waters@viking.DEC (Lester Waters) (05/30/85)
I've been recently installing an ethernet with many machines. Ive been reading ver. 2.0 of the DIX Ethernet specification, and found the various cable length/repeater restrictions placed on an ethernet. My question is: how does a DELNI impact this specification? We have one main 'hose' with H4000s along it. Each H4000 is connected to a DELNI. One second DELNI is cascaded with the first. DELNI's really can't be considered repeaters, can they (excuse my ignorance please)? The ethernet spec states that a maximum of two repeaters my appear in the path between two nodes. Hmmm. I also seem to remember that as well as restrictions on cable lengths, etc., there is a maximum sum of cable that can be in one ethernet (that is, the sum of all the lengths of all the cables). Any ethernet experts out there? Thanx, Lester Waters ...!decvax!decwrl!dec-rhea!dec-viking!waters Waters%Viking.DEC@DECWRL (Arpa)
mfe@leadsv.UUCP (Mark Ellson) (06/03/85)
In article <2371@decwrl.UUCP>, waters@viking.DEC (Lester Waters) writes: > > I've been recently installing an ethernet with many machines. > Ive been reading ver. 2.0 of the DIX Ethernet specification, and found > the various cable length/repeater restrictions placed on an ethernet. > My question is: how does a DELNI impact this specification? Referring to the DELNI Owner's Manual, you will find a table on page 35 which describes the impact that the DELNI has on cable lengths in various configurations. Basically, when using a DELNI to provide multiple connections from a single tranceiver, the DELNI represents 15 meters of tranceiver cable. Thus the maximum distance from tranceiver to device is reduced from 50 meters to 35 meters. Similar boxes provided by other manufacturers have the same type of restriction on the length of the tranceiver cable. It is critical that you find this specification for any unit you plan to use, and keep it in mind while designing your network. Mark Ellson Lockheed Missiles & Space Co. ihnp4!amd!cae780 \ > !leadsv!mfe ucbvax!sun!sunncal/