Conditional bandwidth subscriptions for multiprotocol label switching (MPLS) label switched paths (LSPs)

A method for allocating excess bandwidth in a data communication network on a subscription basis, the method comprising:

• allocating a first subscribed bandwidth and a second subscribed bandwidth for a flow;
• receiving a first packet in the flow below the first subscribed bandwidth for the flow;
• receiving a second packet in the flow above the first subscribed bandwidth and below the second subscribed bandwidth for the flow;
• if congestion is detected, storing the first packet and discarding the second packet;
• and
• if no congestion is detected, storing the first packet and the second packet.

A switching node comprising:

• an input port;
• an output port;
• and
• a buffer coupled to the input port and the output port, the buffer including a first area reserved for storing packets during periods of congestion and a second area reserved for storing packets during periods of no congestion.

A method for controlling network traffic in a data communication network, the method comprising:

• signaling a traffic flow including a first subscribed bandwidth and second subscribed bandwidth through a data communication network;
• receiving a packet in the traffic flow;
• identifying the packet as a first profile packet if the packet conforms to the first subscribed bandwidth;
• identifying the packet as a second profile packet if the packet does not conform to the first subscribed bandwidth and conforms to the second subscribed bandwidth;
• and
• processing the packet in accordance with the result of profile identification.