[c-nsp] PA-A3-T3 FEBE and LOS

[Phil Davis]

Hello,

  I have an ATM DS3 coming through a PA-A3-T3. The last few days it 
would abruptly go down for 5-10 minutes, perhaps every 12 hours on 
average. During these times, the interface would show rapidly growing 
carrier signal loss (about 10-20/sec.) I also saw incrementing FEBE 
errors. However, neither the provider, nor a third-party transport 
provider was detecting LOS on the line. However, the far side did see a 
relatively small number of FEBE errors.
  I swapped the interface and it's been quiet for last few hours, though 
it remains to be seen if that's the last of the issue. Does this make 
sense to anybody? I don't understand why an erroring PA would detect LOS 
without LOS being present. Could it have been bouncing in and out of 
loopback?

sh run int ATM1/0:
interface ATM1/0
 no ip address
 no ip mroute-cache
 atm scrambling cell-payload
 atm framing cbitplcp
 no atm auto-configuration
 no atm ilmi-keepalive
 no atm address-registration
 no atm ilmi-enable
 no clns route-cache
end

sh diag 1:
ATM WAN DS3 Port adapter, 1 port
        Port adapter is analyzed
        Port adapter insertion time 02:39:05 ago
        EEPROM contents at hardware discovery:
        Hardware revision 2.0           Board revision A0
        Serial number     23121181      Part number    73-2432-04
        FRU Part Number:  PA-A3-T3=

        Test history      0x0           RMA number     00-00-00
        EEPROM format version 1
        EEPROM contents (hex):
          0x00: 01 5B 02 00 01 60 CD 1D 49 09 80 04 00 00 00 00
          0x10: 50 00 00 00 00 09 17 00 FF FF FF FF FF FF FF FF

sh contr atm1/0:
Slot 1:
        ATM WAN DS3 Port adapter, 1 port
        Port adapter is analyzed
        Port adapter insertion time 02:39:05 ago
        EEPROM contents at hardware discovery:
        Hardware revision 2.0           Board revision A0
        Serial number     23121181      Part number    73-2432-04
        FRU Part Number:  PA-A3-T3=

        Test history      0x0           RMA number     00-00-00
        EEPROM format version 1
        EEPROM contents (hex):
          0x00: 01 5B 02 00 01 60 CD 1D 49 09 80 04 00 00 00 00
          0x10: 50 00 00 00 00 09 17 00 FF FF FF FF FF FF FF FF

sh contr atm1/0:
Interface ATM1/0 is up
Hardware is ENHANCED ATM PA - DS3 (45000Kbps)
Framer is PMC PM7345 S/UNI-PDH, SAR is LSI ATMIZER II
Firmware rev: G153, Framer rev: 1, ATMIZER II rev: 3
  idb=0x63A1F0D4, ds=0x63A491E0, vc=0x63A572E0
  slot 1, unit 1, subunit 0, fci_type 0x005B, ticks 9682
  1200 rx buffers: size=512, encap=64, trailer=28, magic=4
Curr Stats:
  VCC count: current=32, peak=32
  AAL2 VCC count: 0
  AAL2 TX no buffer count: 0
  AAL2 RX no buffer count: 0
  SAR crashes: Rx SAR=0, Tx SAR=0
  rx_cell_lost=0, rx_no_buffer=0, rx_crc_10=0, rx_no_mem=0
  rx_cell_len=0, rx_no_vcd=313, rx_cell_throttle=0, tx_aci_err=0
Rx Free Ring status:
  base=0x3CA7C040, size=2048, write=1016
Rx Compl Ring status:
  base=0x7E4DB7E0, size=2048, read=834
Tx Ring status:
  base=0x3CF13A40, size=8192, write=2205
Tx Compl Ring status:
  base=0x0E1B3840, size=4096, read=1101
BFD Cache status:
  base=0x65F45940, size=6144, read=6140
Rx Cache status:
  base=0x64458360, size=16, write=2
Tx Shadow status:
  base=0x66691E60, size=8192, read=2191, write=2205
Control data:
  rx_max_spins=22, max_tx_count=144, tx_count=14
  rx_threshold=800, rx_count=2, tx_threshold=4608
  tx bfd write indx=0x47C, rx_pool_info=0x63A208C0
Control data base address:
       rx_buf_base = 0x0E3A6C80        rx_p_base = 0x66802E80
            rx_pak = 0x639727DC              cmd = 0x64752080
            framer = 0x60479798        framer_cb = 0x6474FB80
       framer_base = 0x3C900000     pci_pa_stats = 0x7E391900
    device_base[0] = 0x3C800000   device_base[1] = 0x3CC00000
     ssram_base[0] = 0x3CA00000    ssram_base[1] = 0x3CE00000
     sdram_base[0] = 0x3CB00000    sdram_base[1] = 0x3CF00000
     pa_cmd_buf[0] = 0x3CA7FC00    pa_cmd_buf[1] = 0x3CE7FC00
       vcd_base[0] = 0x3CA00000      vcd_base[1] = 0x3CE18000
      chip_dump[0] = 0x0E39192C     chip_dump[1] = 0x0E391A2C
   sar_buf_base[0] = 0x3CB24000  sar_buf_base[1] = 0x3CF1C000
       bfd_base[0] = 0x3CA64000      bfd_base[1] = 0x3CE00000
       acd_base[0] = 0x3CA22080      acd_base[1] = 0x3CE38240
Framer Information:
 Framing mode: DS3 C-bit PLCP
 No alarm detected
Facility statistics: current interval elapsed 682 seconds
          lcv       fbe       ezd        pe       ppe      febe      hcse
   ----------------------------------------------------------------------
 0          1         0         1         1         1         0         0

PLCP Errors:
         bipe       fbe      febe
    -----------------------------
 0          1         0         0

   lcv:  Line Code Violation
   fbe:  Framing Bit Error
   ezd:  Summed Excessive Zeros
   pe:   Parity Error
   ppe:  Path Parity Error
   febe: Far-end Block Error
   hcse: Rx Cell HCS Error
   bipe: Bit Interleave Parity (B1) Error

Thanks!
Phil