Transport Protocols

UDP

Service Code

Service Name

wlcp

Desired Port Number

Description

Wireless LAN Control plane Protocol (WLCP) is a 3GPP control protocol used by the User Equipment (UE) for access to the Evolved Packet Core via trusted Wireless Local Area Network. It enables the management of the Packet Data Network (PDN) connections between the User Equipment (UE) and the Trusted WLAN Access Gateway (TWAG).

Wireless LAN Control plane Protocol (WLCP) uses UDP as a transport protocol.

Reference

3GPP TS 24.244

Defined TXT keys

N/A

If broadcast/multicast is used, how and what for?

Neither broadcast, nor multicast are used.

If UDP is requested, please explain how traffic is limited, and whether the protocol reacts to congestion.

At maximum a few WLCP messages per seconds are expected in communication between a given User Equipment (UE) and a given Trusted WLAN Access Gateway (TWAG).

Wireless LAN Control plane Protocol does not support any reaction to congestion.

If UDP is requested, please indicate whether the service is solely for the discovery of hosts supporting this protocol.

Wireless LAN Control plane Protocol is not used solely for discovery of hosts supporting this protocol.

Please explain how your protocol supports versioning.

Wireless LAN Control plane Protocol does not support versioning.

If your request is for more than one transport, please explain in detail how the protocol differs over each transport.

N/A

Please describe how your protocol supports security. Note that presently there is no IETF consensus on when it is appropriate to use a second port for an insecure version of a protocol.

Wireless LAN Control plane Protocol does not support security. It relies on the security mechanisms of the lower layers, including EAP-AKA’ authentication and IEEE 802.1x encryption.

Please explain why a unique port assignment is necessary as opposed to a port in range (49152-65535) or existing port.

An assigned User Port would make network management easier. It is possible that packets containing WLCP messages need to traverse several firewalls of the network operator during the signalling exchange between the User Equipment (UE) and the Trusted WLAN Access Gateway (TWAG). The firewalls of the network operator are configured to discard packets other than those containing the WLCP messages and other than those authorized by the WLCP messages. If a dynamic ephemeral port is used for WLCP messages, the firewall configuration needs to be updated whenever a new port starts being used for WLCP messages in the Trusted WLAN Access Gateway (TWAG).

An assigned User Port would make roaming agreements between network operators easier. If a dynamic port is used, each operator will need to provide the port number used by its TWAG to other operators, then the home operator needs to configure in its AAA sever the list of port numbers (in addition to the IP addresses) of the TWAGs of its roaming partners. If dynamic port is used, the port number can change frequently (while the IP address of the TWAG does not change frequently). Each time the port number changes, the roaming agreement documents needs to be updated. If dynamic port is used, the procedure to update the port numbers on the AAA server can cause a short interruption of the service.

As a general principle, 3GPP protocols use assigned User Ports, e.g. GTP-C uses UDP port number 2123, GTP-U uses UDP port number 2152, S1AP uses SCTP port number 36412, X2AP uses SCTP port number 36422. IKEv2 is an example of an IETF protocol between the terminal and a gateway that uses a well-known port number.

An assigned UDP port number would simplify the UE implementation. The UDP port number management between the application processor (AP) and the cellular modem would be simplified if the UDP port for WLCP could be set as a well-known port number. Specifically, there would be a need for an additional API between the WLCP client in the AP and the modem to identify the WLCP packets if dynamic ports are used.

Please explain the state of development of your protocol.

Protocol Standard definition. No implementation exists yet.

If SCTP is requested, is there an existing TCP and/or UDP service name or port number assignment? If yes, provide the existing service name and port number.

N/A

What specific SCTP capability is used by the application such that a user who has the choice of both TCP (and/or UDP) and SCTP ports for this application would choose SCTP? See RFC 4960 section 7.1.

N/A

Please provide any other information that would be helpful in understanding how this protocol differs from existing assigned services

This protocol is between the UE (i.e. mobile device) and the Trusted WLAN Gateway. The UDP ports previously assigned to 3GPP were for protocols between network elements.

Date

TSG #

TSG Doc.

CR

Rev

Subject/Comment

Old

New

2013-10

Draft skeleton provided

0.0.0

2013-10

CT1#84bis

Includes the following contribution agreed by CT1 at CT1#84bis:

C1-134145

0.0.0

0.1.0

2013-11

CT1#85

Includes the following contributions agreed by CT1 at CT#85: C1-134919, C1-134924, C1-135207.

0.1.0

0.2.0

2014-01

CT1#86

Includes the following contributions agreed by CT1 at CT#86: C1-140385, C1-140386, C1-130388, C1-140705.

0.2.0

0.3.0

2014-02

CT-63

CP-140112

Version 1.0.0 created for presentation to plenary for information

0.3.0

1.0.0

2014-04

CT1#86bis

Includes the following contribution agreed by CT1 at CT1#86bis:

C1-140813, C1-141260, C1-141262, C1-141265, C1-141266, C1-141267, C1-141309, C1-141580.

1.0.0

1.1.0

2014-05

CT1#87

Includes the following contribution agreed by CT1 at CT1#87:

C1-142127, C1-142128, C1-142129, C1-142519.

1.1.0

1.2.0

2014-07

CT1#88

Includes the following contribution agreed by CT1 at CT1#88:

C1-142739, C1-143004, C1-143006, C1-143044, C1-143320, C1-143369.

1.2.0

1.3.0

2014-09

CT-65

CP-140631

Version 2.0.0 created for presentation to plenary for approval

1.3.0

2.0.0

2014-09

CT-65

CP-140718

Plenary tdoc revised to include missing cover sheet

1.3.0

2.0.0

2014-09

Post CT-65

Version 12.0.0 created after approval at CT-65

2.0.0

12.0.0

2014-12

CT-66

CP-140840

0001

1

WLCP security

12.0.0

12.1.0

2014-12

CT-66

CP-140840

0003

1

Correct the reference on IPv6 network prefix allocation

12.0.0

12.1.0

2014-12

CT-66

CP-140840

0004

Correct the timer name

12.0.0

12.1.0

2014-12

CT-66

CP-140840

0005

Tx value IE

12.0.0

12.1.0

2014-12

CT-66

CP-140840

0006

2

Update to reference IEEE 802

12.0.0

12.1.0

2014-12

CT-66

CP-140840

0007

1

Procedure transaction identity

12.0.0

12.1.0

2014-12

CT-66

CP-140840

0008

1

Corrections and editorials to WLCP

12.0.0

12.1.0

2015-03

CT-67

CP-150065

0009

1

UDP port number assigned by IANA for WLCP

12.1.0

12.2.0

2015-06

CT-68

CP-150305

0010

1

Timer Tw1

12.2.0

12.3.0

2015-06

CT-68

CP-150305

0011

4

Reference to EAP authentication and authorization procedure

12.2.0

12.3.0

2015-09

CT-69

CP-150522

0015

1

WLCP PDN connectivity modification procedure for P-CSCF restoration

12.3.0

13.0.0

2015-09

CT-69

CP-150519

0016

1

Switch-on and switch-off terms in the context of WLCP for trusted WLAN access to EPC

12.3.0

13.0.0

2015-09

CT-69

CP-150526

0017

1

Routing rule and default access delivery during PDN connectivity establishment procedure

12.3.0

13.0.0

2015-09

CT-69

CP-150526

0018

1

IP flow mobility via WLCP PDN modification procedure

12.3.0

13.0.0

2015-12

CT-70

CP-150701

0019

Cleanup of TWAG-initiatd PDN connectivity modification procedure

13.0.0

13.1.0

2015-12

CT-70

CP-150710

0020

Correction of IP address handling during handover to TWAN

13.0.0

13.1.0

2015-12

CT-70

CP-150706

0021

Correction for the UE-initiated PDN connectivity modification procedure

13.0.0

13.1.0

2015-12

CT-70

CP-150696

0022

1

UE backoff Handling for trusted WLAN access to EPC using WLCP

13.0.0

13.1.0

2015-12

CT-70

CP-150706

0024

NBIFOM container correction

13.0.0

13.1.0

2015-12

CT-70

CP-150706

0025

1

Editor’s Note on the definition of T3586

13.0.0

13.1.0

2015-12

CT-70

CP-150706

0026

Multiple accesses to a PDN connection not allowed for MCM

13.0.0

13.1.0

2015-12

CT-70

CP-150706

0027

PDN modification message type

13.0.0

13.1.0

2016-03

CT-71

CP-160082

0030

1

Add cause value to WLCP

13.1.0

13.2.0

2016-03

CT-71

CP-160078

0031

1

UE requested PDN connectivity modification procedure

13.1.0

13.2.0

2016-06

CT-72

CP-160325

0033

2

PDN connectivity modification procedure

13.2.0

13.3.0

2016-06

CT-72

CP-160325

0034

Correct the direction of PDN modification accept message

13.2.0

13.3.0

2016-06

CT-72

CP-160325

0035

1

Adding NBIFOM container IE to PDN CONNECTIVITY REJECT message content

13.2.0

13.3.0

2016-06

CT-72

CP-160325

0036

1

Local release of NBIFOM PDN connection for trusted WLAN

13.2.0

13.3.0

Date

Meeting

TDoc

CR

Rev

Cat

Subject/Comment

New version

2016-09

CT#73

CP-160507

0032

4

F

non-IP PDN type not applicable in WLCP

13.4.0

2016-12

CT#74

CP-160798

0037

2

B

New emergency PDN connection in TWAN/MCM and handover of emergency PDN connection from 3GPP access to TWAN/MCM

14.0.0

2016-12

CT#74

CP-160798

0039

3

B

Additional PDN connection not allowed via trusted WLAN in MCM when using emergency service

14.0.0

2017-06

CT#76

CP-171092

0040

F

Correction to the NBIFOM container IE

14.1.0

2017-09

CT#77

CP-172123

0041

2

B

Support multiple WLCP bearers

15.0.0

2017-09

CT#77

CP-172123

0044

2

B

WLCP sublayer states for multiple bearer PDN connectivity

15.0.0

2017-09

CT#77

CP-172123

0046

1

B

WLCP bearer setup procedure for QoS differentiation

15.0.0

2017-09

CT#77

CP-172123

0047

1

B

WLCP bearer modification procedure for QoS differentiation

15.0.0

2017-09

CT#77

CP-172123

0048

1

B

WLCP bearer release procedure for Qos differentiation

15.0.0

2017-12

CT#78

CP-173082

0049

2

B

Abnormal case handling for WLCP bearer procedures

15.1.0

2017-12

CT#78

CP-173082

0051

B

TFT checking and error handling in WLCP bearer setup and modify procedures

15.1.0

2017-12

CT#78

CP-173082

0052

4

B

QoS differentiation for WLCP default bearer

15.1.0

2017-12

CT#78

CP-173082

0053

1

B

User plane identity per WLCP bearer

15.1.0

2017-12

CT#78

CP-173082

0054

B

Correction on EPS quality of service IE name

15.1.0

2017-12

CT#78

CP-173082

0055

F

WLCP bearer message name correction

15.1.0

2018-03

CT#79

CP-180091

0050

4

B

WLCP sublayer states and transition for WLCP bearers

15.2.0

2018-03

CT#79

CP-180088

0056

F

Correction on coding of PDN connection ID Information Element

15.2.0

2020-07

SA-88e

–

–

–

Update to Rel-16 version (MCC)

16.0.0

2022-03

CT-95e

CP-220224

0057

–

F

IEIs assignment for Bearer level QoS IE and APN-AMBR IE

16.1.0

2022-04

–

–

–

–

–

Update to Rel-17 version (MCC)

17.0.0