Methods and apparatus for flow control associated with multi-staged queues

A processor-readable medium storing code representing instructions to cause a processor to perform a process, the code comprising code to:

• include an identifier of a transmit queue within a data packet received at the transmit queue, the transmit queue being disposed on a transmit side of a physical link;
• send the data packet to a receive queue via a transmission path that includes the transmit queue, the physical link, the receive queue, and a pair of queues associated with a flow control priority, the pair of queues being disposed within the transmission path between the receive queue and the transmit queue;
• and
• receive from a receive side of the physical link a flow control signal defined in response to the portion of the data packet being received at the receive queue, the flow control signal including the identifier of the transmit queue.

A method, comprising:

• receiving a first request to suspend transmission of a first data queued at a first stage of queues, the request associated with the first data being defined based on an availability of a first receive queue included in the first stage of queues, the first data being queued for transmission via a transmission path including a physical link and a portion of a second stage of queues disposed within the transmission path between the physical link and the first stage of queues;
• receiving a second request to suspend transmission of a second data queued at the first stage of queues, the request associated with the second data being defined based an availability of a second receive queue included in the first stage of queues, the second data being queued for transmission via the transmission path;
• and
• defining a flow control signal based on the first request and based on the second request.