Re: ISDN wiring

Jay_Feldis@logitech.com
15 May 95 18:34


[Text item: Re: ISDN wiring]
OriginalPath:
You can get away with low-grade wiring for a limited distance. My local
Telco has advised that a good quality twisted pair type wire be used to
make sure you maintain the signal over any distance (ie - wall outlet to
outsude of the building). My NT1 manual specifies minimum catagory 3
cable.

Some telephone station wire is poorly made and does not provide twisted
pairs (or twisted enough) to provide a good transmission line for the
high data rate signal. This is good enough for an analog phone
extension, but could cause problems for ISDN.
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Regarding the bandwidth discussion:
I recently set up a commercial video conferencing system which uses ISDN.I
found it very interesting that the lines from the Dmark (and for all I know
the lines to the Dmark) to the ISDN outlet in the wall were standard 2
conductor telephone wire. These two wires carried carried both "B" channels
and the "D" channel. The "B" channels being 64K each. This begins to make
sense in light of this discussion.

CU

Don Johnson
DisplaySubject: Re: ISDN wiring