A hub node for a wavelength division multiplexed, WDM, optical network configured to automatically discover at least one of new client-side optical ports (30, 30A, 30B, 30C) at client nodes (20, 20A, 20B, 20C) and new edge-side optical ports (33, 33A, 33B, 33C) at service edge nodes (32, 32A, 32B, 32C), the hub node comprising: a wavelength switch network configured to route any wavelength channel (CH1, CH2) that supports a matching pair of client-side and edge-side optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) between those ports, and to route any wavelength channel (CH1, CH2) that does not support such a matching pair to a port discovery equipment of the hub node; wherein the port discovery equipment is configured to: search for new client-side or edge-side optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) by scanning for the presence of a predefined signal on wavelength channels (CH1, CH2) routed to the port discovery equipment; and responsive to finding a new optical port (30, 30A, 30B, 30C, 33, 33A, 33B, 33C), automatically discover a predefined set of one or more attributes of the new optical port (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) by inspecting the predefined signal on the wavelength channel (CH1, CH2) supporting that optical port (30, 30A, 30B, 30C, 33, 33A, 33B, 33C); and a controller configured to determine that a client-side optical port (30, 30A, 30B, 30C) and an edge-side optical port (33, 33A, 33B, 33C) are the matching pair of optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) if discovered sets of attributes of those ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) match according to one or more predefined rules, and to dynamically control the wavelength switch network to re-route the wavelength channel supporting that matching pair of optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) between those optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) rather than to the port discovery equipment. a wavelength switch network configured to route any wavelength channel (CH1, CH2) that supports a matching pair of client-side and edge-side optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) between those ports, and to route any wavelength channel (CH1, CH2) that does not support such a matching pair to a port discovery equipment of the hub node; wherein the port discovery equipment is configured to: search for new client-side or edge-side optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) by scanning for the presence of a predefined signal on wavelength channels (CH1, CH2) routed to the port discovery equipment; and responsive to finding a new optical port (30, 30A, 30B, 30C, 33, 33A, 33B, 33C), automatically discover a predefined set of one or more attributes of the new optical port (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) by inspecting the predefined signal on the wavelength channel (CH1, CH2) supporting that optical port (30, 30A, 30B, 30C, 33, 33A, 33B, 33C); and search for new client-side or edge-side optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) by scanning for the presence of a predefined signal on wavelength channels (CH1, CH2) routed to the port discovery equipment; and responsive to finding a new optical port (30, 30A, 30B, 30C, 33, 33A, 33B, 33C), automatically discover a predefined set of one or more attributes of the new optical port (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) by inspecting the predefined signal on the wavelength channel (CH1, CH2) supporting that optical port (30, 30A, 30B, 30C, 33, 33A, 33B, 33C); and a controller configured to determine that a client-side optical port (30, 30A, 30B, 30C) and an edge-side optical port (33, 33A, 33B, 33C) are the matching pair of optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) if discovered sets of attributes of those ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) match according to one or more predefined rules, and to dynamically control the wavelength switch network to re-route the wavelength channel supporting that matching pair of optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) between those optical ports (30, 30A, 30B, 30C, 33, 33A, 33B, 33C) rather than to the port discovery equipment.