OpenAirInterface Core Network Feature Set

1. OpenAirInterface Core Network Block Diagram

2. OAI Core Network Fundamentals

• Network Access Control Functions
• Authentication and authorization
• Admission control
• Policy and charging enforcement
• Packet Routing and Transfer Functions
• IP header compression function
• Packet screening
• Mobility Management Functions
• Reachability management for UE in ECM IDLE state
• Security Functions
• Radio Resource Management Functions
• Network Management Functions (O&M)
• GTP C signaling based Load and Overload Control
• Load balancing between MME instances
• MME control of overload
• PDN Gateway control of overload

3. OAI Core Network Deployment

• Target OS
• Ubuntu 18.04 (bionic) server edition
• Red Hat Enterprise Linux 9
• Hardware Requirements
• x86-64 Intel/AMD CPU
• At least one network device
• Linux Kernel
• Generic kernel is enough
• Deployment feasible on:
• PC
• Server
• Container
• Virtual Machine

We strongly recommend a container-based deployment (either in a docker-compose fashion, or in a Kubernetes-like cluster).

4. OAI SPGW-CUPS Fundamentals

CUPS = Control-User Planes Separation

So SPGW is composed of almost 2 network functions:

• 1 SPGW-C
• 1 User Plane Function (UPF)

Multiple instances of UPF may be connected to a single instance of SPGW-C.

Fully written in C++ (-std=c++17)

• Internal design still asynchronous (ITTI based API)
• Usage of submodules: spdlog, libfolly (nolock collections)

Main differences with previous SPGW (tag v0.7.0)

• Handles GTP fragmentation
• Enables Network Address Translation (NAT), based on iptables
• Easier to install (no kernel dependencies)
• Switch-talking natively PFCP
• Data is copied/handled in user space