On Tue, 11 Aug 2009 18:08:39 +0100, John Rumm
wrote:
Phil Addison wrote:
I'm probably reading too much into the term 'patch'. To me it indicates
connecting sources to destinations via patch leads, as in the original
telephone exchange where someone making a call is connected to the
receiver (although in this case the sender and receiver will sometimes
be reversed). In your photo all the patch-panel sockets appear to be
In most cases there is no sender or receiver - both PABX and ethernet
are fully bidirectional with connection equally likely to be initiated
at each end.
Indeed; I should have kept to source and destination.
If I'm on the right track then, in your photo the grey cables are phone
line 'patch cords' linking your phones to the PABX at the bottom, and
the blue ones are short catx 'patch cables' linking the central network
switch to various remote computers or other network devices.
Yup. Some PABX systems may use RJ45 sockets - which means ordinary
ethernet patch cables can be used for everything. The one pictured uses
RJ11. So I simply bought a number of long RJ11 to RJ11 cables and cut
them in three - adding extra connectors to make up some shorter phone
patch leads.
Then they are RJ11 to RJ45 patch leads now?
No, RJ11 to RJ11. You can take advantage of the fact that the smaller
versions of the RJ45 (more correctly 8P8C (eight pole, eight contact)[1]
such as the RJ11, will plug into sockets with more ways and still
perform correctly.
Ahh I see. Does that mean you can't get short RJ11 to RJ11 patch leads?
Could you make them up from scratch from a length of phone cable, after
all, you must have had to crimp 4 RJ11s per 3 leads, so having 2 on
already seems a marginal benefit.
You can even plug a RJ10 (4P4C) as found on a telephone handset, into
the 6 and 8 way sockets.
Eeek!
I can't reconcile that
http://wiki.diyfaq.org.uk/index.php?...anelWiring.jpg
photo with this
http://wiki.diyfaq.org.uk/index.php?...PatchPanel.jpg one
because the spacing between the RJ45s in the 1st is much less than the
punch-down blocks in the 2nd. Why 2 rows in the second pic, or are we
seeing the rears of two patch panels? I suppose there must be a catx
wire connecting each terminator block on the rear of a patch-panel to
its corresponding RJ45 on the front?
I could do with another photo I think that shows you the patch panel
from the top. Yes the second photo is the back of the patch panel.
If you could "look through" from front to back you would see each socket
is tracked to a krone strip, and they alternate side to side to make
space for the strip of 8 punch down terminals which is wide than the
physical 8 way connector:
1 3 5
###### ###### ###### - krone strips on the back - odd numbers
_______________________
1 | 2 | 3 | 4 | 5 | 6 | - sockets on front
###### ###### ###### - krone strips on the back - even numbers
2 4 6
Aha, now I HAVE got it. The missing bit of know-how is that a krone
block is the same width as two RJ45 sockets so 2 krones one above the
other just fit in the space of the 2 RJ45s they serve. Just out of
interest, what do you mean by 'tracked'? Is it on a pcb, a film wire or
actual catx cable? Whatever it is still has to meet the catx spec.
What other explanations / photos do you think would make it a bit clearer?
Ideally a photo of a patch panel from above showing the complete route
through from a patch (or other input) lead at the front to a loom lead
at the back, plus the bit above explainning that patching does not have
to, or doesn't usually, happen on the patch-panel itself .
ok, will see what I can do.
The diagram above explains it quite nicely, and feel free to use any of
the text of my interpretation.
Thanks for the additional clarification, of an already excellent article
- its taken me from "what thef' is structured cabling all about?" to "I
think I've got it"!!
Now all we need do is get to the "where can a buy one" and the job is done!
;-)
Err... there's just the little matter of needing to move furniture, lift
carpets, floorboards everywhere!! I'll have to stick with wireless, and
maybe get some homeplugs, for the time being. But least I know what I'm
missing now!
Phil