1. Information systems interconnection. X.25 protocol relaying. Profile RC51.1121 (M-IT-02 R/32 over digital data circuit/CSDN leased line) Part 6, (15th November 1992) Authors: British Standards Institution, Record Type: Book Extent: 1 online resource (10 pages) View Content: Available online (eLD content is only available in our Reading Rooms) ↗