why haven't ethernet connectors changed?

Deepak Jain deepak at ai.net
Fri Dec 21 00:09:36 UTC 2012


>
> There could also be some valid technical reasons:
> 1. The conductors really can't get any thinner.  In fact, with Cat6A,
> they're somewhat thicker than Cat5E.
> 2. I would also think that the conductors/pins really can't get much
> closer together inside the connector shell, without cross-talk becoming
> more of a problem.  I don't have any technical data to back this up at
> the moment, but it seems reasonable.
> 3. If assertions 1 and 2 are true, then the cable really can't get any
> thinner either.  Again, if you look at Cat6A cable (especially shielded
> Cat6A), it is significantly thicker than Cat5E.

I'll chime in here. With POTS, where essentially each "circuit" is 
identical in capacity and usage type, the only way to improve density is 
via the physical media -- and even then, you are still limited by 
conductor sizes.

With Ethernet, you've seen an evolution from 10MB/s to 10Gb/s. This begs 
the question of what density you need, and against uh, say, 1000x 
improvement in capacity, what meaningful change could you make in terms 
of connector density? Even 10:1 is meaningless noise against a speed 
improvement at the circuit layer.

Lots of Ethernet is still run identically to the way POTS lines are run. 
Large cable pulls back to central wiring closets. This is part of the 
problem.

If one chose to adopt a model where connections are 
multiplexed/aggregated closer to their source and the aggregation brings 
with it higher signalling speeds --- [Think top-of-rack switching vs 
end-of-row switching]. I'm not saying its useful for everyone, but the 
idea is that if density were your issue, there are much better physical 
ways to manage the data requirements than the POTS model.

In our office spaces (albeit in data center buildings) we have 
individual rooms with 24/48 port ethernet switches dedicated to the 
room. These uplink via a redundant pair of fiber. This represents lots 
of copper not making it out to the end-of-hall wiring closet which is 
now just a passive WDM fiber aggregation point. [Consummate savings in 
copper, weight, complexity, and labor -- at no significantly higher 
hardware failure risk].

Fiber has solved the density problem in a way that copper hasn't and 
this may be in part to reduced concerns about cross-talk and thinner media.

So with so many options to reduce the amount of copper you need, and the 
use of fiber to move large amounts of connectivity much longer distances 
and at higher speeds, why would you still want to implement a wiring 
closet with 2000 RJ-45s anymore -- and if you have the justification, 
what's another 5 square feet to make it happen against the costs you're 
already incurring?

DJ



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