Processing Requests

Measures for processing requests in a telecommunications network are provided. A blacklist for determining routing attempts to be conducted during a default routing attempt procedure is maintained. A request comprising an identifier for a given destination for the request is received and, in response to performing a destination address lookup for the identifier, a set of one or more destination addresses for routing the request to is received. One or more destination addresses in the set are compared to the list of destinations on the blacklist. If the comparison indicates that at least one of the destination addresses in the set is not present on the blacklist, the request is processed according to a default routing attempt procedure. If the comparison indicates that all of the destination addresses in the set are present on the blacklist, the request is processed according to an alternative routing attempt procedure.