Доброго времени суток, друзья!
Cisco AS5350 соединена с АТС Hicom 350H по ISDN PRI.
С переодичностью в 2-3 минуты пробегают ошибки по Q921.
Побороть никак не можем. В чем могут быть причины? У кого какие мысли?

debug ISDN Q921

*Jul 30 10:47:19.131: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:47:29.127: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:47:29.127: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:47:39.127: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:47:39.127: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:47:39.127: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:47:39.131: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:47:49.131: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:47:49.135: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:47:49.135: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:47:49.139: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:47:59.139: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:47:59.143: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:48:09.143: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:48:09.143: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:48:09.143: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:48:09.151: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:48:19.143: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:48:19.143: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:48:29.143: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:48:29.143: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:48:29.143: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:48:29.147: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:48:39.147: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:48:39.151: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:48:49.151: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:48:49.151: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:48:49.151: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:48:49.155: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:48:59.151: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:48:59.151: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:49:09.151: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:49:09.151: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:49:09.151: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:49:09.155: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:49:14.459: ISDN Se3/0:15 BKHL Q921: Net TX -> DISCp sapi=0 tei=0
*Jul 30 10:49:14.467: ISDN Se3/0:15 BKHL Q921: Net RX <- UAf sapi=0 tei=0
*Jul 30 10:49:14.467: ISDN Se3/0:15 BKHL **ERROR**: brl_rcv_pak: DL_ERROR_RESP_BRL_SM_WRITE
*Jul 30 10:49:14.591: ISDN Se3/0:15 BKHL Q921: L2_EstablishDataLink: sending SABME
*Jul 30 10:49:14.591: ISDN Se3/0:15 BKHL Q921: Net TX -> SABMEp sapi=0 tei=0
*Jul 30 10:49:14.591: ISDN  **ERROR**: bk_sm_rcv_callback: Unable to match channel ID 0x0
*Jul 30 10:49:14.655: ISDN Se3/0:15 BKHL Q921: Net RX <- UAf sapi=0 tei=0
*Jul 30 10:49:16.039: ISDN Se3/0:15 BKHL Q921: L2_EstablishDataLink: sending SABME
*Jul 30 10:49:16.039: ISDN Se3/0:15 BKHL Q921: Net TX -> SABMEp sapi=0 tei=0
*Jul 30 10:49:16.047: ISDN Se3/0:15 BKHL Q921: Net RX <- UAf sapi=0 tei=0
*Jul 30 10:49:26.051: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:49:26.051: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:49:26.051: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:49:26.055: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:49:36.055: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:49:36.059: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:49:36.059: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:49:36.063: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:49:46.063: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:49:46.067: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:49:49.707: ISDN  **ERROR**: bk_sm_rcv_callback: Unable to match channel ID 0x0
*Jul 30 10:49:51.347: ISDN Se3/0:15 BKHL Q921: L2_EstablishDataLink: sending SABME
*Jul 30 10:49:51.347: ISDN Se3/0:15 BKHL Q921: Net TX -> SABMEp sapi=0 tei=0
*Jul 30 10:49:51.359: ISDN Se3/0:15 BKHL Q921: Net RX <- UAf sapi=0 tei=0
*Jul 30 10:49:56.087: ISDN Se3/0:15 BKHL Q921: Net TX -> DISCp sapi=0 tei=0
*Jul 30 10:49:56.095: ISDN Se3/0:15 BKHL Q921: Net RX <- UAf sapi=0 tei=0
*Jul 30 10:49:56.099: ISDN Se3/0:15 BKHL **ERROR**: brl_rcv_pak: DL_ERROR_RESP_BRL_SM_WRITE
*Jul 30 10:49:57.883: ISDN  **ERROR**: bk_sm_rcv_callback: Unable to match channel ID 0x0
*Jul 30 10:49:57.883: ISDN Se3/0:15 BKHL Q921: L2_EstablishDataLink: sending SABME
*Jul 30 10:49:57.883: ISDN Se3/0:15 BKHL Q921: Net TX -> SABMEp sapi=0 tei=0
*Jul 30 10:49:57.931: ISDN Se3/0:15 BKHL Q921: Net RX <- UAf sapi=0 tei=0
*Jul 30 10:49:59.067: ISDN Se3/0:15 BKHL Q921: L2_EstablishDataLink: sending SABME
*Jul 30 10:49:59.067: ISDN Se3/0:15 BKHL Q921: Net TX -> SABMEp sapi=0 tei=0
*Jul 30 10:49:59.079: ISDN Se3/0:15 BKHL Q921: Net RX <- UAf sapi=0 tei=0
*Jul 30 10:49:59.187: ISDN  **ERROR**: bk_sm_rcv_callback: Unable to match channel ID 0x0
*Jul 30 10:50:00.715: ISDN Se3/0:15 BKHL Q921: L2_EstablishDataLink: sending SABME
*Jul 30 10:50:00.715: ISDN Se3/0:15 BKHL Q921: Net TX -> SABMEp sapi=0 tei=0
*Jul 30 10:50:00.727: ISDN Se3/0:15 BKHL Q921: Net RX <- UAf sapi=0 tei=0
*Jul 30 10:50:10.727: ISDN Se3/0:15 BKHL Q921: Net TX -> RRp sapi=0 tei=0 nr=0
*Jul 30 10:50:10.727: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0
*Jul 30 10:50:10.727: ISDN Se3/0:15 BKHL Q921: Net TX -> RRf sapi=0 tei=0 nr=0
*Jul 30 10:50:10.731: ISDN Se3/0:15 BKHL Q921: Net RX <- RRf sapi=0 tei=0 nr=0
*Jul 30 10:50:20.727: ISDN Se3/0:15 BKHL Q921: Net RX <- RRp sapi=0 tei=0 nr=0

===========================================

sh isdn status  
Global ISDN Switchtype = primary-net5

%Q.931 is backhauled to BACKHAUL 0x0001 on DSL 0. Layer 3 output may not apply

ISDN Serial3/0:15 interface
        ******* Network side configuration *******
        dsl 0, interface ISDN Switchtype = primary-net5
        L2 Protocol = Q.921 0x0000  L3 Protocol(s) = BACKHAUL 0x0001
    Layer 1 Status:
        ACTIVE
    Layer 2 Status:
        TEI = 0, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
    Layer 3 Status:
        0 Active Layer 3 Call(s)
    Active dsl 0 CCBs = 0
    The Free Channel Mask:  0x8000001F
    Number of L2 Discards = 0, L2 Session ID = 169
    Total Allocated ISDN CCBs = 0

=========================================
sh controller e1
E1 3/0 is up.
  Applique type is Channelized E1 - balanced
  No alarms detected.
  alarm-trigger is not set
  Version info of slot 3:  HW: 1032, PLD Rev: 7
  Framer Version: 0x9

Manufacture Cookie Info:
EEPROM Type 0x0001, EEPROM Version 0x01, Board ID 0x03,
Board Hardware Version 4.8, Item Number 73-3996-05,
Board Revision A1, Serial Number JAE11474BPD,
PLD/ISP Version <unset>,  Manufacture Date 24-Nov-2007.

  Framing is NO-CRC4, Line Code is HDB3, Clock Source is Line.
  Data in current interval (427 seconds elapsed):
     0 Line Code Violations, 0 Path Code Violations
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
  Total Data (last 24 hours)
     179447 Line Code Violations, 4617 Path Code Violations,
     5 Slip Secs, 0 Fr Loss Secs, 6 Line Err Secs, 0 Degraded Mins,
     3 Errored Secs, 0 Bursty Err Secs, 35 Severely Err Secs, 0 Unavail Secs