# US 10,454,827 B2 · Method and devices for controlling usage of multi-path TCP

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- Number: US 10,454,827 B2
- Document ID: US10454827B2
- Status: Granted
- Kind: B2
- Application number: 15/311,134
- Filed: 2014-05-15
- Published: 2017-03-23
- Granted: 2019-10-22
- Earliest claimed: 2014-05-15
- Assignees: Telefonaktiebolaget LM Ericsson (publ)
- Applicants: Telefonaktiebolaget Lm Ericsson (Publ)
- Inventors: Bo Hellander; Elinor Aminoff; Christofer Lindheimer; Martin Skarve; Jari Vikberg
- Web page: https://patentgrep.com/patent/US10454827B2

## CPC

- H04L 69/16: Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
- H04L 47/11: Identifying congestion
- H04L 69/14: Multichannel or multilink protocols
- H04W 24/08: Testing, {supervising or monitoring} using real traffic
- H04W 28/0205: {at the air interface (dynamic wireless traffic scheduling H04W72/12)}
- H04W 80/06: Transport layer protocols, e.g. TCP [Transport Control Protocol] over wireless {(transmission control protocol/Internet protocol [TCP/IP] or user datagram protocol [UDP] H04L69/16)}
- H04L 69/22: Parsing or analysis of headers
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A method performed by a network element in a communication network comprises inspecting traffic between a radio device and the communication network. The method also comprises, based on said inspecting, determining that the traffic is part of a TCP subflow of an MPTCP connection. The method also comprises, based on said inspecting, calculating a ratio of how much data is transmitted in the subflow in relation to the total amount of data transmitted in the MPTCP connection over a predetermined time period. The method also comprises observing that the calculated ratio is below a reference ratio. The method also comprises, based on said observing, performing an action for preventing congestion in the communication network.

## Claims

### Claim 1

A method performed by a network element in a communication network, the method comprising:
inspecting traffic between a radio device and the communication network; wherein said inspecting traffic comprises inspecting headers of data packets of the traffic; wherein said inspecting headers comprises inspecting data sequence number (DSN) and Subflow Sequence Numbers (SSN) of the data packets;
determining, based on said inspecting traffic, that the traffic is part of a Transmission Control Protocol (TCP) subflow of a multi-path TCP (MPTCP) connection;
calculating, based on said inspecting traffic, a ratio of how much data is transmitted in the subflow in relation to the total amount of data transmitted in the MPTCP connection over a predetermined time period;
observing that the calculated ratio is below a reference ratio, wherein the reference ratio is a corresponding calculated ratio of another radio access bearer (RAB), which is currently used with a Radio Access Network (RAN) to set a priority of the TOP subflow in comparison with said another RAB; and
performing, based on said observing, an action for preventing congestion in the communication network; the performing an action comprises preempting a radio access bearer, (RAB) of the radio device, wherein said preempting is performed by releasing lower priority radio access bearers or radio devices when related resources are needed for higher priority radio access bearers or radio devices.

### Claim 2 (depends on 1)

The method of claim 1, wherein the performing an action comprises rejecting resources to realize a radio access bearer (RAB) of the radio device for setting up the RAB with the communication network.

### Claim 3 (depends on 1)

The method of claim 1, wherein the performing an action comprises assigning a priority level to a radio access bearer (RAB) of the radio device.

### Claim 4 (depends on 1)

The method of claim 1, wherein the inspecting traffic comprises detection of MPTCP signalling indicative of a backup TCP subflow.

### Claim 5 (depends on 1)

The method of claim 1, further comprising:
based on said inspecting, determining that also an amount of non-MPTCP data traffic is comprised in the inspected traffic in the same RAB which comprises the MPTCP subflow, over the time period;
wherein the observing comprises observing that the amount of non-MPTCP data traffic is below a non-MPTCP threshold.

### Claim 6 (depends on 1)

The method of claim 1, wherein the network element is located in a radio access network (RAN) in the communication network, such as in a base station controller (BSC) of a Global System for Mobile Communications (GSM) communication network, in a radio network controller (RNC) of a Wideband Code Division Multiple Access (WCDMA) communication network, or in an evolved Node B (eNB) of a Long Term Evolution (LTE) communication network.

### Claim 7 (depends on 1)

A computer program product comprising computer-executable components for causing a network element in a communication network to perform the method of claim 1 when the computer-executable components are run on processor circuitry comprised in the network element.

### Claim 8

A network element in a communication network, the network element comprising:
processor circuitry; and
a storage unit storing instructions executable by said processor circuitry whereby said network element is operative to:
inspect traffic between a radio device and the communication network;
determine, based on said inspecting traffic, that the traffic is part of a Transmission Control Protocol (TCP) subflow of an MPTCP connection;
calculate, based on said inspecting traffic, a ratio of how much data is transmitted in the subflow in relation to the total amount of data transmitted in the MPTCP connection over a predetermined time period;
observe that the calculated ratio is below a reference ratio, wherein the reference ratio is a corresponding calculated ratio of another radio access bearer (RAB), which is currently used with a Radio Access Network (RAN) to set a priority of the TCP subflow in comparison with said another RAB; and
perform, based on said observing, an action for preventing congestion in the communication network; wherein said perform an action comprises preempting a radio access bearer of the radio device, and wherein said preempting is performed by releasing lower priority radio access bearers or radio devices when related resources are needed for higher priority radio access bearers or radio devices.

### Claim 9 (depends on 8)

A radio access network (RAN) node for a communication network, comprising the network element of claim 8.

### Claim 10

A non-transitory computer-readable medium comprising computer program code which is able to, when run on processor circuitry of a network element, cause the network element to:
inspect traffic between a radio device and the communication network;
determine, based on said inspecting traffic, that the traffic is part of a Transmission Control Protocol (TCP) subflow of an MPTCP connection;
calculate, based on said inspecting traffic, a ratio of how much data is transmitted in the subflow in relation to the total amount of data transmitted in the MPTCP connection over a predetermined time period;
observe that the calculated ratio is below a reference ratio; wherein the reference ratio is a corresponding calculated ratio of another radio access bearer (RAB), which is currently used with a Radio Access Network (RAN) to set a priority of the TCP subflow in comparison with said another RAB; and
perform, based on said observing, an action for preventing congestion in the communication network; wherein said perform an action comprises preempting a radio access bearer, (RAB) of the radio device, and wherein said preempting is performed by releasing lower priority radio access bearers or radio devices when related resources are needed for higher priority radio access bearers or radio devices.