5G Roaming architecture can be LBO (Local Breakout) Roaming, or HR (Home Routed) Roaming.

The main difference between them, is how they handle user data, and the responsible network elements.

LBO (Local Breakout) Roaming

• It establishes the user's PDU session in the visited network.

• User data traffic move directly from the User Plane Function (UPF) in the visited network to the external data network, without going through the home network.

• SMF and UPF in the visited network handle the user's session management and user plane functions, respectively.

• LBO roaming can provide lower latency and more efficient data transmission, as the user data does not need to traverse the home network.

HR (Home Routed) 5G Roaming

• It establishes the user's PDU session in the home network.

• User data traffic move through the home network, passing through the Home UPF before reaching the external data network.

• SMF in the home network handles the user's session management. While the Home UPF in the home network handles the user plane functions.

• HR roaming provides better control and visibility over the user's data traffic for the home network operator, as the data traverses the home network.