Systems and methods for signal communication over an optical link are described. One aspect includes receiving a source CONFIG1 signal from a DP master device and a sink CONFIG1 signal from a sink terminal. The source and sink CONFIG1 signals are analyzed. It is determined whether a signal transmission mode is a DP protocol. For a DP protocol, a pair of source AUX signals is received from the DP master device. A pair of sink AUX signals is received from the sink terminal. Communication resource contention between the source and sink AUX signals is identified. A communication direction of the communication resources is transitioned to give the source AUX signals precedence over the sink AUX signals. The source AUX signals are transferred to the sink terminal via the communication resources. The direction of the communication resources is again transitioned. The sink AUX signals are transferred to the DP master device.