DMT API Exposure Function

DMT AEF (Diameter API Exposure Function) is an advanced API gateway designed to expose Diameter-based network functions via RESTful APIs, enabling seamless integration between 4G LTE core network elements (HSS, PCRF, OCS, DRA, etc.) and external applications, OSS/BSS, and third-party services.

Features & Benefits

API-Driven Diameter Access

Convert complex Diameter signaling (RFC 6733) into simplified RESTful APIs for seamless application integration.

Enhanced Monetization

Enable third-party developers to securely access network functions (e.g., charging, policy control, authentication) for innovative service offerings.

Real-Time Policy & Charging Control

Expose key Diameter interfaces (e.g., Gx, Gy, Ro) via APIs for dynamic QoS enforcement and billing updates.

Simplified Integration with OSS/BSS & Cloud Applications

Reduce time-to-market for new services, IoT, VoLTE, and 5G transition.

Simplify network integration without Diameter expertise

Accelerate service deployment, enable policy-driven automation, and simplify network integration

In 4G networks, DIAMETER plays a critical role in authentication, authorization, accounting, and policy control. However, directly working with the DIAMETER protocol can be complex. The DMT AEF simplifies this process for developers, offering an abstraction layer that facilitates seamless interaction with DIAMETER services.

DMT AEF enables telecom operators, MVNOs, and enterprises to expose, monetize, and manage Diameter-based services through a powerful API framework—bridging the gap between legacy 4G core networks and future 5G service ecosystems.

DMT-AEF Standalone mode: HSS, OCS, PCRF and MME connect to a DRA over S6a/S6d, Ro, Gx and S6a; the DRA connects over DIAMETER to the DMT-AEF, which exposes REST/HTTP2 APIs to APP clients.

Expose DIAMETER API to 3rd party domain with the CAPIF CF

DMT-AEF CAPIF mode, DIAMETER API with 3rd Party Exposure

DMT-AEF CAPIF mode, DMT API with 3rd Party Exposure: a 3rd party domain SERVICE#2 Application Function reaches the DMT-AEF over CAPIF-1e; SERVICE#1 connects via the DMT API; the DMT-AEF exposes CAPIF-4 to the CAPIF Core Function (CF) and connects over DIAMETER to the SCP, VLR and HLR.

MNO (Mobile Network Operator) would most typically expose APIs to MVNOs (Mobile Virtual Network Operator) to enable better integration and interoperability between their services. By exposing APIs, MNO can allow MVNO to access its network resources, such as billing, authentication, provisioning, and customer care. This can benefit both parties by reducing operational costs, improving customer satisfaction, and creating new revenue streams. For example, MVNO can offer customized plans and features to its subscribers using MNO's network infrastructure, while MNO can leverage MVNO's market reach and brand loyalty.

Technical specifications

DIAMETER

RFC 4006 - Diameter Credit-Control Application

RFC 3588 / 6733 - Diameter base Protocol

3GPP TS 32.299 - Telecommunication management; Charging management; Diameter charging applications.

DIAMETER Interfaces

S6a/S6d — HSS ↔ MME — Authentication & subscription management

Gx — PCRF ↔ P-GW — Policy control, QoS enforcement

Gy — OCS ↔ P-GW — Real-time charging, credit control

Ro — OCS ↔ IMS — Online charging for VoLTE & IMS

S9 — PCRF ↔ PCRF — Policy control for roaming

Rx — PCRF ↔ IMS AS — QoS management for VoLTE & IMS