| Subject | English | Portuguese |
| commun. | synchronous data link control | controlo de ligação de dados síncrono |
| comp., MS, Braz. | synchronous data link control | protocolo SDLC (A type of link service used for managing synchronous data transfer over standard telephone lines (switched lines) or leased lines. The data transmission protocol most widely used by networks conforming to IBM's Systems Network Architecture (SNA). SDLC is similar to the HDLC (High-level Data Link Control) protocol developed by the International Organization for Standardization (ISO)) |