The present invention relates to a method and an arrangement for centralized and distributed management of the capacity in a circuit-switched network with a bus or ring structure, especially a network of DTM-type (Dynamic Synchronous Transfer Mode), which network uses a bandwidth which is partitioned in cycles, which in turn are partitioned in control time slots for signalling and data time slots for transfer of data, and wherein each data time slot is associated with a token. In the centralized version, a first node, called server node, is allocated tokens corresponding to all data time slots which are flowing in one direction in a bus or a ring. A second node is requesting tokens corresponding to a certain capacity from the server node, and the server node makes reservations for and transfers tokens corresponding to requested capacity to the other node in event the server node has requested capacity unutilized. The number of server nodes in the distributed version is between two and the total number of nodes in the bus or ring.