 He was acknowledged by Cerf and Bob Kahn in their 1974 paper on internetworking, ""A Protocol for Packet Network Intercommunication"," and he co-authored the standard agreed by the INWG in 1975, ""Proposal for an international end to end protocol"".Later, as head of the data networks group within the Computer Science Division, he was responsible for the UK technical contribution to the European Informatics Network, a datagram network linking CERN, the French research centre INRIA and the UK’s National Physical Laboratory.He joined Logica in 1977 in their Communications Division, where he worked on the CCITT (ITU-T) X.25 protocol and with the formation of the Euronet, a virtual circuit network using X.25.