Showing results for 
Search instead for 
Did you mean: 

troubleshooting fiber

Level 1
Level 1

we just had a new circuit install at a remote data center and from what I can tell there is a big difference between what the provider is transmitting vs what I'm receiving

Provider Edge          

    Laser output power                        :  -2.13 dBm

    Receiver signal average optical power     :  -7.52 dBm

Customer Edge

  Transceiver Tx power                      = -3.5 dBm

  Transceiver Rx optical power              = -7.3 dBm

In comparison to another active circuit of mine what the provider is transmitting and I'm receiving is much closer in value.

Is this anything to worry about?   The circuits are up but wanted to make sure.

5 Replies 5

Tom Randstrom
VIP Alumni
VIP Alumni

Can you provide some details regarding the optical transceiver that you have installed in your equipment?  What type of fiber are you connecting to (singlemode or multimode)? Are these the same for the other circuit you are comparing to? 


singlemode throughout and on my side i'm using the following


provider is using Juniper router

Juniper brand 10G-LR

The two receive values, -7.52 & -7.3 dbm fall comfortably within the 10G XFP's receiver's operating range; so the link should operate properly. 

Is your equipment and the providers equipment installed in the same facility? What is the estimated length of the link?

If the LR is long range and the SR is short range, shouldn't they match on both sides?

Sent from Cisco Technical Support iPad App

I assume the link is configured for 10G Ethernet (vs OC192 POS), correct? 

The Cisco XFP-10GLR-OC192SR optical transceiver is compliant to the IEEE 10Gbps Ethernet Long-Reach standard and the OC-192 Short-Reach standard.  The Junipter 10G-LR support the 10Gbps Ethernet Long-Reach standard.  If you are running the link at 10Gpbs Ethernet, then they are matched on both sides.

I hope this helps!