Service chaining in a cloud environment using Software Defined Networking

1. A method for steering packet traffic comprising:

receiving a packet on an ingress port;

responsive to determining there is an entry corresponding to the packet stored in a microflow table, correlating the packet with a service chain identifier;

determining a next service type for the packet in accordance with the service chain identifier and the ingress port;

selecting an instance of the next service in accordance with the determined next service type and a load balancing algorithm distributing packet traffic between a plurality of instances of the next service; and

forwarding the packet to the selected instance of the next service.

2. The method of claim 1 , further comprising, responsive to determining that the received packet has an associated service chain tag, removing the service chain tag from the packet.

3. The method of claim 1 , further comprising storing the service chain identifier in metadata associated with the packet.

4. The method of claim 1 , wherein the instance of the next service is selected further in accordance with at least one parameter associated with the packet.

5. The method of claim 1 , wherein the instance of the next service is selected further in accordance with a non-packet parameter.

6. The method of claim 1 , further comprising setting a destination address of the packet in accordance with the selected instance of the next service.

7. The method of claim 1 , further comprising selecting an egress port in accordance with the selected instance of the next service.

8. The method of claim 7 , wherein, responsive to determining that the egress port is a transit port, attaching a service chain tag to the packet.

9. A method for steering packet traffic comprising:

receiving a packet on an ingress port;

responsive to determining there is no entry corresponding to the packet stored in a microflow table, creating a new entry in the microflow table;

correlating the packet with the new entry in the microflow table and a service chain identifier;

determining a next service type for the packet in accordance with the service chain identifier and the ingress port;

selecting an instance of the next service in accordance with the determined next service type; and

forwarding the packet to the selected instance of the next service.

10. The method of claim 9 , further comprising assigning a new service chain identifier to a traffic flow associated with the packet.

11. The method of claim 9 , wherein the instance of the next service is selected in accordance with a load balancing algorithm distributing packet traffic between a plurality of instances of the next service.

12. The method of claim 9 , wherein the instance of the next service is selected in accordance with at least one of a packet parameter or a non-packet parameter.

13. A switch comprising a communication interface, a processor, and a memory, the memory containing instructions executable by the processor whereby the switch is operative to:

receive a packet on an ingress port of the communication interface;

responsive to determining there is an entry corresponding to the packet stored in a microflow table, correlate the packet with a service chain identifier;

determine a next service type for the packet in accordance with the service chain identifier and the ingress port;

select an instance of the next service in accordance with the next service type and a load balancing algorithm distributing packet traffic between a plurality of instances of the next service; and

forward the packet to the selected instance of the next service by the communication interface.

14. The switch of claim 13 , further operative to, responsive to determining that the received packet has an associated service chain tag, remove the service chain tag from the packet.

15. The switch of claim 13 , wherein the instance of the next service is selected further in accordance with at least one parameter associated with the packet.

16. The switch of claim 13 , further operative to select an egress port of the communication interface in accordance with the selected instance of the next service.

17. The switch of claim 16 , further operative to attach a service chain tag to the packet in response to determining that the egress port is a transit port.

18. A switch comprising a communication interface, a processor, and a memory, the memory containing instructions executable by the processor whereby the switch is operative to:

receive a packet on an ingress port of the communication interface;

create a new entry in a microflow table in response to determining there is no entry corresponding to the packet stored in the microflow table;

correlate the packet with the new entry in the microflow table and a service chain identifier;

determine a next service type for the packet in accordance with the service chain identifier and the ingress port;

select an instance of the next service in accordance with the determined next service type; and

forward the packet to the selected instance of the next service.

19. The switch of claim 18 , wherein creating a new entry in the microflow table includes assigning a new service chain identifier to a traffic flow associated with the packet.

20. The switch of claim 18 , wherein the instance of the next service is selected in accordance with a load balancing algorithm distributing packet traffic between a plurality of instances of the next service.

21. The switch of claim 18 , wherein the instance of the next service is selected in accordance with a load balancing algorithm distributing packet traffic between a plurality of instances of the next service.

22. A forwarding element comprising:

an ingress port for receiving a packet;

a microflow table module for correlating the packet with a service chain;

a next service table module for determining a next service type for the packet in accordance with the service chain and the ingress port;

a load balancing table module for selecting an instance of the next service in accordance with the determined next service type and a load balancing algorithm distributing packet traffic between a plurality of instances of the next service; and

an egress port for forwarding the packet towards a destination address associated with the selected instance of the next service.