Introduction to xPON Type C Protection

Introduction to xPON Type C Protection

Type C provides redundancy for OLT (dual homing), ONU's PON ports, backbone fibers, optical splitters, and distribution optical fibers. When a fault occurs, services can be automatically switched to the functional link. After the fault is rectified, services are automatically switched back to the original link.

xPON type C protection can be deployed in two networking scenarios: single homing and dual homing.

Figure 1 shows the xPON type C protection single homing network.

Figure 1 xPON type C protection network (single homing)

Networking Mode	Advantage	Disadvantage	Scenario
Single homing	The networking mode is simple, and OLT and ONU can be managed easily.	When the OLT becomes faulty, services are interrupted. Optical fibers are deployed on the same channel and therefore two optical fibers may be broken at the same time.	This mode is used to protect important services, such as Enterprise private line services and base station services.

Figure 2 shows the xPON type C protection dual homing network.

Figure 2 xPON type C protection network (dual homing)

 

Networking Mode	Advantage	Disadvantage	Scenario
Dual homing	When the active OLT or its uplink fails, services can be switched to the standby OLT.	The networking mode is complicated and costly, and the ONU management is difficult.	This mode is used to protect a power system or Enterprise private line services and base station services.

 

On a single homing network, one ONU such as Huawei MA5626 is connected to two PON ports on an OLT, one working as the active port and the other as standby. The two ports on the OLT cannot forward packets at the same time. An automatic switching can be triggered by any of the following conditions:

• Loss of signal (LOS) occurs in the input direction.
• The ONU is offline.
• The OLT or ONU hardware is faulty.

 

On a dual homing network, two PON lines, one working as the active line and one as standby, between an ONU and two OLTs cannot forward packets at the same time. An automatic switchover can be triggered by any of the following conditions:

• Loss of signal (LOS) occurs in the input direction.
• The ONU is offline.
• The OLT or ONU hardware is faulty.
• The OLT's uplink is faulty (this condition triggers automatic switching only in the associated protection switching scenario).

 

If you want to know more information about xPON type C protection, you can contact Thunder-link.com.