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Fail in interface cooperation caused by dismatch in parameters for E1 between NE40E and Cisco Routers

Publication Date:  2014-10-31 Views:  79 Downloads:  0
Issue Description

In one site with boarder router replacement, the NE40E-X8(V6R1) need inter-operate with Cisco Router on E1 interface. During link integration, it is found that both physical and link layer

protocol state are in Down status.

Handling Process

1. Transmission or link problem
2. Dismatch in Channel mode between peers
3. Dismatch in Coding or frame format between peers

4. Dismatch in link layer protocol between peers

5. Dismatch in CRC4 mode between Peers

Root Cause

Dismatch in interface parameters


1.Check link and Transmission issue:

  Step1: Physical Loop for remote in DDF in both sites, physical port changed to up,so the transmission is ok;

  Step2: Loop for remote with soft mode in peer interfaces, ( under controller E1 mode, input

command of loopback remote),physical port changed to up,so the link is ok;


2. Check E1 Channel mode: both peers set with channel mode, and all the timeslots are binding



3.Check E1 Coding: both peers are configured in HDB3 ( default mode in HW and Cisco Box).


4.Check frame mode: Cisco in default with CRC4, while HW in default mode of Non-CRC4.

Cisco interface status:
E1 0/1/0 is down.
Applique type is Channelized E1-balanced
Transmitter is sending remote alarm.
Receiver has loss of frame.
alarm-trigger is not set
Version info Firmware:20100222,FPGA:13,spm_count = 0
Framing is CRC4,LineCodeis HDB3, Clock Source is Line.
Data incurrent interval (15 seconds elapsed).
0 Line Code Violations,0 Path Code Violations
0 Slip Secs 0FrLossSecs 0LineErrSecs, 0DegradedMins
0 Errored Secs, 0 Bursty Err Secs,0 Severely Err Secs,15 Unavail Secs
Data in Interval 1:
0 Line Code Violations,18 Path Code Violations
0 Slip Secs,0 Fr Loss Secs,0 Line Err Secs,0 Degraded Mins
0 Errored Secs,0 Bursty ErrSecs,0 Severely Err Secs,900 Unavail Secs
Change HW frame format to CRC4, interface physical status is UP, but link layer protocol is still down.

5.Check link layer protocol, Cisco is HDLC by default, HW is PPP by default.

  Change HW interface to HDLC mode, and protocol status is still down;

  Change both sites to PPP, protocol status is still down.

  Cisco have private implement of HDLC(Called cisco-hdlc), it is suggested to use PPP between

  Cisco and HW when cooperate with each other.


6. After set both interfaces to PPP, checking the CRC, it is found HW in CRC32, while Cisco in CRC16. Change HW CRC32 to CRC16, Protocol status change to be UP.



When different vendors routers cooperate with each other, there are many parameters that may influence the cooperation, therefore it need to be checked one by one. Here attached the final

right configuration(Need change cisco interface to PPP encapsulation)

Controller E1 1/1/0
Channel-set 0 timeslot-list 1-31
Description to-[Peoples]
Undo shutdown
frame-format crc 4
Clock slave
Interface Serial1/1/0:0
crc 16