lmc@denelcor.UUCP (Lyle McElhaney) (01/21/84)
We (Denelcor, Inc) have installed an internal terminal switching system based on the Interlan NTS-10 terminal servers. Each NTS-10 box feeds eight ports/terminals. We have (right now) 12 boxes, which are all fully loaded with either users or machine ports (1 VAX and 4 PDP11/44s). This is in the nature of a review of this equipment. We have been told by Interlan that we have the most active system of this kind now in use. First our problems: Interlan sent no specs for the laying of the main coax cable and attachment of transcievers. Since we have a truely *strange* fire code in this district that requires *all* wiring to be in conduit, the coax was layed in conduit, and the transcievers attached at the points where the cable entered the boxes for that purpose. Fortunately, no tap was more than ~18 inches from the optimal attachment point, but physical squeezing of the cable in the boxes exceeded ethernet specs for bending radius. Moral: make sure the installation people know all about the Ethernet spec (apparantly still available from Xerox and/or Intel, possible DEC also, but not Interlan (!!)). Secondly, in order to install the transciever cables, the connector and ~4 inches of cable were cut, the cable installed, and the wire spliced. At transciever frequencies, the splices are an echo causing no-no. The spliced ends have been cut off and the connectors reinstalled to fix this. We also had a normal bunch of installation problems in a crowded lab environment - pinched power and transciever cables, jury rigged RS232 cable shorts, and so on. From Interlan's side, a new software release (NTS V1.02) has fixed a lot of problems, but there still seems to be some related to flow control (sometimes a control-s will loose you control of your terminal) and not all modem controls are handled correctly. Hardware problems in the boxes themselves include a suspected heating problem (Interlan is looking into incorporating a low power fan), quality control problems (under control now, we are told) and flakey transciever cable sockets on the box. We had to send a good many of our original boxes back for eco's and repair (but a bunch of those problems may well have been software). We are just now settling down from all this, and a follow-up article will describe how everything has turned out. Functionally, the system is a honey. You can be simultaneously logged onto up to four systems and switch to any of them at will. The command language interface is powerful, but awful to use (remind you of anything?). All in all, Interlan has been very cooperative in helping us find our and their own errors. We think it is a very good system, with only a few faults. -- Lyle McElhaney (hao,brl-bmd,nbires,csu-cs,scgvaxd)!denelcor!lmc