Cable modem termination system

A cable modem termination system including a processor executing instructions, comprising:

• determining a first quantity related to uncorrectable erroneous codewords and a second quantity related to other codewords except said erroneous codewords in a data packet received by said cable modem termination system from another device via a channel;
• calculating a first metric based upon said first quantity and said second quantity;
• in response to said first metric indicating a threshold number of uncorrectable erroneous codewords over a first time duration, determining said channel as a damaged channel;
• determining a third quantity related to uncorrectable erroneous test codewords and a fourth quantity related to other test codewords except said erroneous test codewords in said test data received by said cable modem termination system from said another device via said channel;
• calculating a second metric based upon said third quantity and said fourth quantity;
• and
• in response to said second metric indicating a threshold number of correctable codewords over a second time duration, determining said channel as an available channel.