roy@phri.UUCP (Roy Smith) (02/05/86)
In an effort to save cabling costs for our planned workstation
network, we are considering alternatives to the standard big yellow cable
with a transceiver for each node. We have not yet settled on Sun as the
vendor, but if we do we'll probably want to do something like this:
<==//===========X=========================X=================X=====//==>
# # #
# ------- -------
# | /50 | . . . | /50 |
---------- # ---------- ------- -------
| Vax- | --------- | Sun- |
| 11/750 |####| DELNI |####| 3/160C |
---------- --------- ---------- ------- -------
# # | /50 | . . . | /50 |
# # ------- -------
---------- # # ---------- | |
| Sun- |####### #######| Sun- |-------x-----------------x-----//-->
| 3/180S | | 3/180S |
---------- ----------
Key: === Fat Ethernet cable --- Thin Ethernet cable
X Ethernet transceiver x Thin coax "tee" fitting
### Ethernet drop cable | Thin drop cable
One 3/180 will be file-serving for the diskless nodes directly
connected to it via the thin cable. Those nodes, both 3/180's, the 3/160,
and the 11/750 will all be physically near each other. The other 3/180
will be serving the 3/160 and the other diskless nodes. Naturally, we'll
want to do rlogin's and ftp between everything. In addition, we'll
probably have other stuff on the cable (and the DELNI) eventually.
Does anybody have any experience with mixing these various types of
cabling? Are there any problems I should be aware of? Is the DELNI really
transparent; does it act just like a passive device? Any problems running
NFS and ND through it?
We're a suspicious of the thin cable altogether. Besides the
length limitations, what are the differences between it and regular
Ethernet? How does the software treat the thin segment? Do I end up with
two logically distinct networks which need some sort of software gateway
between them? If this is the case, does the standard IPC software handle
this or will I need some other package to implement the gateway?
--
Roy Smith, {allegra,philabs}!phri!roy
System Administrator, Public Health Research Institute
455 First Avenue, New York, NY 10016