Issue Description
Customer wants to connect a new link between Huawei NE80 and JM320 router using STM-1 fiber link. The line protocol is always down.
Handling Process
We have to modify the configurations of pos interface as follows:-
interface Pos6/0/0
clock slave
flag j0 sonet 1
frame-format sonet
flag c2 207
undo scramble
description "Connected to Transworld (International Exit)"
mtu 4474
undo shutdown
ip address 221.132.112.206 255.255.255.252
Physical interface: so-1/0/3, Enabled, Physical link is Up
Interface index: 140, SNMP ifIndex: 178
Description: Callmate-STM-TWIP2083-27-Jun-07
Link-level type: PPP, MTU: 4474, Clocking: Internal, SONET mode, Speed: OC3, Loopback: None, FCS: 16,
Payload scrambler: Enabled
Device flags : Present Running
Interface flags: Point-To-Point SNMP-Traps Internal: 0x4000
LCP state: Down
NCP state: inet: Not-configured, inet6: Not-configured, iso: Not-configured, mpls: Not-configured
CHAP state: Closed
CoS queues : 8 supported, 4 maximum usable queues
Last flapped : 2007-06-27 14:35:09 UTC (00:09:33 ago)
Input rate : 0 bps (0 pps)
Output rate : 72 bps (0 pps)
SONET alarms : None
SONET defects : None
Logical interface so-1/0/3.0 (Index 80) (SNMP ifIndex 37)
Flags: Hardware-Down Point-To-Point SNMP-Traps Encapsulation: PPP
Protocol inet, MTU: 4470
Flags: Protocol-Down
Addresses, Flags: Dest-route-down Is-Preferred Is-Primary
Destination: 221.132.112.204/30, Local: 221.132.112.205, Broadcast: 221.132.112.207
The configurations of flag c2 207 and j0 1 are done after getting the configurations of J-M320. But still the link protocol does not go UP because there is a parameter mismatch as that of FCS (Frame check sequence). We did not have any option in Huawei to configure FCS in pos interface but in J-M320 we can change FCS value to 16 or 32. Huawei NE80 negotiate with J-M320 on FCS=32.
After this modification on J-M320 the link protocol is UP and problem is resolved.
Root Cause
We have checked many parameters and found that there are some parematers which are different bydefault in both Huawei and J-router. We need to change some paremeters of SONET to enable the link protocol UP.