A method of processing capacity information is disclosed, The capacity information relates to data capacity in a data network in which a consumer circuit is carried on, and consumes bandwidth made available by, a bearer circuit. The method comprises storing, in a network information database, an entity representing the bearer circuit, and associating capacity information with the bearer circuit entity specifying a first bandwidth quantity defining a quantity of bandwidth made available by the bearer circuit. Also stored is an entity representing the consumer circuit, and capacity information is associated with the consumer circuit entity specifying a second bandwidth quantity defining a quantity of bandwidth allocated to the consumer circuit. The consumer capacity information is then associated with the bearer capacity information in the database to indicate that the second bandwidth quantity allocated to the consumer circuit is to be consumed from the first bandwidth quantity made available by the bearer circuit. The resulting capacity model can be used to support service provisioning, service assurance and SLA management, network engineering and network planning processes.