A bandwidth sensing system operates to sense the existence of additional bandwidth available for transmitting data over a best effort communication. The operations include receiving an original block of data from a transmitting node and calculating error correction data based on the original block of data. The original block of data and the error correction data is then transmitted toward a receiving node. The data may be simply appended or, the entire block may be modified during the error correction data process. When the original block of data and error correction data is received at the receiving end associated with the receiving node, the data is analyzed to determine if any errors occurred in the transmission. If so, the error correction data is used to maintain the integrity of the transmitted data by restoring the original block. However, if no errors are detected, because the error correction data inherently requires the transmission of additional data, the receiving end can conclude that additional bandwidth is available over the channel. Thus, the transmitting node can be notified of the available bandwidth so that additional bandwidth can be utilized on subsequent transmissions.