Hi everybody!
In this theme, I continue to explain downstream network protection. Now, I want to explain the type C dual-homing protection.
Nowadays, customers want reliable services. They have little tolerance for service interruptions. Especially business users. Because of that, we must have protection in downstream, upstream protection and redundancy components in OLT.
GPON downstream networking protection has A, B, C and D modes. Current downstream networking protection is type B single/dual-homing protection and type C single/dual-homing protection. Now, I will shortly explain the type C dual-homing protection. After that, I will show commands for configuration this protection.
Type C dual-homing protection is a very expensive solution, a very complex solution for building and maintenance. But, this solution has the best downstream network protection.
This network protection has 2 OLTs (2 chassis, 2 slots, 2 service boards, 2 PON ports), 2 backbone fibers, 2 optical splitters and 2 branch fibers. Only type C protection has backbone fiber protection and branch fiber protection.
Type C dual-homing protection has 2 different PON ports on the different boards and OLTs. One PON port is active and this is an active link. The second PON port is standby and this is the standby link. This protection can automatically switch from active to standby link when there is some problem with the active link.
Automatic switching can be triggered when one of the following conditions is met:
LOS occurs in the input direction,
the ONUs are offline,
the OLT (chassis, slot, service board, PON port) and ONU hardware is faulty, and
the OLT`s uplink is faulty.
Next figure show type C dual-homing protection:
When the active line is interrupted due to a backbone/branch fiber or component (such as optical splitter, PON port, GPON board, slot or chassis of OLT), the ONU will switch services to the standby line. If the OLT`s uplink is the faulty, system will automatically switch from active OLT to standby OLT, too.
When the primary line or uplink fix, the system will automatically start to switch services from standby to the primary line (active line). The OLT sends an automatic switchback message and the switchback time to the ONU.
Advantage: protection in 2 OLTs (2 chassis, 2 slots, 2 service boards, and 2 PON ports) and good network protection – backbone and branch fibers, and optical splitters.
Disadvantage: very expensive solution and very complex solution for building and maintenance.
And the end, you can see the configuration on the active and standby OLT. All profiles on these ONUs must be the same. TEST1 is the active OLT, TEST2 is the standby OLT. Active and standby OLT PON ports are 0/1/1 and ONTID is 0.
1. Configuration on the active OLT:
TEST1(config)#interface gpon 0/1
TEST1(config-if-gpon-0/1)#ont add 1 0 sn-auth xxxxx snmp ont-lineprofile-id 10
TEST1(config-if-gpon-0/1)#quit
TEST1(config)#protect-group1 protect-target gpon-uni-ont workmode dual-parenting
TEST1(protect-group-1)#protect-group member port 0/1/1 ont o role work
On the active OLT, there is no command for enable protection group. After a working member is added to the protection group, the protection group automatically enable.
2. Configuration on the standby OLT:
TEST2(config)#interface gpon 0/1
TEST2(config-if-gpon-0/1)#ont add 1 0 sn-auth xxxxx snmp ont-lineprofile-id 10
TEST2(config-if-gpon-0/1)#quit
TEST2(config)#protect-group1 protect-target gpon-uni-ont workmode dual-parenting
TEST2(protect-group-1)#protect-group member port 0/1/1 ont o role protect
TEST2(protect-group-1)#protect-group enable
3. Commands for display the protection group on the active and standby OLTs:
TEST1(config)#display protect-group 1
TEST2(config)#display protect-group 1
4. Commands for delete the active OLT protection configuration:
TEST1(protect-group-1)#undo protect-group member port 0/1/1 ont o
TEST1(config)#undo protect-group 1
5. Commands for delete the standby OLT protection configuration:
TEST2(protect-group-1)#protect-group disable
TEST2(protect-group-1)#undo protect-group member port 0/1/1 ont o
TEST2(config)#undo protect-group 1
Thank you!
