A communication system comprises a plurality of subscriber lines that are bonded to provide a bonding group, referred to as the “primary bonding group.” A data stream comprising a plurality of data packets is transmitted to a port, referred to as the “primary port,” of a network termination unit (NTU) coupled to each subscriber line of the primary bonding group, and a bonding engine of the NTU fragments the data packets for transmission across the bonding group. Logic, referred to as “link state awareness (LSA) logic,” is configured to monitor at least one communication parameter indicative of the communication performance of the bonding group. If the measured communication performance is within a specified range, the LSA logic disables the primary port. Such action signals a switching element to switch communication to another NTU that is coupled to one or more other subscriber lines for backing up the primary bonding group. Thus, communication is switched to a backup channel based on the measured performance parameter before a complete failure of the primary bonding group occurs.