Method and system for reconfiguration of an interface

The invention concerns a method and a system for redefinition of the configuration of an interface in a telecommunication system comprising a local exchange, and access node, subscriber ports comprised in said network elements and an interface connecting the subscriber ports of the first network element to the subscriber ports of the second network element. In the method, free subscriber ports are blocked and the configuration of the interface is redefined after all the subscriber ports have been blocked. According to the invention, a connection established or being established via the subscriber port is disconnected before the port is blocked. The system of the invention comprises means for disconnecting a connection established or being established via the subscriber port.