The BroadForward Service Communication Proxy (SCP) is a crucial component in the 5G network architecture that functions as an intermediary to enhance communication between different network functions (NFs). By facilitating service-based interactions, the SCP optimizes the discovery, routing, and load balancing of these communications, ensuring efficient resource utilization and improved network performance. It acts as a broker, providing features such as security, scalability, and resilience, thereby streamlining the service-oriented architecture inherent to 5G networks and supporting the dynamic, high-demand environment required by advanced 5G applications.
The role of the Service Communication Proxy
The SCP is a new HTTP/2 based network function enabling dynamic scaling and management of communication and services in the 5G network. The SCP plays a role that can be compared to its predecessors, such as the Signaling Transfer Point (STP), the central signaling router used in 2G/3G to route SS7 signaling messages, as well as the Diameter Signaling Controller (DSC) doing the same for Diameter messages in 4G. A key difference with these legacy routers is that the SCP can be responsible for resolving Network Function (NF) discovery requests via communication with the Network Repository Function (NRF), and can initiate Domain Name Server (DNS A-record) IP address lookups to a DNS to locate every live instance for every available Network Function.
BroadForward SCP
The BroadForward Service Communication Proxy (SCP) plays an important role within the 5G Service Based Architecture (SBA), providing functions ranging from simplifying network topology by applying signaling aggregation and routing, to load balancing, overload handling and message parameter harmonization as well as interworking with legacy systems such as the STP and DRA-DEA and with other 5G functions such as BSF and 4G-5G interworking.
The BroadForward SCP supports indirect communications, mediating messages between service consumers and producers, in accordance with 3GPP Release-16 Model C and D. In Model C, the consumer NF communicates directly with the NRF to discover the target producer NFs, and then uses SCP to route the requests; in Model D however, the NF producer discovery and selection are delegated to the SCP.
Functions of the BroadForward SCP include:
- NRF registration for SCP
- Support for transport layer security (TLS) up to version 1.3
- Providing a single point of entry (or exit) for a cluster of a given type of NFs
- Message forwarding, routing and load balancing of HTTP service requests
- Message parameter harmonization
- Overload control, Egress/Ingress limitation
- Optional UDR resolution (subscriber lookup)
- SCP TS 23.501 Model C support
- NRF service discovery, subscription and notification
- NF service authorization
- Delegated Discovery for NRF, Delegated NF Service (de)registration, TS 23.501 Model D support
- OAuth2 support for peer authentication
- Onboard gRPC interface support for HTTP traffic monitoring & forwarding, enabling direct integration with network monitoring and analysis systems
- 4G-5G IWF for maintaining legacy support for 5G SA (e.g. interworking with 4G OCS and PCRF)
- Supporting high-available and geo-redundant deployment models
- Full GUI-based signaling orchestration and system management, configurable service logic, no need for scripting or development
- Extendable with other BroadForward 5G network functions, such as BSF and SEPP
- Optional BSF allows NF service consumers (e.g. PCF) to register, update and remove binding information related to specific PDU sessions
Combining network functions
The BroadForward SCP runs on a unique single engine software architecture called BFX, allowing operators to combine multiple networks functions on the same platform, such as SEPP, STP, DRA and BSF. This provides many benefits, such as:
- Reduction of integration points, and on-board capability for interworking and interoperability
- Centralized and uniform IT integration, signaling management, configuration, provisioning, subscriber management, reporting and control
- Centralized and uniform use of common network applications (e.g. firewall, number portability, steering of roaming)
- Easy to operate, uniform operations across domain technologies
- Single capacity license with free traffic mix across supported protocols
Virtualized, cloud-based and containerized deployment
The BroadForward SCP provides unmatched flexibility with various deployment options, including bare metal, virtual machines, containers, and cloud environments, all while maintaining a low resource footprint. This 100% software-based, hardware-agnostic solution eliminates the need for specialized hardware or proprietary operating systems. Deploying the BroadForward SCP on a common platform facilitates the transition for operators and vendors from proprietary appliance systems to a standardized, hardware-agnostic, software-only infrastructure.