martin@tibbs.UUCP (Martin Walker) (09/07/90)
I have various questions concerning a LAN design I am doing at the moment,
and I'd appreciate any help I can get with the following questions. You can
either post or e-mail any comments you have to make, and I'll summarise the
responses. Thanks in advance people :
(1) I know that Banyan Vines servers can communicate with each other over
a TCP/IP bcakbone to form a larger virtual network. Does this mean, though,
that the PC's attached to the Vines Network can use the server as a
transparent TCP/IP gateway, ie. can the PC's use NFS, FTP, Telnet, etc. to
communicate with other TCP/IP hosts on the ethernet backbone?
If yes, I assume some sort of TCP/IP software for the PC's (such as PC-NFS,
Locus's TCP/IP for DOS, ISOLINK PC/TCP, etc.) will be required. What would be
suitable, and roughly how much would this software cost (in $)?
(2) In a LAN using an ISOLAN fibre optic hub to connect remote copper segments
together, is there any real reason why the fibre segments always seem to be
terminated with fibre optic repeaters (ie. one duplex fibre port and one AUI
port)? Wouldn't a fibre optic transceiver (also one duplex fibre and one AUI
port) work just as well? All the sample configurations given on the back of
brochures show the fibre-to-copper transition being made by a fibre optic
repeater connected (via the AUI port) to a transceiver on the (thick or thin)
ethernet co-axial cable. Direct fibre-to-DTE connections on the other hand are
made via the fibre optic transceiver. The length of the fibre link doesn't
really seem to be a factor in this question. The maximum hub-to-repeater or
hub-to-transceiver fibre link distance in both cases appears to be the same :
2 km. What is wrong with making the fibre-to-copper transition by attaching
the fibre optic cable to a fibre optic tranceiver and then connecting the
fibre optic transceiver to a standard ethernet transceiver via AUI cable?
(3) The restrictions on the number of repeaters in the path between DTEs
in a fibre network are not clear. IEEE 802.3 specifies that the path between
any 2 DTEs may cross 2 local or 1 local and 2 remote repeaters and 3 copper
segments (of maximum length 500m). Surely there should be much more relaxed
restrictions on fibre networks. Timing budgets shouldn't be much of a problem
in fibre networks because propogation is so fast. Signal deterioration in fibre
is clearly also much less of a factor. Does anyone have a reasonably
comprehensive set of rules governing the configuration of mixed fibre and
copper LANs? Failing that could someone give me an answer as to whether a
path between two DTEs consisting of the following is acceptable :
copper segment - repeater - copper segment - fibre optice repeater - fibre
optic cable - fibre optic multiport repeater - fibre optic cable - fibre
optic repeater - copper segment - repeater - copper segment ?
(4) Apparently a MicroVAX II running VMS can be put on a TCP/IP network
using a DELUA ethernet adapter and FUSION TCP/IP software for VMS. Does
anyone have a current price on this (my most recent prices are $4756 for
the ether adapter and $8033 for FUSION TCP/IP s/w) or alternative suggestions
(along with their prices)?
(5) Is SNA software a *requirement* to be able to run TCP/IP software on an
IBM 9370 with VM/CMS or do I just not understand *anything* about IBM
comms :-) ?
(6) Given an IBM 9370 and an IBM 4381, both running VM/CMS, and an IBM 6150
running AIX, the three being connected to each other already with BISYNC
channels (providing facilities for file transfer and terminal sessions) and
with none of them having SNA software, is it a reasonable proposition to
connect them to a TCP/IP backbone by putting an ethernet card and TCP/IP
software on the 6150 and using it as a gateway to the other two m/f's?
Up to 128 simultaneous sessions spread between the three IBM's could be
required. In other words, workstations on the LAN will log in to the 6150
and then start up a terminal session on, say, the 9370. Only terminal sessions
and limited file transfers are required. Would this arrangement bring the 6150
to a grinding halt :-( ? I would be inclined to think not since terminal
sessions don't really result in all that much traffic...
Anyway, thanks to all of you for your remarkable forbearance .... :-)
--
Martin Walker | ..!ddsw1!olsa99!tabbs!tibbs!martin
@ | "The more people I meet, the more
The Ideal | I like my dog..."
BBS | (:-D D-:) bruce@ccavax.camb.com (09/10/90)
In article <729@tibbs.UUCP>, martin@tibbs.UUCP (Martin Walker) writes: > > (4) Apparently a MicroVAX II running VMS can be put on a TCP/IP network > using a DELUA ethernet adapter and FUSION TCP/IP software for VMS. Does The Q bus MV2 won't take the Unibus DELUA. The old DEQNAs still work, but DEC has promised they won't in the next major VMS release, and so after much pressure from ANGRY users now has a trade-in program where you get the NEW DELQA for $600. The new card comes first, and you must return the old or be billed for the full $3k-$4k or whatever the DELQA normally costs. This program ends soon... So obviously you need a DELQA, or the DESQA version which has the MV3 type metal faceplate and a built in BNC'd tranceiver as well as the AUI port. As for S/W, we are VERY happy with TGV's MultiNet. I don't have their phone # handy, but you can send mail to: vance@tgv.com
martin@hq.af.mil (Gregory.J.Martin) (09/10/90)
I can only answer you question regarding Banyan VINES and TCP/IP (BTW, I'm reading this news over Banyan's TCP/IP option). If all the servers are loaded with TCP/IP routing Option, they can speak over a TCP/IP backbone, however, they'll probably use VINES IP unless you filter it somewhere. The servers can act as a TCP/IP gateway if you buy the proper option also. We're using FTP's PC/TCP to link our PC's to the Internet. To have the servers do the routing, you'll need the "IBanyan" driver and you'll have to set the server up to do "Proxy" ARP for the PCs using the PC's IP address and the servers Ethernet (or LAN) address. Make sure you get VINES 4.0, we've experienced a lot of problems which I suspect will be fixed under 4.0. If you have any questions respond to Martin@hq.af.mil