Bandwidth adjustment method, apparatus and system, electronic device, and readable storage medium

A bandwidth adjustment system, comprising:

• a source node and a sink node connected to the source node through at least one intermediate node, wherein
• the source node is configured to receive an adjustment command issued by a network management server, enter an adjustment mode corresponding to an Optical Service Unit (OSU), perform a first adjustment on a forward transmission bandwidth parameter of the OSU, and send a first message to an intermediate node that is downstream and adjacent to the source node in response to the first adjustment being successful;
• the at least one intermediate node is configured to receive the first message, enter the adjustment mode corresponding to the OSU, perform a second adjustment on the forward transmission bandwidth parameter of the OSU, and forward the first message to the intermediate node or the sink node that is downstream and adjacent to the at least one intermediate node in response to the second adjustment being successful;
• a sink node is configured to receive the first message, enter the adjustment mode corresponding to the OSU, perform a third adjustment on the forward transmission bandwidth parameter of the OSU, and return a second message to the intermediate node that is upstream and adjacent to the sink node in response to the third adjustment being successful;
• the at least one intermediate node is further configured to receive the second message, and return the second message to the intermediate node or the sink node that is upstream and adjacent to the at least one intermediate node;
• the source node is further configured to receive the second message, and exit the adjustment mode corresponding to the OSU;
• the at least one intermediate node is further configured to exit the adjustment mode corresponding to the OSU;
• and
• the sink node is further configured to exit the adjustment mode corresponding to the OSU.