[Asterisk-Users] Forklift a 2000 phone PBX

[tmassey at obscorp.com]

asterisk-users-bounces at lists.digium.com wrote on 03/24/2005 06:42:24 PM:

> Does anyone know how to qualify existing Cat3 wiring for use as a LAN?

That's easy:  Cat3 is able to handle 10Mbit.  So if the wire truly is 
Cat3, you can use 10Mbit switches and be in good shape.

Now, how do you know if the wiring is truly Cat3?  Just because the raw 
wire is Cat3 means nothing if they wrapped it around a few fluroescent 
lights...  ;)

Your best bet would be to certify the wiring.  A used scanner you bought 
on eBay would be fine:  there are plenty of Cat5 scanners around that 
people are replacing with Cat6 scanners.  I like the old Pentascanners 
(used to be Microtest, now owned by Fluke).  They will also certify for 
Cat 3.

The problem is, most phone wire is: A) Terminated into 66 blocks, B) Not 
ran with data requirements in mind, and C) Often terminated as two lines 
per wire.  For A, you have to re-terminate all of the lines, for B, you 
may have to re-run some (or even most) of the lines because of quality or 
length issues, and for C you may have to run fully half of the lines again 
because they may want two jacks in an office like there is now, but 
there's only one wire going to that office.  You could use those 
mini-switch-in-a-jack thingies, but they are usually more expensive than 
it would cost to run more wire!  :)

In short, unless the phone wire is just a few years old at the *oldest*, 
assume the worst:  the wire will not work out for you.

That, by the way, is why *all* wiring I have done for my clients is all 
done Cat5 (or higher) into patch panels.  I then use a patch panel wired 
to a 66 or (usually a) 110 block for connection to the phone system and 
plug into it like you would an Ethernet hub.  That way, when they are 
ready for VoIP (or just want to use a data jack for phone or vice-versa), 
it is idiot simple.

Tim Massey