DSL

Red

No DSL sync, errors detected, or signal quality < 2db. Call your carrier.

DS1

Red

Premise equipment T1 issue. Call your vendor.

ALM

Red / Yellow

Loss of signal from carrier / Loss of signal to carrier 

ESF/SF

Yellow / Green

ESF is most common so expect Yellow

B8ZS/AMI

Yellow / Green

ESF is most common so expect Yellow

LLB

Green / Yellow

 Active remote loopback toward this card. / This device is in loopback.