Patent ID: 8036128

Claim:
A method of communicating an in-band backpressure signaling message (IBSM) over a first serial encoded link, the method comprising: receiving, by a receiver of packets over a first serial encoded link, at least one protocol data unit (PDU) from a first data transmitter; forming, by the receiver of packets over the first serial encoded link, a backpressure message PDU when triggered by a contextual control scheme, the step comprising: forming a start of backpressure delineator (SBP), wherein the SBP includes a control character and a data character representing a backpressure message packet (BP) length between 2 and 128 bytes; appending, to the SBP, the BP that supports backpressure signaling operations, comprising a plurality of 2-byte data blocks, each 2-byte data block including a first plurality of bits corresponding to the contextual control scheme and a second plurality of bits comprising a BP context for the contextual control scheme, wherein the BP context is one of a plurality of contexts supported by the contextual control scheme; transmitting, by the receiver of packets, the backpressure message PDU on the first serial encoded link to the first data transmitter, wherein the first data transmitter uses a first BP context of a first 2-byte data block to modify the first serial encoded link; and transmitting, by the first data transmitter, the backpressure message to a second data transmitter over a second serial encoded link, wherein the second data transmitter sends at least one PDU to the first data transmitter, the first serial encoded link includes fewer contexts than the plurality of BP contexts fully encoded in the backpressure message, and the second data transmitter uses at least one BP context of the plurality of BP contexts to modify the second serial encoded link.