We have constructed an optical 2-to-1 packet multiplexor for use in the next generation of digital networks. It has a clear advantage over conventional electronic network nodes because it can support any bit rate, theoretically up to the full bandwidth of a fiber. Since it switches on a packet-by-packet basis, the control electronics are simple and inexpensive. The multiplexor uses electronically-addressed 2 × 2 lithium niobate directional coupler switches to route packets and lengths of fiber to buffer contentious packets. The multiplexor can be cascaded to form a larger 2-to-1 multiplexor with improved packet loss performance. We present theoretical and simulated results (including packet loss rate and optical insertion loss) for this multiplexor. We also contrast the performance of the multiplexor for slotted input versus unslotted input.