Abstract: Communications trails on a network can be provisioned by users using a trail manager. In a hierarchically-layered connection-management domain, when a trial (50) between trial termination points having respective adaptation capabilities is provisioned, client links (52,54,56) within the intersection of those adaptation capabilities are created. Further trails may then be provisioned in channels within those client links. Channel usage information (58,60,62) within the client links is recorded to indicate current channel usage and this information is updated by the trail manager whenever a trial using a channel is added or deleted. In a hierarchically-layered domain, channels within client-links corresponding to different adaptation capabilities, such as different data rates, may overlap and so when channel-usage information in one client link is updated, channel-usage information in other client links is also considered and updated as appropriate.