[c-nsp] Serial link CTS=down link UP

[Marcelo Zilio]

Hi,

Has anyone seen this in serial interfaces before?
Link is UP and traffic is going through, however router shows CTS=down
besides a lot CRCs/Input Errors.
It doesn't make sense to me the parameter which should advise that the link
is "ready to go" is DOWN while there is traffic on it.
Users are complaining some application are slow.

The router is a Cisco 2811 IOS 12.4(15)T10.

Router#sh int s0/1/0
Serial0/1/0 is up, line protocol is up
  Hardware is GT96K Serial
  MTU 1500 bytes, BW 256 Kbit/sec, DLY 20000 usec,
     reliability 255/255, txload 40/255, rxload 42/255
  Encapsulation FRAME-RELAY IETF, loopback not set
  Keepalive set (10 sec)
  CRC checking enabled
  LMI enq sent  48, LMI stat recvd 48, LMI upd recvd 0, DTE LMI up
  LMI enq recvd 0, LMI stat sent  0, LMI upd sent  0
  LMI DLCI 0  LMI type is ANSI Annex D  frame relay DTE  segmentation
inactive
  FR SVC disabled, LAPF state down
  Broadcast queue 0/64, broadcasts sent/dropped 7/0, interface broadcasts 0
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters 00:07:55
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: dual fifo
  Output queue: high size/max/dropped 0/256/0
  Output queue: 0/128 (size/max)
  30 second input rate 43000 bits/sec, 68 packets/sec
  30 second output rate 41000 bits/sec, 78 packets/sec
     34746 packets input, 2956769 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     602 input errors, 602 CRC, 433 frame, 107 overrun, 0 ignored, 323 abort
     43237 packets output, 3308125 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions
     DCD=up  DSR=up  DTR=up  RTS=up  *CTS=down*

 Thanks,