# US 2021/0243124 A1 · Service function chaining congestion feedback > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243124 A1 - Document ID: US20210243124A1 - Status: Published application - Kind: A1 - Application number: 17/175,964 - Filed: 2021-02-15 - Published: 2021-08-05 - Earliest claimed: 2018-02-23 - Assignees: Futurewei Technologies, Inc. - Applicants: Futurewei Technologies, Inc. - Inventors: Donald E. Eastlake, III; Andrew G. Malis - Web page: https://patentgrep.com/patent/US20210243124A1 ## CPC - H04L 47/115: {using a dedicated packet} - H04L 43/062: related to network traffic - H04L 43/091: Measuring contribution of individual network components to actual service level - H04L 47/22: Traffic shaping - H04L 47/2483: involving identification of individual flows - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method of reporting congestion in an upstream direction in a service chain function architecture. The method includes receiving, by the downstream device, a packet indicating congestion within a service function chaining architecture; generating, by the downstream device, a congestion report message in response to receiving the packet, wherein the congestion report message comprises a field indicating an existence of congestion within the service function chaining architecture and a service path identifier indicating a location of the congestion within the service function chaining architecture; and transmitting, by the downstream device, the congestion report message to an upstream device to permit the upstream device to address the congestion. ## Claims ### Claim 1 A method of reporting congestion to an upstream device implemented by a downstream device, comprising: receiving, by the downstream device, a packet indicating congestion on a path within a service function chaining architecture; generating, by the downstream device, a congestion report message in response to receiving the packet, wherein the congestion report message comprises a field indicating an existence of congestion within the service function chaining architecture and a service path identifier indicating a flow of the congestion within the service function chaining architecture; and transmitting, by the downstream device, the congestion report message to an upstream device to permit the upstream device to alleviate the congestion; wherein the upstream device includes a classifier configured to meter or direct the flow of packets in response to receiving the congestion report message from the downstream device. ### Claim 2 (depends on 1) The method of claim 1, wherein the packet comprises a plurality of unused bits fields, and wherein at least two of the unused bit fields contain a value to indicate the congestion within the service function chaining architecture. ### Claim 3 (depends on 2) The method of claim 2, wherein the value is represented by one or more binary numbers. ### Claim 4 (depends on 1) The method of claim 1, wherein the downstream device is an exit node in the service function chaining architecture. ### Claim 5 (depends on 1) The method of claim 1, wherein the downstream device is a service function forwarder (SFF) in the service function chaining architecture. ### Claim 6 (depends on 1) The method of claim 1, wherein the packet comprises a network service header (NSH) and the congestion report message includes a modified version of the NSH. ### Claim 7 (depends on 6) The method of claim 6, wherein the modified version of the NSH identifies a meta data (MD) type, and wherein meta data corresponding to the MD type is structured as one or more fields or type length values (TLVs). ### Claim 8 A method of reporting congestion to an upstream device implemented by a downstream device in a service function chaining architecture, comprising: receiving, by the downstream device, a packet containing two congestion bits that have been set in a network service header (NSH); generating, by the downstream device, a congestion report message in response to receiving the packet, wherein the congestion report message indicates an existence of congestion on a path within the service function chaining architecture and a flow of the congestion within the service function chaining architecture; and transmitting, by the downstream device, the congestion report message to an upstream device within the service function chaining architecture, wherein the congestion report message instructs the upstream device address the congestion; wherein the upstream device includes a classifier configured to meter or direct the flow of packets in response to receiving the congestion report message from the downstream device. ### Claim 9 (depends on 8) The method of claim 8, wherein the existence of the congestion is indicated by manipulating at least one field in the NSH of the packet and including the at least one field in the congestion report message when generated. ### Claim 10 (depends on 8) The method of claim 8, wherein the location of the congestion is indicated by manipulating a service path identifier in the NSH of the packet and including the service path identifier as manipulated in the congestion report message when generated. ### Claim 11 (depends on 8) The method of claim 8, wherein the downstream device is an exit node in the service function chaining architecture. ### Claim 12 (depends on 8) The method of claim 8, wherein the downstream device is a service function forwarder (SFF) in the service function chaining architecture. ### Claim 13 An upstream device in a service function chaining architecture, comprising: a memory comprising instructions; a processor in communication with the memory, wherein the processor executes the instructions to: transmit a packet to a downstream device; receive a congestion report message from the downstream device in response to transmission of the packet, wherein the congestion report message comprises a field indicating an existence of congestion within the service function chaining architecture and a service path identifier indicating a flow of the congestion within the service function chaining architecture; and alleviate the congestion identified in the congestion report message; wherein the processor executes the instructions to meter or direct the flow of packets in response to receiving the congestion report message from the downstream device. ### Claim 14 (depends on 13) The upstream device of claim 13, wherein the packet comprises a plurality of unused bits fields, and wherein at least two of the unused bit fields contain a value to indicate the congestion within the service function chaining architecture. ### Claim 15 (depends on 14) The upstream device of claim 14, wherein the value is represented by one or more binary numbers. ### Claim 16 (depends on 13) The downstream device of claim 13, wherein the downstream device is an exit node in the service function chaining architecture. ### Claim 17 (depends on 13) The downstream device of claim 13, wherein the downstream device is a service function forwarder (SFF) in the service function chaining architecture. ### Claim 18 (depends on 13) The downstream device of claim 13, wherein the packet comprises a network service header (NSH) and the congestion report message includes a modified version of the NSH.