The services offered (e.g., bandwidth) by a PVC can be changed, potentially as and when desired. An end system (of a PVC) may send a request to initiate a change of a service. Each intermediate system may first determine whether the service change can be supported, and passes the request to the next system in the path until the request is received by the other end system of the PVC. Assuming the other end system also can support the change, an acceptance response is propagated in the reverse direction of the same path. Each system may effect the service change upon receiving the acceptance response.