Setting and changing queue sizes in line cards

A method comprising:

• measuring, over a time interval, an average number of packet headers in a memory space, allocated to a queue, into which headers of packets that arrive at a line card are temporarily stored;
• measuring, over the time interval, an average length of the packets;
• allocating additional memory from either free memory or re-allocating memory spaces allocated to other queues in the line card when the line card determines that the memory space allocated to the queue is smaller than a desired size for buffering bursts of packets, based on the measured number of packet headers;
• increasing a size of the memory space allocated to the queue to the desired size by using the allocated additional memory;
• receiving a packet at the line card;
• storing a header of the packet in the queue and the packet in a packet buffer;
• modifying an initial size of the packet buffer based on the average length of packets and a maximum number of packet headers that the queues in the line card can store;
• and
• forwarding the header from the allocated memory space and the packet from packet buffer in the line card to a second line card.

A method comprising:

• setting an initial maximum capacity of a storage space, allocated to a queue, of a plurality of queues, into which header cells associated with packets that arrive at a line card are temporarily stored;
• exchanging, with routers, messages that include information for determining a desired maximum capacity of the storage space allocated to the queue;
• allocating memory from other queues in the line card to the queue when the line card determines that the set maximum capacity of the storage space allocated to the queue is smaller than the desired maximum capacity for buffering bursts of packets, when a number of the routers indicate that the desired maximum capacity exceeds a threshold;
• receiving a packet at the line card;
• set an initial maximum size of a packet buffer provided for the queuing of the packet;
• increase the initial maximum size of the packet buffer based on an average size of the packets that arrive at the line card, and a maximum number of header cells that the space allocations for each of the queues can store;
• storing a header cell associated with the packet in the queue;
• and
• forwarding the header cell to a second line card.