Analyse Interface Serial

Bonjour,

j'ai un problème d'interfece E1, car sur mon routeur cisco je fais la cmd "show logging" et là l'interce E1 2/0 elle est UP/DOWN..
je fais un "show interface S2/0:1"

Serial2/0:1 is up, line protocol is up
Hardware is Multichannel E1
Description: Lien vers Bureau de Paris 2Mo
Internet address is 172.16.7.1/24
MTU 1500 bytes, BW 2000 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP Open
Open: IPCP, CDPCP, crc 16, Data non-inverted
Keepalive set (10 sec)
Last input 00:00:37, output 00:00:05, output hang never
Last clearing of "show interface" counters 3w2d
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 876
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/15/16 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1500 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
2313900 packets input, 1456001225 bytes, 0 no buffer
Received 0 broadcasts, 2470 runts, 0 giants, 0 throttles
2855 input errors, 116 CRC, 0 frame, 0 overrun, 0 ignored, 48 abort 2213113 packets output, 1494762337 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
694 carrier transitions
no alarm present
Timeslot(s) Used:1-31, subrate: 64Kb/s, transmit delay is 0 flags
--------------------------
ce que j'ai pu remarqué c'est qu'il a bc d'erreur on input ! quelqu'un peut me m'aidre pour trouver la cause de ce problème ?

Merci à vous