METHOD AND APPARATUS FOR NETWORK FUNCTION CHAINING

1 . A method performed by a host device for directing a message through a network function, the method comprising:

receiving, at the host device, a first received message including a first identification of a first network function;

removing the first identification of the first network function from the first received message to create a first modified message; and

transmitting the first modified message to a first network function device for performance of the first network function with respect to the first modified message.

2 . The method of claim 1 , wherein the first received message additionally includes a second identification of a second network function, the method further comprising:

receiving, at the host device and based on transmitting the first modified message, a second received message including the second identification of the second network function;

removing the second identification of the second network function from the second received message to create a second modified message; and

transmitting the second modified message to a second network function device for performance of the second network function with respect to the second modified message.

3 . The method of claim 1 , wherein the first network function device is a virtualized device supported by the host device.

4 . The method of claim 1 , wherein:

the first received message includes a bitmap including a plurality of bit positions respectively corresponding to a plurality of network functions, and

the first indication of a first network function comprises a bit within the bitmap at a bit position corresponding to the first network function.

5 . The method of claim 1 , wherein the first identification of the first network function is at least partially represented in a destination address field of the first received message and removing the first identification of the first network function comprises modifying the value of the destination address field.

6 . The method of claim 5 , wherein the first received message is received from an external router, the method further comprising, before receiving the first received message:

receiving, at the host device from the external router, an address resolution request specifying a first address; and

transmitting, by the host device to the external router, an address resolution response specifying a second address as being associated with the first address, wherein the second address includes the first identification of the first network function.

7 . The method of claim 5 , wherein the host device supports a plurality of slots via which a plurality of devices are reachable, wherein a first slot of the plurality of slots supports the first network function device, and the step of removing the first identification of the first network function from the first received message to create a first modified message comprises, prior to transmitting the first modified message to the first slot:

setting the destination address field of the first modified message equal to an address of a second slot of the plurality of slots other than the first slot.

8 . A host device for directing a message through a network function, the host device comprising:

a network interface;

a memory storing a switch configuration; and

a processor in communication with the network interface and memory, the processor being configured to:

support a plurality of virtualized devices assigned to a respective plurality of slots, and

implement a virtualized switch, wherein the switch is configured to:

receive, via the network interface, a first received message including a first identification of a first slot of the plurality of slots,

remove, based on the switch configuration, the first identification of the first slot from the first received message to create a first modified message, and

transmit the first modified message to a first virtualized device supported by the first slot.

9 . The host device of claim 8 , wherein the first received message additionally includes a second identification of a second slot of the plurality of slots, the virtualized switch being further configured to:

receive, from the first slot and based on transmitting the first modified message, a second received message including the second identification of the second slot;

remove, based on the switch configuration, the second identification of the second slot from the second received message to create a second modified message; and

transmit the second modified message to a second virtualized device supported by the second slot.

10 . The host device of claim 8 , wherein:

the first received message includes a bitmap including a plurality of bit positions respectively corresponding to the plurality of slots, and

the first indication of a first slot comprises a bit within the bitmap at a bit position corresponding to the first slot.

11 . The host device of claim 8 , wherein the first identification of the first slot is at least partially represented in a destination address field of the first received message and, in removing the first identification of the first slot, the virtualized switch is configured to modify the value of the destination address field.

12 . The host device of claim 11 , wherein the first received message is received from an external router and the switch is further configured to, prior to receiving the first received message:

receive, via the network interface from the external router, an address resolution request specifying a first address; and

transmit, by the host device to the external router and based on the switch configuration, an address resolution response specifying a second address as being associated with the first address, wherein the second address includes the first identification of the first slot.

13 . The host device of claim 11 , wherein, in removing the first identification of the first slot from the first received message, the virtualized switch is configured to, prior to transmitting the first modified message to the first slot:

setting the destination address field of the first modified message equal to an address of a second slot of the plurality of slots other than the first slot.

14 . A non-transitory machine-readable storage medium encoded with instructions for execution by a host device for directing a message through a network function, the non-transitory machine-readable storage medium comprising:

instructions for receiving, at the host device, a first received message including a first identification of a first network function;

instructions for removing the first identification of the first network function from the first received message to create a first modified message; and

instructions for transmitting the first modified message to a first network function device for performance of the first network function with respect to the first modified message.

15 . The non-transitory machine-readable storage medium of claim 14 , wherein the first received message additionally includes a second identification of a second network function, the non-transitory machine-readable storage medium further comprising:

instructions for receiving, at the host device and based on transmitting the first modified message, a second received message including the second identification of the second network function;

instructions for removing the second identification of the second network function from the second received message to create a second modified message; and

instructions for transmitting the second modified message to a second network function device for performance of the second network function with respect to the second modified message.

16 . The non-transitory machine-readable storage medium of claim 14 , wherein the first network function device is a virtualized device supported by the host device.

17 . The non-transitory machine-readable storage medium of claim 14 , wherein:

the first received message includes a bitmap including a plurality of bit positions respectively corresponding to a plurality of network functions, and

the first indication of a first network function comprises a bit within the bitmap at a bit position corresponding to the first network function.

18 . The non-transitory machine-readable storage medium of claim 14 , wherein the first identification of the first network function is at least partially represented in a destination address field of the first received message and the instructions for removing the first identification of the first network function comprise instructions for modifying the value of the destination address field.

19 . The non-transitory machine-readable storage medium of claim 18 , wherein the first received message is received from an external router, the non-transitory machine-readable storage medium further comprising, before receiving the first received message:

instructions for receiving, at the host device from the external router, an address resolution request specifying a first address; and

instructions for transmitting, by the host device to the external router, an address resolution response specifying a second address as being associated with the first address, wherein the second address includes the first identification of the first network function.

20 . The non-transitory machine-readable storage medium of claim 18 , wherein the host device supports a plurality of slots via which a plurality of devices are reachable, wherein a first slot of the plurality of slots supports the first network function device, and the instructions for removing the first identification of the first network function from the first received message to create a first modified message comprise instructions for, prior to transmitting the first modified message to the first slot:

setting the destination address field of the first modified message equal to an address of a second slot of the plurality of slots other than the first slot.