Systems and methods for communicating vectoring streams in multi-card vectoring groups

A network access point, comprising:

• a switching element;
• a ring connection;
• a first line card coupled to the switching element, the ring connection, and a first plurality of subscriber lines, the first line card configured to cancel crosstalk affecting first symbols communicated across the first plurality of subscriber lines based on a vectoring stream carried by the ring connection, thereby providing first crosstalk-compensated symbols, the first line card further configured to insert the first symbols into the vectoring stream and to transmit the first crosstalk-compensated symbols to the switching element;
• a second line card coupled to the switching element, the ring connection, and a second plurality of subscriber lines, the second line card configured to cancel crosstalk affecting second symbols communicated across the second plurality of subscriber lines, thereby providing second crosstalk-compensated symbols, the second line card further configured to insert the second symbols into the vectoring stream and to transmit the second crosstalk-compensated symbols to the switching element, wherein the second line card is configured to receive the first symbols from the vectoring stream and to maintain a vectoring coefficient corresponding to a tone of one of the first symbols, wherein the second line card is configured to combine the one of the first symbols with the vectoring coefficient, thereby providing an estimate of crosstalk induced by the one of the first symbols and interfering with one of the second symbols, and wherein the second line card is configured to combine the estimate with the one of the second symbols, thereby cancelling the crosstalk induced by the one of the first symbols;
• and
• a third line card coupled to the switching element, the ring connection, and a third plurality of subscriber lines, the third line card configured to cancel crosstalk affecting third symbols communicated across the third plurality of subscriber lines, thereby providing third crosstalk-compensated symbols, the third line card further configured to insert the third symbols into the vectoring stream and to transmit the third crosstalk-compensated symbols to the switching element,
• wherein the line cards are configured to transmit the vectoring stream in a first direction around the ring connection and in a second direction around the ring connection opposite to the first direction thereby causing the vectoring stream to bypass the first line card when a failure occurs on the first line card.