mail, a commercial product, is an electronic mail system that
runs on PC's connected to a LAN. All the executable code runs on
the PC's and mail is exchanged by accessing a database on a LAN file
server. cc:Mail runs on a variety of LAN hardware and software,
including any LAN system that provides DOS with virtual drives. It
is currently (March '89) limited to MS-DOS PC's; however, a
MacIntosh version has been announced. Compared to typical time-
sharing mail implementations it is inexpensive, fast, well-documented,
and user-friendly. It is easily installed and most users will not require
any training to use it.
cc:Mail uses a proprietary message format and transfer
protocol, but "import" and "export" utilities are provided to allow the
transfer of mail with other systems. More information about cc:Mail
can be obtained by contacting the vendor at 800-448-2500.
Hardware and Software Environment
At NSF the gateway is implemented on a PC running MS-DOS
and a VAX running UNIX. The PC does not talk directly to the
research and academic networks. It transfers mail through the UNIX
machine which has links to the Internet, BITNET, and UUCP. Any
host that can be accessed from the UNIX machine can be addressed
from cc:Mail. For this document, the PC will be referred to as the
"Gateway PC," and the UNIX machine as the "Internet Host."
The Internet Host is a VAX 785 running Ultrix. It runs
MMDF (Multi-Channel Memo Distribution Facility) for its MTA
(Mail Transport Agent). MMDF is supported by CSNET (Computer
Science Network). It performs essentially the same functions as
sendmail on many UNIX computers.
The Gateway PC is a PC AT clone. It communicates at 9600
baud with the Internet Host using an asynchronous protocol known as
Phonenet. The software to support Phonenet on the PC is PMDF
(MMDF in Pascal). PMDF is licensed software available to CSNET
members, or directly from the University of Pennsylvania. The
Gateway PC is also on the 3COM LAN that supports cc:Mail at NSF.
Software on the PC provides translation of the mail between
the Internet format (RFC 822) and the proprietary cc:Mail format.
Address resolution and final delivery is accomplished on the UNIX
machine.
Addressing
The cc:Mail system uses real names for addresses, and its
directories and documentation expect this. What RFC 822 users
would think of as a "host name" is called a "Post Office" in cc:Mail.
A typical address on cc:Mail looks something like this:
Michael Morse at NSF-DC
Internet addresses look something like this:
mmorse@note.nsf.gov
The approach taken at NSF was to ignore the real-name bias
of cc:Mail and refer to users in cc:Mail by their UNIX usernames.
The reasons for this are mostly historical: All NSF employees already
had usernames that they used on the UNIX mail system and were
known by on the Internet. Also, at the time the gateway was
developed cc:Mail had no aliasing capability. In addition, NSF's
connection to the BITNET limits usernames to eight characters.
Addressing cc:Mail Users from the Internet
The cc:Mail users are addressed exactly as if they were using
the Internet host for mail, so mail to me, for example, is addressed as
follows:
mmorse@note.nsf.gov
Mail is transparenetly directed to the Gateway PC using the
aliasing feature of MMDF.
Addressing Internet Users from cc:Mail
A special cc:Mail Post Office called "INTERNET" (at Proteon
it's called "ARPA") is set up. To send mail to the Internet, cc:Mail
users select that Post Office. The cc:Mail system then prompts them
for the Internet address. The address is combined to look something
like this:
lforest@terp.umd.edu at INTERNET
Return Addresses
The gateway ensures that mail in both directions is "replyable."
Mail coming into cc:Mail has "at INTERNET" appended to the return
addresses. Mail going out from cc:Mail carries the return address of
the Internet Host (note.nsf.gov).
Binary File Transfer
The cc:Mail system allows users to easily attach PC files (text
or binary) to messages. The gateway encodes attached files into 7-bit
ASCII using the uuencode scheme originally developed in the UNIX
environment. Incoming uuencoded files are similarly decoded into
cc:Mail file attachments.
Implementation Details
The Gateway PC runs 3COM 3+ drivers to access the file
server for cc:Mail, and uses its serial port to communicate with the
Internet Host using the Phonenet protocol. The PC runs a batch file
that repeatedly runs the following steps:
1) It runs the cc:Mail EXPORT utility to collect (onto its local
disk) the mail for the Internet Host.
2) It translates the mail to Phonenet format and builds a file for
each message in the Phonenet queue directory.
3) It runs the Phonenet MASTER program that logs onto the
UNIX machine and delivers and receives mail.
4) It looks for incoming mail in the Phonenet queue directory.
For any mail found it translates it and appends it to a file for
the cc:Mail import utility.
5) It runs the cc:Mail IMPORT utility to deliver the mail to
cc:Mail.
6) It checks for any housekeeping it needs to do, such as running
its own backup. After housekeeping is complete it returns to
step 1.
The gateway has been running at NSF since July 1988. It has
proved to be very reliable and requires virtually no human attention.
It currently handles about 1000 messages a week for about 225 cc:Mail
users at NSF. The main constraint on the gateway is the 9600 baud
line between it and the Internet host. This limits the transfer to about
1 megabyte per hour.
Other Gateways
The other gateways that I know of use the same basic
architecture: A PC on the LAN uses cc:Mail's IMPORT and
EXPORT programs to transfer mail with the LAN. The PC translates
the mail to Internet format and transfers it to an Internet Host for
delivery. The primary difference between the gateways is the protocol
used to exchange mail with the Internet Host.
We use Phonenet at NSF because it was readily available, we
were familiar with it, and it was specifically designed to allow easy
access to Internet mail over serial lines. However, the Phonenet
protocols are not widely available.
There are two other protocols that have been used successfully:
UUCP and SMTP.
UUCP
The UUCP model is almost identical to the gateway used at
NSF. The only difference is that UUCP has a different mail format
and queueing structure. UUCP is widely available for PC's, in both
supported (commercial) versions and public domain varieties. A
gateway using UUCP has been running successfully at Oregon State
University at least as long as NSF's. A limitation of some of the
UUCP implementations is that usernames can only be 8 characters.
SMTP
The SMTP model is used at Proteon Inc. It uses TCP/IP
protocols to transfer mail to the Internet Gateway. It has an ad-
vantage that it operates at LAN speeds. The gateway requires that a
single PC be configured to communicate with both TCP/IP and
whatever LAN protocols are being used. Co-existance between LAN
software and TCP/IP is possible with many systems. Since DOS is not
a good operating system for multi-tasking, the Proteon implementation
uses two Gateway PC's, one for receiving mail and one for sending.
Another possibility for an SMTP gateway is to use an 80386-
based UNIX machine (such as the SUN 386i) that can run both DOS
and SMTP in a multi-tasking environment. As far as I know nobody
has implemented a gateway for cc:Mail on this architecture, but it has
been done for other LAN mail systems.
Availability of the Software
If you are a CSNET member (or have a PMDF license), are
running MMDF, and would like to implement the PhoneNet gateway,
please contact me:
Mike Morse -- mmorse@note.nsf.gov
I will send you the complete package. If you have experience
with PC's and Internet mail systems you should be able to get it
running in a day or so. If you want to modify the gateway to run with
UUCP, let me know and I will send you the non-PMDF portion.
Al Marshall of Proteon has made his gateway available to
anyone via anonymous ftp. Contact:
Al Marshall -- acm@proteon.com
You can purchase a UUCP gateway from Oregon State. Write to:
Richard Kinoshita -- kinoshir@ccmail.orst.edu (Internet)
kinoshir@ORSTVM (BITNET)
[Since I wrote this, cc:Mail has hired Richard to develop and support
gateways. --MHM]
If you have any questions, please feel free to write to me, or if
that fails, give me a call:
Mike Morse -- (202) 357-7659
Disclaimer
Neither Al Marshall nor I have any connection with cc:Mail
other than as customers. This message is in no way an endorsement of
cc:Mail by the National Science Foundation.tkevans@fallst.UUCP (Tim Evans) (02/11/90)
In article <9002081357.aa23656@Note.NSF.GOV>, mmorse@NSF.GOV writes: > > I've also > enclosed limited information on similar gateways running at Proteon > and other sites. > > There are two other protocols that have been used successfully: > UUCP and SMTP. > > You can purchase a UUCP gateway from Oregon State. Write to: > > Richard Kinoshita -- kinoshir@ccmail.orst.edu (Internet) > kinoshir@ORSTVM (BITNET) > > [Since I wrote this, cc:Mail has hired Richard to develop and support > gateways. --MHM] > We run Richard's package (called "OutMail") at the Social Security Admini- stration in Baltimore, where we have a potential universe of 5,000+ E-Mail users--1,200 UNIX and 4,000 DOS users. As Mike notes, Richard is now employed by cc:Mail, Inc., where, as I understand it, he's primarily working on a SMTP package that cc:Mail will sell and support. He's been fairly responsive to my requests for bug fixes in OutMail. Since SSA has a major contract with cc:Mail, we were able to get OutMail; you may not because the copyright is held by Oregon State. (BTW, Richard's OSU mail address still works, even though he's working in Palo Alto.) With respect to the overall package, as Mike points out, cc:Mail works well in the DOS environment. Because most of our users, both DOS and UNIX, are relatively unsophisticated, though, they've been having trouble understanding and using the gateway to get E-Mail to each other. Of particular note is the uuencode/uudecode feature noted above. This is most a user problem, not a problem with cc:Mail or OutMail--obviously. The one comment that should be made, though, is that cc:Mail is an expen$ive package and that, in order to run any sort of gateway, including the public domain ones Mike describes in this posting, you have to buy expen$ive add-ons from cc:Mail. cc:Mail's message format is some sort of encrypted, compressed one that is a proprietary secret, so you have to buy the Import/Export utilities from them. Presumably, the SMTP gateway Richard is working on will also be expen$ive. DISCLAIMER: I'm not speaking for SSA; I just administer the gateway. -- UUCP: {rutgers|ames|uunet}!mimsy!woodb!fallst!tkevans INTERNET: tkevans@wb3ffv.ampr.org Tim Evans 2201 Brookhaven Ct, Fallston, MD 21047 (301) 965-3286