LINK SELECTION FOR COMMUNICATION WITH A SERVICE FUNCTION CLUSTER

• US 20180026887A1
• Filed: 07/21/2016
• Published: 01/25/2018
• Est. Priority Date: 07/21/2016
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Nainar, Nagendra Kumar, Asati, Rajiv, Pignataro, Carlos M.
• Granted Patent: US 10,218,616 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• CPC Class Codes: H04L 41/0866 Checking the configuration
• CPC Class Codes: H04L 41/0895 Configuration of virtualised networks or elements, e.g. virtualised network function or OpenFlow elements
• CPC Class Codes: H04L 41/22 comprising specially adapted graphical user interfaces [GUI]
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 45/0377 for service chaining
• CPC Class Codes: H04L 45/20 Hop count for routing purposes, e.g. TTL
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]
• CPC Class Codes: H04L 45/74 Address processing for routing

Abstract

Systems, methods, and computer-readable media for improving the reliability of service function (SF) application in a service function chain (SFC) are provided. In some aspects, the subject technology facilitates automatic service function type validation by a service function forwarder (SFF), for example, by using a probe configured query a function type of a SF module associated with the validating SFF.

Claims

1. A method for validating a service function type on a service function (SF) module, the method comprising:

initiating a probe, at a service function forwarder (SFF), wherein the probe is configured to query a function type of a corresponding SF module;

receiving a reply from the corresponding SF module in response to the probe;

validating, at the SFF, the function type of the corresponding SF module based on the reply; and

determining, at the SFF, whether to permit packet forwarding, based on the function type of the corresponding SF module.

2. The method of claim 1, wherein initiating the probe further comprises:

detecting, at the SFF, a change in service function instantiation at the corresponding SF module; and

automatically initiating the probe in response to the change in service function instantiation.

3. The method of claim 1, wherein initiating the probe further comprises:

detecting, at the SFF, a change relative to the SFF; and

automatically initiating the probe in response to the change relative to the SFF.

4. The method of claim 1, wherein initiating the probe further comprises:

generating a request for the corresponding SF module;

setting a service path identifier (SPI) of the request to a service index limit (SIL) value; and

forwarding the request to a forwarding address associated with the corresponding SF module.

5. The method of claim 1, wherein receiving the reply from the corresponding SF module further comprises:

determining if the reply comprises correct SPI and SIL values; and

reading the function type from the reply.

6. The method of claim 1, wherein validating the function type further comprises:

comparing the function type with a forwarding database to determine if the SF module is implementing an expected service function type.

7. The method of claim 1, wherein the probe comprises a modified service function chain (SF) traceroute configured for a single-hop transmission to the corresponding SF module.

8. A service function type validation system comprising:

at least one processor; and

a memory device storing instructions that, when executed by the at least one processor, cause the validation system to;

initiate a probe, at a service function forwarder (SFF), wherein the probe is configured to query a function type of a corresponding SF module;

receive a reply from the corresponding SF module in response to the probe;

validate, at the SFF, the function type of the corresponding SF module based on the reply; and

determine, at the SFF, whether to permit packet forwarding, based on the function type of the corresponding SF module.

9. The service function type validation system of claim 8, wherein initiating the probe further comprises:

detecting, at the SFF, a change in service function instantiation at the corresponding SF module; and

automatically initiating the probe in response to the change in service function instantiation.

10. The service function type validation system of claim 8, wherein initiating the probe further comprises:

detecting, at the SFF, a change relative to the SFF; and

automatically initiating the probe in response to the change relative to the SFF.

11. The service function type validation system of claim 8, wherein initiating the probe comprises:

generating a service function chain request for the corresponding SF module;

setting a service path identifier (SPI) of the request to a service index limit (SIL) value; and

forwarding the request to an address associated with the corresponding SF module.

12. The service function type validation system of claim 8, wherein receiving the reply from the corresponding SF module further comprises:

determining if the reply comprises correct SPI and SIL values; and

reading the function type from the reply.

13. The service function type validation system of claim 8, wherein validating the function type further comprises:

comparing the function type with a forwarding database to determine if the SF module is implementing an expected service function type.

14. The service function type validation system of claim 8, wherein the probe comprises a modified service function chain (SF) traceroute configured for a single-hop transmission to the corresponding SF module.

15. A non-transitory computer-readable storage medium comprising instructions stored therein, which when executed by one or more processors, cause the processors to perform operations comprising:

initiating a probe, at a service function forwarder (SFF), wherein the probe is configured to query a function type of a corresponding SF module;

receiving a reply from the corresponding SF module in response to the probe;

validating, at the SFF, the function type of the corresponding SF module based on the reply; and

determining, at the SFF, whether to permit packet forwarding, based on the function type of the corresponding SF module.

16. The non-transitory computer-readable storage medium of claim 15, wherein initiating the probe further comprises:

detecting, at the SFF, a change in service function instantiation at the corresponding SF module; and

automatically initiating the probe in response to the change in service function instantiation.

17. The non-transitory computer-readable storage medium of claim 15, wherein initiating the probe further comprises:

detecting, at the SFF, a change relative to the SFF; and

automatically initiating the probe in response to the change relative to the SFF.

18. The non-transitory computer-readable storage medium of claim 15, wherein initiating the probe comprises:

generating a request for the corresponding SF module;

setting a service function index of the request to a service index limit (SIL) value; and

forwarding the request to an address associated with the corresponding SF module.

19. The non-transitory computer-readable storage medium of claim 15, wherein receiving the reply from the corresponding SF module further comprises:

determining if the reply comprises correct SPI and SIL values; and

reading the function type from the reply.

20. The non-transitory computer-readable storage medium of claim 15, wherein validating the function type further comprises:

comparing the function type with a forwarding database to determine if the SF module is implementing an expected service function type.