Application ID

Name

Description

Specification

0

Diameter common message

Diameter is a protocol designed to handle authentication, authorization, and accounting (AAA) for network access, IP mobility, and various other applications. Common messages are associated with the Application ID of 0, meaning they are applicable universally across all Diameter applications.

[RFC6733]

4

Diameter Credit-
Control Application

Diameter Credit-Control Application provides a framework for implementing real-time credit control in various telecommunication services. This application is essential in environments where services are delivered to end users based on prepaid accounts or where real-time cost and credit management are required. The key functionality of the Diameter Credit-Control Application is to ensure that the user’s account has sufficient funds to cover the cost of services before they are initiated and to manage ongoing service costs in real time.

[RFC8506]

-

Ericsson

SCAPv2

SCAPv2 (Service Charging Application Protocol version 2) interface is a part of Ericsson's Diameter-based service architecture, designed to facilitate real-time charging and cost control for services provided to users. It is specifically used in conjunction with the Diameter Credit Control (DCC) protocol, which handles the real-time accounting of service usage, ensuring that users have sufficient credit before a service is delivered.

-

-

Huawei Diameter Credit-
Control

Huawei Diameter Credit-Control (DCC) interface is a specialized application protocol derived from the general Diameter protocol. It is designed to handle real-time credit control for a variety of user services, such as network access, SIP-based communication, and other real-time services that require immediate billing verification.

-

16777216

Cx/Dx

Cx and Dx interfaces are part of the IMS (IP Multimedia Subsystem) architecture, which is used for delivering IP multimedia services. These interfaces facilitate communication between the Call Session Control Functions (CSCFs) and the Home Subscriber Server (HSS) or Subscriber Location Function (SLF).

[3GPP TS 29.229]

16777231

E4

E4 interface is a component within the Resource and Admission Control Subsystem (RACS) architecture, used to facilitate the exchange of IP-connectivity session data between the Network Attachment Subsystem (NASS) and RACS. This exchange ensures efficient resource allocation and admission control for IP-based services.

[ETSI ES 283 034]

5

EAP

Extensible Authentication Protocol (EAP) is an authentication framework that supports multiple authentication mechanisms. EAP can be used on dedicated links, switched circuits, and both wired and wireless links. The Diameter EAP application is based on the Diameter Network Access Server Application (NASREQ) and is intended for environments similar to NASREQ.

[RFC4072]

1

Gi

Gi interface is a part of the GPRS (General Packet Radio Service) network, enabling communication between the Gateway GPRS Support Node (GGSN) and external packet data networks (PDNs), such as the Internet. This interface handles the secure and efficient transmission of user data between the mobile network and external networks, allowing users to access services like the Internet from their mobile devices.

[3GPP TS 29.061]

16777223

Gmb

Gmb interface in the GPRS network facilitates communication between the Gateway GPRS Support Node (GGSN) and the Broadcast-Multicast Service Center (BM-SC). This interface is specifically designed to support the delivery and management of MBMS (Multimedia Broadcast Multicast Services) bearer services.

[3GPP TS 29.061]

16777222

Gq

Gq interface facilitates communication between the Application Function (AF) and the Policy Decision Function (PDF), enabling the dynamic enforcement of QoS policies that align with the service requirements of the application. It’s an important component within IP multimedia networks, particularly for managing Quality of Service (QoS) in scenarios where services like Voice over IP (VoIP), video streaming, or other real-time multimedia applications are involved.

[3GPP TS 29.209]

[3GPP TS 29.208]

16777222

Gq’

Gq' interface is specifically designed for service-based policy setup and resource reservation in fixed broadband access networks. It facilitates the exchange of policy-related information between two key functional entities: the Service-Based Policy Decision Function (SPDF) and the Application Function (AF).

[ETSI TS 183 017]

16777238
in LTE networks

16777224
in pre-LTE 3G networks

Gx

Gx interface facilitates communication between the Policy and Charging Rules Function (PCRF) and the Policy and Charging Enforcement Function (PCEF), enabling the dynamic enforcement of Quality of Service (QoS) policies and charging rules for user sessions.

[3GPP TS 29.212]

[3GPP TS 29.210]

16777266

Gxx

Gxx interface facilitates communication between the Policy and Charging Rules Function (PCRF) and the Bearer Binding and Event Reporting Function (BBERF). The Gxx interface is particularly important in scenarios involving Access Network Gateways, such as the Serving Gateway (S-GW) in LTE networks, or in trusted non-3GPP access networks.

[3GPP TS 29.212]

14

Gy

Gy interface is a component in the 3GPP-defined online charging system (OCS), connecting the Policy and Charging Enforcement Function (PCEF) to the Online Charging System (OCS). This interface is responsible for enabling real-time, session-based charging in mobile networks.

[3GPP TS 32.251]

16777335

M2B-C

MB2-C interface serves as a control-plane interface facilitating communication between the Group Communication Service Application Server (GCS AS) and the Broadcast-Multicast Service Centre (BM-SC).

[3GPP TS 29.468]

16777226

MM10

MM10 interface facilitates communication between the MMS Relay/Server and the Multimedia Service Control Function (MSCF). The primary function of the MM10 interface is to manage the processing and delivery of multimedia messages (MMS).

[3GPP TS 29.140]

1

Diameter Network Access Server (NAS) Application

Diameter Network Access Server (NAS) Application is designed to facilitate Authentication, Authorization, and Accounting (AAA) services within a NAS environment. NAS environments typically include network devices such as routers, switches, and firewalls that provide access to a network.

[RFC7155]

16777342

Np

Np interface facilitates communication between the Radio Access Network Congestion Awareness Function (RCAF) and the Policy and Charging Rules Function (PCRF). It plays a key role in handling congestion-related information and user equipment (UE) mobility within the network.

[3GPP TS 29.217]

16777348

Nt

Nt interface enables communication between the Policy and Charging Rules Function (PCRF) and the Service Capability Exposure Function (SCEF). This interface facilitates the transfer of data transfer policies and is particularly relevant in IoT (Internet of Things) environments where efficient and regulated data communication is essential.

[3GPP TS 29.154]

16777358

Nta

Nta interface facilitates communication between the Policy and Charging Rules Function (PCRF) and the Service Capability Exposure Function (SCEF). The Nta interface is specifically designed for configuring event monitoring for a group of User Equipment (UEs) and reporting those events.

[3GPP TS 29.154]

16777337

PC2

PC2 interface is a part of the Proximity Services (ProSe) architecture, which enables devices (UEs) to discover and communicate with each other when they are in close proximity. The PC2 reference point facilitates communication between the ProSe Application Server and the ProSe Function, allowing for the implementation of ProSe features such as direct discovery and EPC-level ProSe discovery.

[3GPP TS 29.343]

16777336

PC4a

PC4a interface within the 3GPP Proximity Services (ProSe) architecture, specifically designed for communication between the ProSe Function and the Home Subscriber Server (HSS). This interface manages Diameter-based signaling for ProSe services, focusing on message prioritization and load control.

[3GPP TS 29.344]

16777340

PC6/PC7

PC6/PC7 interfaces enable communication between ProSe Functions located in different PLMNs (Public Land Mobile Networks), specifically between the Home PLMN (HPLMN) and local or visited PLMNs. The primary purpose of these interfaces is to support service authorization and management for ProSe services, such as ProSe Direct Discovery and communication.

[3GPP TS 29.345]

4

Rf

Rf interface is a component within the 3GPP network architecture, specifically designed for offline charging in the Packet-Switched (PS) domain. It is responsible for facilitating the transmission of Charging Data Records (CDRs) from network elements to the Charging Data Function (CDF) for subsequent processing, storage, and billing purposes.

[3GPP TS 29.251]

[3GPP TS 29.299]

2

Diameter Mobile IPv4 Application

Diameter Mobile IPv4 Application is an essential protocol for supporting Mobile IPv4 services within the context of Authentication, Authorization, and Accounting (AAA) operations. This application facilitates seamless mobility management for Mobile Nodes (MNs) as they move across different administrative domains while maintaining a constant IP address. This includes verifying the identity of a Mobile Node (MN), authorizing its access to network resources, and accounting for its usage while connected to the network.

[RFC4004]

6

Diameter Session Initiation Protocol (SIP) application

Diameter Session Initiation Protocol (SIP) application, designed to support SIP-based IP multimedia services. The primary purpose of this application is to facilitate the authentication, authorization, and accounting (AAA) of SIP sessions, ensuring that only authorized users can initiate or receive SIP-based communications, such as VoIP calls or video conferences.

[RFC4740]

7

in IKEv2 scenarios

8

in Mobile IPv6 Authentication Protocol scenarios

Diameter Mobile IPv6 (MIPv6)

Diameter Mobile IPv6 (MIPv6) interface ensures that mobile nodes (MNs), which move across different networks are properly authenticated, authorized, and accounted for, while maintaining a consistent IP address.

[RFC5778]

3

Ro

Ro interface is designed to handle real-time online charging in telecommunications networks. The Ro interface is used to facilitate communication between the Charging Trigger Function (CTF) and the Online Charging Function (OCF), allowing operators to manage charging events and credit control in real-time.

[3GPP TS 29.251]

[3GPP TS 29.299]

16777236

Rx

Rx interface facilitates communication between the Application Function (AF) and the Policy and Charging Rules Function (PCRF). The primary purpose of the Rx interface is to exchange application-level session information, enabling the PCRF to make informed policy and charging decisions that align with the specific needs of a service session and the subscriber's profile.

[3GPP TS 29.214]

16777252

S13

S13 interface facilitates secure communication between the Mobility Management Entity (MME) or Serving GPRS Support Node (SGSN) and the Equipment Identity Register (EIR). This interface is primarily used for the Mobile Equipment (ME) Identity Check Procedure, ensuring that mobile devices attempting to access the network are legitimate, not stolen, and comply with network policies. The main purpose of the S13 interface is to verify the identity of mobile devices through their International Mobile Equipment Identity (IMEI).

[3GPP TS 29.272]

16777318

S15

S15 interface is a component in the management of Quality of Service (QoS) within the Home Node B (HNB) and Fixed Broadband Access Network environments. This interface enables communication between the HNB Gateway (HNB GW) and the Policy and Charging Rules Function (PCRF) or Virtualized PCRF (V-PCRF). The primary function of the S15 interface is to facilitate the dynamic provisioning, modification, and removal of QoS rules, ensuring that network resources are optimally allocated for HNB circuit-switched (CS) calls.

[3GPP TS 29.212]

16777251

S6a

S6a interface is an element in the LTE architecture, enabling communication between the Mobility Management Entity (MME) and the Home Subscriber Server (HSS). The S6a interface utilizes the Diameter protocol to securely exchange subscriber-related data, ensuring that services are provided seamlessly as users move within the network. S6a interface supports functions like user authentication, location management, and subscription data handling.

[3GPP TS 29.272]

16777272

S6b

S6b interface is a component in the architecture of the Diameter protocol, designed to facilitate communication between the 3GPP AAA Server and the Packet Data Network Gateway (PDN-GW) within the Evolved Packet Core (EPC) of a mobile network. The primary purpose of the S6b interface is to support the authentication, authorization, and mobility management of User Equipment (UE) accessing the network via non-3GPP access technologies such as Wi-Fi.

[3GPP TS 29.273]

16777312

S6c

S6c interface is a component of the Diameter protocol, specifically designed to facilitate the communication between the Home Subscriber Server (HSS) and central Short Message Service (SMS) functions such as the SMS Gateway Mobile Switching Center (SMS-GMSC) and the IP Short Message Gateway (IP-SM-GW). S6c interface is used for managing the routing of SMS messages within both traditional and IP-based mobile networks.

[3GPP TS 29.338]

16777310

S6m

S6m interface is a component of the Diameter protocol architecture, specifically designed for Machine-Type Communication (MTC) systems. S6m reference point establishes communication between the Machine-Type Communication Interworking Function (MTC-IWF) and the Home Subscriber Server (HSS). This interface is used for managing the lifecycle, authentication, authorization, and service requests for MTC devices within the network. The HSS is responsible for storing and managing the subscription data, which can include a variety of MTC devices such as sensors, or other IoT devices.

[3GPP TS 29.336]

16777345

S6t

S6t interface is an element in the 3GPP architecture for managing Machine-Type Communication (MTC) devices, particularly in the context of the Internet of Things (IoT). S6t interface enables communication between the Service Capability Exposure Function (SCEF) and the Home Subscriber Server (HSS). The primary purpose of the S6t interface is to facilitate the configuration, monitoring, and management of MTC devices by allowing the SCEF to interact with the HSS. S6t supports various functions such as the configuration of monitoring events, management of communication patterns, and the retrieval of subscription data.

[3GPP TS 29.336]

16777308

S7a

S7a interface is an element within the Diameter protocol, enabling the transfer of subscriber-related Closed Subscriber Group (CSG) data between the Mobility Management Entity (MME) and the Closed Subscriber Group Subscription Server (CSS) within a Visited Public Land Mobile Network (VPLMN). Similarly, the S7d interface serves the same purpose but operates between the Serving GPRS Support Node (SGSN) and the CSS. This interface is important in scenarios where users are moving between different network areas, such as during handovers between cells in a VPLMN, to ensure that their subscription data is up-to-date and that they can access the CSGs to which they are entitled.

[3GPP TS 29.272]

16777267

S9

S9 interface is used in roaming scenarios involving a Home Public Land Mobile Network (HPLMN) and a Visited Public Land Mobile Network (VPLMN). The primary function of the S9 interface is to facilitate communication between the Home Policy and Charging Rules Function (H-PCRF) in the HPLMN and the Visited Policy and Charging Rules Function (V-PCRF) in the VPLMN. In addition to transmitting PCC, QoS, and ADC rules, the S9 interface enables the H-PCRF to receive reports from the V-PCRF about the status of these rules in the visited network. This allows the H-PCRF to maintain control over the user's session even when they are not in their home network.

[3GPP TS 29.215]

16777319

S9a

S9a interface is designed specifically for Fixed Broadband Access Network (FBAN) interworking within the Policy and Charging Control (PCC) architecture. It enables the transfer of Quality of Service (QoS) and Policy and Charging Control (PCC) rules between the Broadband Policy Control Function (BPCF) in the Fixed Broadband Access Network and the Policy and Charging Rules Function (PCRF) in the Packet Data Network (PDN). The S9a interface is primarily used in scenarios where there is a need to manage and enforce policy control and QoS for users accessing services over a fixed broadband network.

[3GPP TS 29.215]

16777320

S9a*

S9a* protocol is an extension of the S9a interface specifically designed to support Non-Seamless Wireless Offload (NSWO) scenarios in the context of interworking between a Policy and Charging Rules Function (PCRF) and a Broadband Policy Control Function (BPCF). It operates similarly to S9a but with additional AVPs to handle the unique requirements of non-seamless offloading.

[3GPP TS 29.215]

16777303

Sd

Sd interface is a component of the Policy and Charging Control (PCC) architecture. This interface is established between the Policy and Charging Rules Function (PCRF) and the Traffic Detection Function (TDF). It is used for the detection, reporting, and control of application-specific traffic within the network. The Sd interface facilitates real-time exchange of Application Detection and Control (ADC) rules and associated information between the PCRF and the TDF.

[3GPP TS 29.212]

16777313

SGd

SGd interface is used to facilitate the transfer of short messages (SMS) between the Mobility Management Entity (MME) and central SMS functions such as the SMS Interworking Mobile Switching Center (SMS-IWMSC), the SMS Gateway MSC (SMS-GMSC), and the SMS Router. The SGd interface enables these entities to exchange SMS-related signalling, ensuring the efficient delivery and management of SMS services within the network.

[3GPP TS 29.338]

16777292

SGmb

SGmb interface in the Diameter protocol is used for communication between the Multimedia Broadcast Multicast Service Gateway (MBMS-GW) and the Broadcast Multicast Service Center (BM-SC). This interface is used for managing and controlling MBMS sessions in E-UTRAN/UTRAN networks. The primary purpose of the SGmb interface is to facilitate the start, update, and stop of MBMS sessions, and allows the BM-SC and MBMS-GW to monitor the integrity of the MBMS data paths. The SGmb interface is also used for transferring local MBMS information related to the M1 interface, which for synchronizing and managing MBMS services across the network.

[3GPP TS 29.061]

16777217

Sh

Sh interface is a component of the IP Multimedia Subsystem (IMS) architecture. It facilitates communication between the Home Subscriber Server (HSS) and various Application Servers (AS), enabling the exchange of user-related data necessary for service provision. This includes the retrieval, updating, and notification of user profile data, for delivering personalized services in an IMS network.

[3GPP TS 29.328]

16777255

SLg

SLg interface is a component within the Evolved Packet Core (EPC) that facilitates location-based services (LBS). It operates between the Gateway Mobile Location Center (GMLC) and the Mobility Management Entity (MME) or Serving GPRS Support Node (SGSN). The primary function of the SLg interface is to enable the exchange of location information between these network elements to support various location services.

[3GPP TS 29.172]

16777291

SLh

SLh interface is used for supporting Location Services (LCS) within GSM, UMTS, and EPS networks. The SLh interface facilitates communication between the Gateway Mobile Location Center (GMLC) and the Home Subscriber Server (HSS). It primarily functions to enable the GMLC to obtain routing information necessary for locating a mobile subscriber (UE) within the network.

[3GPP TS 29.173]

16777349

St

St interface is a component within the Policy and Charging Control (PCC) architecture. It facilitates communication between the Policy and Charging Rules Function (PCRF) and the Traffic Steering Support Function (TSSF). The primary role of the St interface is to convey traffic steering control information from the PCRF to the TSSF, allowing the network to dynamically manage and steer user traffic based on pre-defined policies.

[3GPP TS 29.212]

16777250

STa

STa interface facilitates communication between non-3GPP access networks and the 3GPP AAA server or 3GPP AAA proxy. It is primarily used for authenticating and authorizing User Equipment (UE) accessing the Evolved Packet Core (EPC) through non-3GPP networks, whether these networks are trusted or untrusted. The STa interface also supports the transport of various mobility-related parameters, including PMIPv6, GTPv2, and MIPv4 FA-CoA modes. Additionally, the interface can convey charging-related information.

[3GPP TS 29.273]

-

SWa

SWa interface facilitates communication between an untrusted non-3GPP IP access network and the 3GPP AAA Server or Proxy. Its primary function is to manage the authentication and authorization processes for User Equipment (UE) attempting to connect to the Evolved Packet System (EPS) via these untrusted networks. This interface is used to ensure that only authorized devices can access the EPS.

[3GPP TS 29.273]

-

SWd

SWd interface is designed to facilitate communication between the 3GPP AAA Proxy and the 3GPP AAA Server. The SWd interface handles multiple operational aspects, including user authentication, session authorization, charging information, and key management for encryption and integrity protection, tunnel establishment and user identifier mapping to tunnel identifiers.

[3GPP TS 29.273]

16777264

SWm

SWm interface in the 3GPP architecture, is designed to facilitate communication between the evolved Packet Data Gateway (ePDG) and the 3GPP AAA Server or 3GPP AAA Proxy. This interface is essential for managing security, authentication, and mobility for UE that connects to the Evolved Packet Core (EPC) through untrusted non-3GPP access networks, such as Wi-Fi.

[3GPP TS 29.273]

16777265

SWx

SWx interface is utilized by the 3GPP AAA Server to authenticate and authorize UE when accessing the network via non-3GPP IP access points. The interface ensures that the UE is properly authenticated, and its access to network resources is authorized based on the user’s subscription profile stored in the HSS. SWx interface supports the transfer of mobility-related parameters, particularly when Network-Based Mobility (NBM) is employed. It updates the HSS with the PDN Gateway (PDN-GW) address information, which is necessary for establishing and maintaining connectivity to the Evolved Packet Core (EPC). SWx interface is responsible for updating the HSS with the current AAA Server address each time a UE connects to a non-3GPP access network.

[3GPP TS 29.273]

[3GPP TS 23.402]

16777302

Sy

Sy interface is primarily designed to facilitate communication between the Policy and Charging Rules Function (PCRF) and the Online Charging System (OCS). The primary purpose of the Sy interface is to enable the PCRF to make informed policy decisions by retrieving subscriber spending limit information from the OCS. Sy interface is used in scenarios where the PCRF needs to adjust policy decisions dynamically based on a subscriber's spending behaviour, ensuring that the network enforces appropriate charging rules and quality of service (QoS) settings.

[3GPP TS 29.219]

16777311

T4

T4 interface is designed for communication between the Machine Type Communication Interworking Function (MTC-IWF) and the Short Message Service Service Center (SMS-SC) within a Home Public Land Mobile Network (HPLMN).

The primary purpose of the T4 interface is to facilitate the transfer of device trigger messages from the MTC-IWF to the SMS-SC. This interface ensures that critical information, such as the identities of serving network elements (e.g., SGSN, MME, MSC, SMSF), is conveyed accurately to the SMS-SC. The SMS-SC then processes these triggers and attempts to deliver them to the intended user equipment (UE).

[3GPP TS 29.337]

16777346

T6a

T6a interface connects the Mobility Management Entity (MME) or Serving GPRS Support Node (SGSN) with the Service Capability Exposure Function (SCEF). This interface is designed to facilitate communications between network elements, particularly for supporting Machine-Type Communication (MTC) and Internet of Things (IoT) services. T6a interface allows the MME/SGSN to report various monitoring events to the SCEF. SCEF uses the T6a interface to configure specific monitoring events within the MME/SGSN.

[3GPP TS 29.128]

16777309

Tsp

Tsp interface facilitates communication between the Service Capability Server (SCS) and the Machine Type Communication Interworking Function (MTC-IWF) within the 3GPP network, specifically for Machine-Type Communication (MTC) services. The Tsp interface enables the SCS, which manages MTC applications, to interact with the MTC-IWF to perform actions like device triggers, message forwarding, and notifications within the network.

[3GPP TS 29.368]