[asterisk-users] Audio Dropouts During Call

Antony Stone Antony.Stone at asterisk.open.source.it
Tue Apr 3 17:32:28 CDT 2018

On Wednesday 04 April 2018 at 00:20:29, Dave Platt wrote:

> Also, check the wiring.  Check each individual RJ-45 jumper, *and* the
> in-house wiring, with a proper tester that can verify that the
> individual pairs are hooked up correctly.

Can you provide a link to such a tester?

> The problem is this:  in a telco RJ-45 cable (such as was/is often used
> for proprietary telephone systems) the individual wires are either not
> in twisted pairs, or are twisted-pairs in a 1-2 3-4 5-6 7-8 arrangement.
> These work fine for analog connections.  They're latent-death-on-wheels
> for Ethernet.

> A good Ethernet cable-pair tester can spot such things pretty quickly.

I disagree.

*Certainly*, incorrect pair terminations can cause the sort of problems 
described, however I haven't yet come across a cable tester which can identify 
that a cable correctly connected from end to end with wires {1..8} <-> {1..8} 
is in fact not correctly connected in ethernet 1-2 3-6 4-5 7-8 pairs.

All cable testers I have so far encountered will check that all wires are 
correctly connected end to end and not cross connected etc., but have no clue 
whether the wire joining pin 3 at one end to pin 3 at the other end is twisted 
together with the cable from pin 4 or pin 6.

I would be very interested to find such a tester, if you can point us at one.



"Can you keep a secret?"
"Well, I shouldn't really tell you this, but... no."

                                                   Please reply to the list;
                                                         please *don't* CC me.

More information about the asterisk-users mailing list