1. Information technology. International standardized profile RC. X.25 protocol relaying. Definition of profile RC51.1121, X.25 protocol relaying between CSMA/CD LAN subnetworks and PSDNs using virtual calls over a digital data circuit/CSDN leased line permanent access Part 6, (15th September 1995) Authors: British Standards Institution, Record Type: Book Extent: 1 online resource (12 pages) View Content: Available online (eLD content is only available in our Reading Rooms) ↗