The OLT supports multiple protection switching modes for GPON lines.

GPON networks use various protection mechanisms to ensure high availability and reliability. These mechanisms are classified into different types based on their scope and functionality:

Type A :

Protects only the trunk fiber (between the OLT and the splitter).

Does not protect branch fibers (between the splitter and ONUs).

Type B :

Protects the trunk fiber but does not provide simultaneous protection for branch fibers.

Type C :

Provides full protection for both the trunk and branch fibers.

Uses redundant fibers and splitters to ensure continuity in case of a failure.

Type D :

Not a standard GPON protection type.

Since the question specifies protection for both the backbone (trunk) and branch fibers, the correct answer is Type C .

References:

HCIA Huawei ACCESS Official Documentation , Chapter: GPON Protection Mechanisms.

GPON Redundancy and Protection Schemes by Huawei.