An apparatus comprising: a source control module configured to define a first flow control signal based on a data flow associated with a first flow control loop, the first flow control loop including a physical link, a first stage of queues comprising at least one first stage transmit queue and at least one first stage receive queue, and a second stage of queues comprising at least one second stage transmit queue and at least one second stage receive queue, wherein the at least one second stage transmit queue is disposed within a transmission path between the physical link and the at least one first stage transmit queue and the at least one second stage receive queue is disposed within a transmission path between the physical link and the at least one first stage receive queue, the first flow control signal including a rate value for the at least one transmit queue associated with the first flow control loop and a suspension time value for the at least one transmit queue associated with the first flow control loop, wherein the source control module is operable to modify transmission from the at least one first stage transmit queue based on the first flow control signal; and wherein the source control module is further configured to define a second flow control signal based on a data flow within a second flow control loop, the second flow control loop including the second stage of queues and the physical link, the second flow control loop excluding the first stage of queues, wherein the source control module is operable to modify transmission from the at least one second stage transmit queue based on the second flow control signal. a source control module configured to define a first flow control signal based on a data flow associated with a first flow control loop, the first flow control loop including a physical link, a first stage of queues comprising at least one first stage transmit queue and at least one first stage receive queue, and a second stage of queues comprising at least one second stage transmit queue and at least one second stage receive queue, wherein the at least one second stage transmit queue is disposed within a transmission path between the physical link and the at least one first stage transmit queue and the at least one second stage receive queue is disposed within a transmission path between the physical link and the at least one first stage receive queue, the first flow control signal including a rate value for the at least one transmit queue associated with the first flow control loop and a suspension time value for the at least one transmit queue associated with the first flow control loop, wherein the source control module is operable to modify transmission from the at least one first stage transmit queue based on the first flow control signal; and wherein the source control module is further configured to define a second flow control signal based on a data flow within a second flow control loop, the second flow control loop including the second stage of queues and the physical link, the second flow control loop excluding the first stage of queues, wherein the source control module is operable to modify transmission from the at least one second stage transmit queue based on the second flow control signal.