Method and apparatus for improved handling of IMS node blacklisting

Accordingly, there is provided an IMS node, comprising a transmission module and a processor. The transmission module is arranged to send SIP messages to a plurality of other IMS nodes. The processor arranged to detect an error in a particular other IMS node, the error indicating that the particular other IMS node is not available to receive traffic. In response to detection of such an error, the processor causes the particular other IMS node not to be used for a period of time. The transmission module is further arranged to send at least one test message to the particular other IMS node when the period of time expires. The processor is further arranged to determine if the at least one test message is successfully processed by the particular other IMS node, and in response to a positive determination then returning the particular other IMS node to use.