| 单词 | Figure P-1 |
| 释义 | Figure P-1 While some PBX systems serve the small enterprise market, that market is largely addressed by key telephone systems (KTSs). PBXs are largely intended for applications over 50–100 lines, and the very large can serve 10,000 or more lines. Such large PBXs essentially are COs with software loads providing PBX features.The 4th generation of PBXs, the IPBXs, are switched Ethernet local area networks (LANs) that support packet-switched voice, as well as data communications applications. Note: Outside North America, the term PABX (Private Automatic Branch Exchange) is often used in a generic sense to refer to a PBX. See also circuit switch, CO, common control, ECC, IPBX, KTS, line interface, power supply, SPC, switch matrix, SxS, trunk interface, and Xbar. |
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