DBA (Dynamic Bandwidth Allocation) :

DBA is a mechanism in GPON networks that dynamically allocates upstream bandwidth among ONUs based on their traffic demands.

Functions of DBA :

Improves upstream bandwidth utilization : DBA ensures efficient use of the limited upstream bandwidth by allocating it dynamically to ONUs as needed.

Does not increase total upstream bandwidth : The total upstream bandwidth of a PON port is fixed and determined by the hardware. DBA optimizes how this bandwidth is used.

Does not affect downstream bandwidth : Downstream bandwidth is shared via broadcasting and is not managed by DBA.

Does not add more ONUs : The number of ONUs supported by a PON port depends on hardware capacity, not DBA.

Why C?

DBA improves the efficiency of upstream bandwidth utilization by dynamically allocating resources.

Thus, the correct answer is C .

HCIA Huawei ACCESS Official Documentation , Chapter: GPON DBA Mechanism.

GPON Dynamic Bandwidth Allocation by Huawei.