Appendix C: Glossary and Acronyms
of fixed-line analog telephone systems, the PSTN is now almost entirely
digital, and now includes mobile as well as fixed telephones.
PPP
point-to-point protocol
Type of communications link that connects a single device to another
single device, such as a remote terminal to a host computer.
PSTN
public switched telephone network
A communications network which uses telephones to establish
connections between two points. Also referred to as the dial network.
QoS
quality of service
A measure of telephone service, as specified by the Public Service
Commission.
RJ11
A six-pin jack typically used for connecting telephones, modems, and fax
machines in residential and business settings to PBX or the local
telephone CO.
SIP
Session Initiation Protocol
An IETF standard for setting up sessions between one or more clients. It
is currently the leading signaling protocol for Voice over IP, gradually
replacing H.323.
Digium, Inc.
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