The Cisco SM-X-ES3-16-P is a switch module manufactured by Cisco for the ISR 4000 Series. It features a network interface of 16 x 1 Gigabit Ethernet PoE+ RJ45 ports in an internal service module (SM) form factor, supporting data transmission speeds up to 1 Gbps per port.

This model integrates with compatible devices such as the Cisco ISR 4451-X router. The switch provides sixteen powered Ethernet interfaces that support IEEE802.3at PoE+, supplying power and connectivity through standard Cat5e or higher cabling without requiring separate power lines. Suitable for routing scenarios that require local switching within branch routers, it installs internally in supported chassis models and uses backplane integration rather than external mounting brackets or rack ears.