| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1558.1 | | NETCAD::STEFANI | Welcome to the Revolution! | Tue Jan 24 1995 15:49 | 13 |
| >>What's the max length UTP cable a DECconcentrator 900MX TP-PMD
>>can drive?
Uh, I'll let Bill answer this one.
>>Should the DECconcentrator 900MX pass it's loop test if a loopback
>>connector is put on the end of this cable?
No. Whether it's an A, B, or M port on the concentrator, if you attach
a loopback connector on it, the LED should indicate an illegal topology
error because A-A, B-B, and M-M connections are rejected.
/l
|
| 1558.2 | 100m is what we advertise | NETCAD::MELARAGNI | | Tue Jan 24 1995 20:20 | 20 |
| It is generally accepted that the max cable length for UTP is 100m. I
purposefully made this statement ambiguous because the TP-PMD spec does
not *strictly* limit the lenght to 100m. It specifies that a max cable
length is determined by its electrical characteristics, as defined by
the Structured Wiring spec (EIA/TIA-568B) and the TP-PMD spec.
But don't let me confuse you too much; we sell TP-PMD as a 100m
solution only. This cable length falls very nicely into the structured
wiring heirarchy. Besides, most cable manufacturers really only
guarantee their cable will meet '568 up to 100m.
Finally, if you have a max length UTP cable and put a loopback on it
you will have effectively doubled the length of the cable, yes? 2 x max
= too much. It won't work.
Also only S-S connections will complete, all other homogeneous connections
will be bounced (as Larry said...).
bill
|
| 1558.3 | Consistent with results..... | SCCAT::MILLER | | Wed Jan 25 1995 11:20 | 8 |
| Thanks. By hanging a loop on the end, I was looking for a simple way
of checking basic connectivity in the wiring. The wiring vendor
cert'ed the station wiring from the 110 frame to the station, but
didn't test from the DECconc 900MX cable on out. The interesting thing
is that, for closer stations, the loop test did pass (blinking yellow
LED). As I got further away, consistant with the 100m "max", the test
didn't. The final test is, of course, hooking up a system (which
wasn't available at the time).
|