!!! Overview
[{$pagename}] ([PSTN], [POTS]) is the aggregate of the world's [Circuit switching] telephone [networks] that are operated by national, regional, or local telephony operators, providing infrastructure and services for public [telecommunication]. At the turn of the 21st century, the oldest parts of the telephone [network] still use analog technology for the [Last Mile Loop] to the end user. However, [Digital Communications]  such as [DSL], [ISDN], [FTTx], and [cable modems] have become more common in this portion of the [network].

Several large private telephone [networks] are not linked to the [PSTN]. Some of these are:
* military purposes. 
* large [Private Branch Exchange] ([PBX]).

!! More Information
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