How to connect SFP J4859C in SM?

[Mārtiņš]

Hello!

I'm little bit stuck in testing SFP modules J4859C, so I can't get my switches Aruba 2920-24G and Aruba 2530-8G connected over single mode fiber. I was unable to find how to correctly set up patch cords to SFP module, so I tried to test combinations by changing single fiber on single side one by one and vice versa but it does not work :). What should be the right pinout for this module in single mode set up?

[parnassus]

Can you test directly using just only a single LC/LC fiber optic Patch Cord beetwen SW1 and SW2?
Generally it is sufficient to cross the patch cord (LC1 Tx -> LC2 Rx and LC1 Rx <- LC2 Tx)...or, in case of fiber optic distribution cabling, cross just one side of the uplink.

[Mārtiņš]

So you mean it should work in setup like in attached picture?

[parnassus]

Where is the other lead? (I mean: shown there is only one lead - Tx to Rx or the other - not two).

[Mārtiņš]

Ok, got the idea, will get another one patch and test it in that way :). Thanks in advance, 

[parnassus]

Pay attention that you can have a fiber optic distribution system (Fiber Optic Cables interconnecting Fiber Optic Patch Panels) that is partially or totally:

• Straight (Tx connector on one end is connected to Tx connector on the other end and vice-versa)
• Crossed (Tx connector on one end is connected to Rx connector on the other end and vice-versa)

So when you interconnect two Transceivers through a fiber optic distribution system you should know if you need to cross the Fiber Optic Patch Cable Tx/Rx into Rx/Tx (in case of Straight) or not (in case of Crossed) in just one end.

A complication sums up when using specifically a LC<-->LC Fiber Optic Patch Cable: since LC connectors (differently from SC/ST styled connectors) can't be "reveresed" on the LC Transceiver or LC Patch Panel ends...you are forced to use a factory crossed LC<-->LC Fiber Optic Patch Cable if you are working with a Straight distribution system (So, as example: LC Transceiver <-- LC/LC Straight Patch Cable --> LC Connector on Patch Panel <-- Straight FO cabling --> LC Connector on Patch Panel <-- LC/LC Crossed Patch Cable --> LC Transceiver).

So when you perform a LC Transceiver to LC Transceiver direct interconnection through a LC<-->LC Fiber Optic Patch Cable...this one should be necessarily already crossed.

With LC<-->SC (or ST) you have more options because the SC (or ST) Tx/Rx ends can be easily crossed if required.