| Russian | English |
| внутренний телефон | internal communication system |
| внутренний телефон | extension (one of the phones in a large building that have their own numbers and are connected to a switchboard (= a piece of equipment used to direct all phone calls): "Please give me a call back at extension 1247. "Can you put me through to Jan Robert's extension, please? CBED Alexander Demidov) |
| внутренний телефон | interoffice telephone |
| внутренний телефон | house phone (в учреждении, гостинице xakepxakep) |
| внутренний телефон | room-to-room telephone |
| внутренний телефон или селектор | internal communication system |