T1 CONTROLLER LOF detected

[Muneeb89]

I saw LOF  detected and test with loopback the cards seems good, so is this issue with Telco or what else do I need to check? 

Dec 6 15:50:04.527: %CONTROLLER-5-UPDOWN: Controller T1 0/0/1, changed state to down (LOF detected)
Dec 6 15:50:06.527: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/1:1, changed state to down
Dec 6 15:50:06.527: %LINK-3-UPDOWN: Interface Serial0/0/1:1, changed state to down
Dec 6 15:50:22.527: %CONTROLLER-5-UPDOWN: Controller T1 0/0/1, changed state to up
Dec 6 15:50:24.527: %LINK-3-UPDOWN: Interface Serial0/0/1:1, changed state to up
Dec 6 15:50:36.651: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/1:1, changed state to up
Dec 6 15:50:37.643: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/1:1, changed state to down
Dec 6 15:50:39.691: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/1:1, changed state to up
Dec 6 15:52:08.527: %CONTROLLER-5-UPDOWN: Controller T1 0/0/1, changed state to down (LOF detected)
Dec 6 15:52:10.527: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/1:1, changed state to down

[Georg Pauwen]

Hello,

I would say in 99 percent of the cases, Loss of Frame is TELCO related. You could try to shut/no shut the controller, or unplug and plug back in the physical cable, but get with the Telco asap...

Also, make sure the settings below match with the TELCO side:

clock source {internal | line}
linecode {ami | b8zs | hdb3}
cablelength {long | short}

[Muneeb89]

thanks for your help, we change the T1 card from both side resolved the issue