sfp model for st links

[suthomas1]

Hello,

In one of the links using fibre connections, part of it uses an SC-ST fibre to get the two devices
connected. Is there any specific type of sfp on that needed to be used for this to work properly.
The device-to-device distance is roughly around 16-20Km mark.
This works well when connected all through with SC-SC & SC-LC fibre & 10Gbase-LR sfp . however, when one of the hops is replaced with a different SC-ST path connection, the link doesn't come up again.

Appreciate all help.
Thanks.

[Marvin Rhoads]

The phyical form factor of an intermediate link or patch point does not change the link requirements. Generally speaking as long as you have transmit to receive (and vice versa) and meet the link loss budget you can use any one type - or serveral patch types - along the path.

The most commmon issues are mismatch (swap) of Tx and Rx and exceeding the loss budget via bad physical connections. You should be able to use Digital Optical Monitoring (DOM) to see what leves you are getting. i.e. "show interface <interface number> transceiver details".

[Philip D'Ath]

You might find your LC leads are 50 microns and the SC ones are 75 microns (just guessing).

Whatever - you want to stick to using only one fibre size. These days 50 micron is more common. In the past 75 microns was more common.

[Jonnathan London]

As the guys said above, firstly you need to check your connections and confirm if the power budget is acceptable for the link. Besides, at present 10G optic modules are LC interface. For your condition, an optical adapter maybe helpful to achieve SC-ST path connection.