Modules for optical time-domain reflectometry (OTDR) are connected via at least one fiber link of a fiber optic communication network. The modules can perform OTDR operations on the at least one fiber link. In addition, the modules can establish an inter-node communication channel between each other on the at least one fiber link. The channel allows the OTDR modules to synchronize their OTDR operations and to exchange information, such as OTDR traces, between each other.