QSFP-100G-SR4-S, fiber cable polarity

[costaspal]

Hello everyone

I have to purchase a patch-cable to connect two QSFP-100G-SR4-S transceivers, but I'm asked about the polarity of the MPO cable and I cannot find anything in the transceivers' datasheet.

Polarity A or B is the supported one ?

Thanx, in advance

Costas

[Flavio Miranda]

Hello @costaspal 

https://blog.leviton.com/fiber-optic-polarity-101-b-polarity

[costaspal]

NOT an LC or SC type, connector !

Thanx anyway

[balaji.bandi]

It straight cable should work as expected, you only Twist TX and RX, when the ports not coming up or when they go via different comms rooms or patch pannels.

MM cable check the details here :

https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/datasheet-c78-736282.html

[costaspal]

MPO type cables are 'fixed'.   No way to 'twist' RX/TX.

Thanx anyway

[costaspal]

Thanx anyway

[balaji.bandi]

yes i know - i have mentioned in Generic for TX and RX

that is the reason i have mentioned reference guide that uses (MPO-12 (12 fibers))

So make sure you have presentation correctly other side when you using.

https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/high-density-fiber-patch-mpo-ds.html

[costaspal]

In this "Cisco High-Density Fiber Patch Panel, Simplex, MPO and Breakout Cables Portfolio Data Sheet" document, although 'polarity' is not mentioned anywhere, I noticed all "MPO – MPO Multi Mode" cables part-numbers (Table 13) are TYPE B.

I assume this is the 'polarity' I'm looking for, to directly connect two switches via QSFP-100G-SR4-S transceivers.

Thanx

[balaji.bandi]

As i have mentioned before depends on where you looking to connect, if other side have same presentation you can connect.

Hope both above documents have clear information - when you connect end to end.

If you looking breakout cable then you need to looks for the same presentation.