METHOD, APPARATUS, AND SYSTEM FOR LOAD BALANCING OF SERVICE CHAIN

• US 20170048148A1
• Filed: 10/27/2016
• Published: 02/16/2017
• Est. Priority Date: 04/28/2014
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: HUANG, Shibi, HUANG, Yong, TIAN, Yong, DUNBAR, Linda
• Granted Patent: US 10,673,760 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 41/508 based on type of value added network service under agreement
• CPC Class Codes: H04L 45/38 Flow based routing
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 47/31 by tagging of packets, e.g. using discard eligibility [DE] bits
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs

Abstract

A method, an apparatus, and a system are provided for load balancing of a service chain. The method includes: receiving, by a flow classifier, a service chain selection and control policy sent by a policy and charging rules function PCRF unit; hashing, by the flow classifier according to a hash quantity, a service flow corresponding to a service chain identifier, to obtain multiple subflows, and adding the service chain identifier and hashing factors to packets of the subflows, where different subflows correspond to different hashing factors; and sending, by the flow classifier, the packets of the subflows after the service chain identifier and the hashing factors are added, to a forwarding device.

Claims

1. A flow classifier, comprising a receiver, a processor, and a transmitter, wherein:

the receiver is configured to receive a service chain selection and control policy sent by a policy and charging rules function (PCRF) unit, and send the service chain selection and control policy to the processor, wherein the service chain selection and control policy comprises a service chain identifier and a correspondence between a service chain and a hash quantity, and the service chain selection and control policy is used to instruct the flow classifier to hash a service flow passing through the service chain, into subflows according to the hash quantity;

the processor is configured to hash, according to the hash quantity, the service flow corresponding to the service chain identifier, to obtain multiple subflows, add the service chain identifier and hashing factors to packets of the subflows, and send the packets of the subflows to the transmitter, wherein different subflows correspond to different hashing factors; and

the transmitter is configured to send the packets of the subflows after the service chain identifier and the hashing factors are added, to a forwarding device.

2. The flow classifier according to claim 1, wherein the processor is further configured to:

in a first time segment, add a same hashing factor to packets of a same session of a same user, so that the packets of the same session of the same user are allocated to a same subflow, and add the service chain identifier to the packets of the subflow.

3. The flow classifier according to claim 2, wherein the processor is further configured to:

in the first time segment, add the same hashing factor to upstream packets and downstream packets of the same session of the same user, so that the upstream packets and downstream packets of the same session of the same user are allocated to the same subflow, and add the service chain identifier and the hashing factor to the packets of the subflow.

4. The flow classifier according to claim 2, wherein the service chain selection and control policy further comprises a status flag, wherein the status flag is used to indicate a before-expansion state or an after-expansion state, wherein the expansion is used to indicate that a quantity of value-added service devices of a same type increases;

and

the processor is further configured to add the status flag indicating the before-expansion state, to a session that already exists before the expansion, add a hashing factor used by the existing session before the expansion, to packets of the existing session that are generated after the expansion, and add the status flag indicating the after-expansion state, to a session created after the expansion.

5. A controller, comprising a processor and a memory accessible to the processor, wherein the processor is configured to:

receive a logical service chain definition and a hash quantity, wherein the logical service chain definition comprises information about at least one type of value-added service device that a service chain passes through, the service chain comprises at least one forwarding device that a service flow passes through and value-added service devices that the service flow passes through, the service chain has a service chain identifier, the service chain corresponds to the hash quantity, the hash quantity is configured to indicate a quantity of subflows that the service flow passing through the service chain is hashed into, and different subflows correspond to different hashing factors;

determine, according to the hash quantity and a quantity of value-added service devices participating in a service, in value-added service devices of a same type, a subflow allocated to each value-added service device participating in the service, in the value-added service devices of the same type;

generate, according to the logical service chain definition and subflow allocation information, a first flow forwarding table for the at least one forwarding device that the service chain passes through, wherein the first flow forwarding table comprises first matching information and first operation information, wherein the first matching information comprises the service chain identifier and the hashing factors, and the first operation information is configured to instruct the at least one forwarding device to send, after receiving a first packet having the service chain identifier and the hashing factor, the first packet to a value-added service device to which a subflow comprising the first packet is allocated; and

send, to the at least one forwarding device that the service chain passes through, the first flow forwarding table generated for the at least one forwarding device.

6. The controller according to claim 5, wherein the processor is further configured to determine, according to the hash quantity, the quantity of the value-added service devices participating in the service, in the value-added service devices of the same type, and processing capabilities of the value-added service devices participating in the service, in the value-added service devices of the same type, the subflow allocated to each value-added service device participating in the service, in the value-added service devices of the same type.

7. The controller according to claim 5, wherein the processor is further configured to:

when a value-added service device in the value-added service devices of the same type quits the service, allocate a subflow that is originally allocated to the value-added service device that quits the service, to a remaining value-added service device in the value-added service devices of the same type; and

generate a second flow forwarding table according to subflow reallocation information, wherein the second flow forwarding table comprises second operation information, wherein the second operation information is configured to instruct the at least one forwarding device to send, after receiving the first packet having the service chain identifier and having a hashing factor of the subflow that is originally allocated to the value-added service device that quits the service, the first packet to the remaining value-added service device in the value-added service devices of the same type.

8. The controller according to claim 5, wherein the processor is further configured to:

receive a status flag, wherein the status flag is configured to indicate a before-expansion state or an after-expansion state, wherein the expansion is configured to indicate that the quantity of the value-added service devices of the same type increases;

re-determine, according to the status flag, the hash quantity, and the quantity of the value-added service devices participating in the service, in the value-added service devices of the same type, the subflow allocated to each value-added service device participating in the service, in the value-added service devices of the same type; and

generate, according to the logical service chain definition and subflow reallocation information, a third flow forwarding table for the at least one forwarding device that the service chain passes through, wherein the third flow forwarding table comprises third operation information, wherein the third operation information is configured to instruct the at least one forwarding device to send, after receiving the first packet having the service chain identifier and the hashing factor, the first packet to a value-added service device to which the subflow comprising the first packet is reallocated.

9. The controller according to claim 8, wherein the processor is further configured to determine, according to the status flag, the hash quantity, the quantity of the value-added service devices participating in the service, in the value-added service devices of the same type, and processing capabilities of the value-added service devices participating in the service, in the value-added service devices of the same type, the subflow allocated to each value-added service device participating in the service, in the value-added service devices of the same type.

10. A system for load balancing of a service chain, comprising a controller and a flow classifier, wherein:

the controller comprising a first receiver, a first determining circuitry, a first generating circuitry, and a first transmitter, wherein;

the first receiver is configured to receive a logical service chain definition and a hash quantity, send the hash quantity to the first determining circuitry, and send the logical service chain definition to the first generating circuitry, wherein the logical service chain definition comprises information about at least one type of value-added service device that a service chain passes through, the service chain comprises at least one second forwarding device that a service flow passes through and value-added service devices that the service flow passes through, the service chain has a service chain identifier, the service chain corresponds to the hash quantity, the hash quantity is used to indicate a quantity of subflows that the service flow passing through the service chain is hashed into, and different subflows correspond to different hashing factors;

the first determining circuitry is configured to determine, according to the hash quantity and a quantity of value-added service devices participating in a service, in value-added service devices of a same type, a subflow allocated to each value-added service device participating in the service, in the value-added service devices of the same type, and send subflow allocation information to the first generating circuitry;

the first generating circuitry is configured to generate, according to the logical service chain definition and subflow allocation information, a first flow forwarding table for each of the at least one second forwarding device that the service chain passes through, and send the first flow forwarding table to the first transmitter, wherein the first flow forwarding table comprises first matching information and first operation information, wherein the first matching information comprises the service chain identifier and the hashing factors, and the first operation information is used to instruct the at least one second forwarding device to send, after receiving a first packet having the service chain identifier and the hashing factor, the first packet to a value-added service device to which a subflow comprising the first packet is allocated; and

the first transmitter is configured to send, to each of the at least one second forwarding device that the service chain passes through, the first flow forwarding table generated for each of the at least one second forwarding device;

the flow classifier comprising a receiver, a processor, and a transmitter, wherein;

the receiver is configured to receive a service chain selection and control policy sent by a policy and charging rules function PCRF unit, and send the service chain selection and control policy to the processor, wherein the service chain selection and control policy comprises a service chain identifier and a correspondence between a service chain and a hash quantity, and the service chain selection and control policy is used to instruct the flow classifier to hash a service flow passing through the service chain, into subflows according to the hash quantity;

the processor is configured to hash, according to the hash quantity, the service flow corresponding to the service chain identifier, to obtain multiple subflows, add the service chain identifier and hashing factors to packets of the subflows, and send the packets of the subflows to the transmitter, wherein different subflows correspond to different hashing factors; and

the transmitter is configured to send the packets of the subflows after the service chain identifier and the hashing factors are added, to a third forwarding device.

11. The system of claim 10, further comprising a policy and charging rules function (PCRF) unit, at least one forwarding device, and multiple value-added service devices, wherein the at least one forwarding device is interconnected, the flow classifier is connected to the PCRF unit and the at least one forwarding device, and the at least one forwarding device is further connected to the controller and the value-added service devices, wherein:

the PCRF unit is configured to determine a service chain selection and control policy according to policy context information, a service chain selection policy, and a hash quantity, wherein the service chain selection policy comprises a correspondence between the policy context information and the service chain, the service chain selection and control policy comprises a service chain identifier and a correspondence between the service chain and the hash quantity, and the service chain selection and control policy is used to instruct the flow classifier to hash a service flow passing through the service chain, into subflows according to the hash quantity;

the third forwarding device is configured to;

when receiving a packet to which the service chain identifier and a hashing factor are added and which is sent by the flow classifier, match the packet according to the service chain identifier and hashing factors in first matching information in a first flow forwarding table sent by the controller, then perform an operation according to first operation information, and send a first packet having the service chain identifier and the hashing factor in the first matching information to a value-added service device to which a subflow comprising the first packet is allocated.