POTS is the name for the original analog telephone connection and stands for Plain Old Telephone Service, Post Office Telephone Service or Post Office Telephone System. Definition Depending on the interpretation, this can have the following (conflicting) meanings: In the rest of this article, we will start from the first definition, as it is most consistent with the definition of other terms. Note that the term PSTN is often also used as “analog counterpart to ISDN”. However, this definition is incorrect. PSTN is the name for the entire telephone network (analog or digital), while ISDN only refers to the end points of this. Consequently, it makes sense to use POTS in the first definition above so that it refers to the analog endpoints. Thus, in this terminology, the entire telephone network is PSTN (analog or (nowadays fully) digital), and this has user endpoints as either POTS (analog) or ISDN (digital). Signals All signals pass over only two conductors (except ground): […]

Digital telephony

Digital telephony is a fairly general term for telephone traffic that is transported in a digital way. The original analog telephone network has been digitized since the 1980s. Network digitization Circuit switched analog telephone network In the original analog telephone network, copper wire connections were connected to a telephone exchange. The telephone exchange was responsible for making the connection and was previously connected to other exchanges. Several conversations could be conducted over one copper wire by means of frequency multiplexing, that is to say, each call received part of the available frequency space available on the wire. The analog telephone network was a circuit switched network, which means that a fixed communication channel is built up from the caller to the called party. Digital networks have advantages over an analog network, but the biggest advantage of a digital network is the sound quality; with an analog telephone network, the sound quality decreases the further away the interlocutor is, with a […]

Asterisk PBX

Asterisk is an open source telephony platform for Mac, Linux, FreeBSD and Unix. It is used as a telephone exchange, as an IVR (Interactive Voice Response system) or as a connection between telephony based on different techniques and protocols. Asterisk is responsible for the conversion from one protocol to another and the connection between connections based on different protocols. The name comes from the asterisk symbol (*). This symbol is usually used as a wildcard in the computer world. Asterisk is extremely flexible and is therefore also called the Swiss army knife of telephony. License and availability Asterisk is free software released under version 2 of the GPL. Mark Spencer of Digium is the founder of the Asterisk Project and is still a member of the core developer team. Many other programmers and volunteers have already added features and reported bugs. Asterisk was originally written for Linux, but it also works under OpenBSD, FreeBSD, Mac OS X. Since Linux is […]