IP/MPLS basics for mobile networks

Why Mobile Networks Run on IP/MPLS

Modern mobile transport networks rely on IP/MPLS to carry traffic between cell sites and the mobile core. Multiprotocol Label Switching adds a thin shim header between the Layer 2 and Layer 3 headers, enabling routers to forward packets based on fixed-length labels rather than performing a full IP longest-prefix-match lookup at every hop. This label-based forwarding provides deterministic paths, traffic engineering capabilities, and service separation that raw IP routing cannot easily deliver. For mobile operators, IP/MPLS creates a unified transport fabric that carries 4G S1, 5G N2/N3,…