rwi@naucse.UUCP (Robert Wier) (12/20/88)
Hi. I have been asked to aid in the design of a faculty data net to replace
the ailing Appletalk net which is currently in use (I think the problem is a
combination of bad connectors, poor routing, and near-maximum capacity
utilization). Since direct ethernet connections to each machine have been
ruled out (due to cost), we are thinking of going to a Phonenet type
arrangement, probably with multiple branches in a backbone configuration.
Right now, we have about 17 Macs and 15 PCs which would go onto the net
(the Macs immediately, the Pcs within a few months when localtalk cards
are accumulated). Initial activity will mostly be to use file servers and
print on LaserWriters. However, we would also like to connect into our
(existing) Mac student lab network, and also include the 50 or so student
lab PCs eventually (as cards can be obtained).
The problem is that it has been quite difficult to get answers from the
vendors as to what will work with what. The following are questions
which are still unresolved, and I'd be most grateful for any comments from
you netters out there.
1) We would like to have students be able to "turn in" lab assignments
via the network. Ideally, there would be a drop-in folder arrangement
which the students could use to submit labs, and the appropriate
faculty member could retrieve these when ready (ie, a Rwrite onlyS
facility). I understand that TOPS and APPLESHARE have arrangements
along these lines. Is that true? Can anyone comment on the practicality
of this technique?
2) I am nervous about having only software isolation of the faculty
part of the net from the student lab net, so I've been looking into net
bridges. The Shiva NetBridge looks pretty good since it appears that
you can enable one-way accesses (ie FACULTY Net ->STUDENT Net; while
STUDENT Net != FACULTY Net). I realize that a number of controllers (such
as the Farallon Star Controller) allow the net manager to turn branches of
the net on and off, but this wouldn't really be practical on a day-to-day
basis. An alternative would be a bridge (or similar device) which would
allow access to the other branch via a user password, or something
similar. I have heard rumors that Farallon (or someone else) will be
coming out with this capability. Anyone know? How about other isolation
schemas which afford a reasonable measure of protection without being
excessively difficult to use? [ and I want 10 cent phone calls again, too! :-)
].
3. Our electronic tech only want to pull one cable (imagine that :-)). My
concern is that we not lock ourselves into (or outof) a system which will
limit future possibilities. We will shortly (I hope), for example, be
looking into connecting the net through a FASTPATH or GATORBOX to our
campus- wide ethernet to talk to some Microvaxes running Ultrix, a 8350
VAX running VMS, and so forth. At this point, no decision has been made
about running TCP/IP, whether via CAP, Aufs, NCSA Telnet, Alisa, Pacer,
Novell, TOPS, or whatever. Specifically we have been told by the Novell
rep that if we put our PCs onto local talk, that they can't guarantee that
NETWARE will be able to service the PCs on localtalk (although they are
relatively sure that the Macs will be able to communicate ok). Now it
seems to me that if the localtalk cards will let the PCs talk via the
phonenet, that the Novell software shouldn't make a distinction. However,
no one knows for sure :-( . Any comments that we *shouldn't* go ahead and
plan on using localtalk to connect the Macs and PCs into one net?
4. Network topology - One our our tentative designs basically has all 3
floors of the building connected into a passive backbone arrangement, with
the backbones having about 6 macs or pcs (each), meeting at one point
(probably in the middle floor phone closet), and interfacing into a bridge to
connect to the student net. We have looked at the Farallon Star Controller,
but don't have a good feel as to what the control facilities are. From
reading the literature, it appears that the net manager can turn branches
(up to 12) on or off, but does it do anything beyond that? Or is it
basically a repeater otherwise?
5. TOPS - we have looked at running TOPS (we are currently running
MacServe on our old net), but have grave reservations due to the necessity
of having a separate serial number on each TOPS node for each Mac. If a
student wipes out his system file on our student Mac net, then the lab
assistant would seem to have to have copies of 30 or so Macserve nodes
(ie, one for each machine) in order to get things going again, since its my
understanding that TOPS will not be happy with two or more identical
serial number nodes on the net. AND he has to get it onto the right
machine. AND there he has to be there at 3 AM when it gets to be down
toward finals. I'm not sure we can live with that. Has anyone been able to
get TOPS to site licence or something similar?
6. MAIL - What with the recent Internet problem, E- mail seems like a
weak point in system security. However, we still have not ruled it out. [ I
LIKE mailing programming assignments to my students at 2 AM :-} ] We'd
particularly like to be able to send mail to students on the student branch
of the net. Not being familiar with the mail systems out there, it is
possible to store mail on the disk server, and have a student notified when
he "signs on" to the Mac student net? As of now, we are not doing student
usage accounting or password systems on the student PC/Mac labs. Its not
clear to me how mail might function in this kind of environment.
Thanks in advance! ....
-Bob Wier at Flagstaff, Arizona Northern Arizona University
College of Engineering *usual disclaimers*
NAU Box 15600 ...arizona!naucse!rwi
Flagstaff, Az. BITNET: WIER@NAUVAX
86011 602-523-2052
(note: Bitnet node NAUVAX may not be
known yet to all stations)
College Motto: "The highest level of engineering in the Southwest
(7,000 feet)"