Propagating flow characteristics in service function chaining (SFC) headers

1. A method, comprising:

determining, by a service function classifier device, a classification of a packet using one or more packet classification rules;

selecting, by the device, a service function path based on the classification of the packet;

determining, by the device, one or more traffic flow characteristics based on the classification of the packet, wherein the one or more traffic flow characteristics are propagated across a plurality of Differentiated Services (DiffServ) domains;

generating, by the device, a service function chaining (SFC) header that identifies the selected service function path and the determined one or more traffic flow characteristics, wherein the SFC header is configured to cause a node along the service function path to forward the encapsulated packet based on the identified service function path and the determined one or more traffic flow characteristics; and

sending, by the device, the packet along the selected service function path as an encapsulated packet that includes the generated SFC header.

2. The method as in claim 1 , wherein the one or more traffic flow characteristics comprise one or more quality of service (QoS) parameters.

3. The method as in claim 2 , wherein the one or more QoS parameters identify one or more of: a bandwidth requirement, a delay requirement, a jitter requirement, or a packet loss requirement.

4. The method as in claim 3 , wherein the one or more traffic flow characteristics identify whether the one or more QoS parameters apply to upstream or downstream traffic.

5. The method as in claim 1 , wherein the SFC header comprises a Network Service Header (NSH)-based header, and wherein the one or more traffic flow characteristics are included in one or more context header fields of the NSH-based header.

6. The method as in claim 1 , wherein the packet is part of a multiplexed traffic flow.

7. An apparatus, comprising:

one or more network interfaces to communicate with a network;

a processor coupled to the network interfaces and configured to execute one or more processes; and

a memory configured to store a process executable by the processor, the process when executed operable to:

receive a packet, wherein the packet is encapsulated using a service function chaining (SFC) header;

identify a service function path and one or more traffic flow characteristics from the SFC header, wherein the one or more traffic flow characteristics are propagated across a plurality of Differentiated Services (DiffServ) domains;

determine a quality of service (QoS) requirement for the packet based on the one or more traffic flow characteristics; and

send the packet to a particular service function based on the QoS requirement for the packet.

8. The apparatus as in claim 7 , wherein the one or more traffic flow characteristics identify one or more of: a bandwidth requirement, a delay requirement, a jitter requirement, or a packet loss requirement.

9. The apparatus as in claim 8 , wherein the process when executed is further operable to:

determine whether the one or more traffic flow characteristics apply to the received packet, based on whether the received packet is an upstream packet or a downstream packet.

10. The apparatus as in claim 7 , wherein the SFC header comprises a Network Service Header (NSH)-based header, and wherein the one or more traffic flow characteristics are included in one or more context header fields of the NSH-based header.

11. The apparatus as in claim 10 , wherein the process when executed is further operable to:

send the packet with the NSH-based header to a device located in a different domain than that of the apparatus, wherein the NSH-based header is configured to cause the device in the different domain to forward the encapsulated packet based on the identified service function path and the determined one or more traffic flow characteristics.

12. An apparatus, comprising:

one or more network interfaces to communicate with a network;

a processor coupled to the network interfaces and configured to execute one or more processes; and

a memory configured to store a process executable by the processor, the process when executed operable to:

determine a classification of a packet using one or more packet classification rules;

select a service function path based on the classification of the packet;

determine one or more traffic flow characteristics based on the classification of the packet, wherein the one or more traffic flow characteristics are propagated across a plurality of Differentiated Services (DiffServ) domains;

generate a service function chaining (SFC) header that identifies the selected service function path and the determined one or more traffic flow characteristics, wherein the SFC header is configured to cause a device along the service function path to forward the encapsulated packet based on the identified service function path and the determined one or more traffic flow characteristics; and

send the packet along the selected service function path as an encapsulated packet that includes the generated SFC header.

13. The apparatus as in claim 12 , wherein the one or more traffic flow characteristics comprise one or more quality of service (QoS) parameters.

14. The apparatus as in claim 13 , wherein the one or more QoS parameters identify one or more of: a bandwidth requirement, a delay requirement, a jitter requirement, or a packet loss requirement.

15. The apparatus as in claim 14 , wherein the one or more traffic flow characteristics identify whether the one or more QoS parameters apply to upstream or downstream traffic.

16. The apparatus as in claim 12 , wherein the SFC header comprises a Network Service Header (NSH)-based header, and wherein the one or more traffic flow characteristics are included in one or more context header fields of the NSH-based header.

17. The apparatus as in claim 12 , wherein the packet is part of a multiplexed traffic flow.

18. The apparatus as in claim 12 , wherein the packet is a multimedia packet.