[AusNOG] TX/RX Conventions

[john at netniche.com.au]

On 13.06.2012 07:21, Tom Sykes wrote:

> I'm interested to understand which conventions/standards (if any) are
> being used by operators to identify the TX/RX in fibre patching
> panels/trays - in environments like a meet me room or datacentre.

Hi Tom,

I'm not aware of any convention other than the "flip it if it doesn't 
work and curse shutdown-by-default policies".

Cisco appear to place TX on the "left" of the optics (first port). The 
LC connector specification chickens out from making a distinction, and 
the SFP/SFP+ specifications also don't make a commitment (they allow for 
copper and single-fibre, after all).

 From a purely logical point of view, TX should be on the "first" port 
of a group. This is because it's difficult to test for the absence of a 
signal, so if only 1 of two ports has a signal on it that should ideally 
be the first one you try.

Otherwise, you're condemning engineers everywhere to a sequence of try 
port 1, nope, try port 2 - that's a 30 second gain in productivity for 
the industry each time they plug in a patch lead :)

John