Glossary

• AGI - Asterisk Gateway Interface
• ATA - ATA = Analogue Telephone Adaptor Connects an Analogue Telephone to a VOIP network Usually has an Ethernet jack, and an RJ-11 phone jack. Sometimes referred to as VOIP Gateways, TA (Telephone Adaptor), FXS Adaptor, etc. Some ATAs are locked to a particular provider, and useless with any other. Virtually all ATAs use either the SIP or IAX industry standard protocol. source
• CDR - Call Detail Record. This is the log of a call.
• DID - Direct Inward Dialing; A specially configured phone line from the telephone company that allows for dialing inside a company directly without having to go through an attendant. A DID line cannot be used for outdial operation since there is no dialtone offered.
• E.164 - The international public telecommunication numbering plan. An E.164 number uniquely identifies a public network termination point and typically consists of three fields, CC (country code), NDC (national destination code), and SN (subscriber number), up to 15 digits in total.
• Extension - an additional telephone that operates on the main line. Each extension has its own (internal) number, which often can only be reached via the internal telephone network.
• FXO - The Foreign eXchange Office is the end point of a connection. It is the FXO device that receives a call.
• FXS - A Foreign eXchange Station is the sender of the call to an end-point device.
• Gatekeeper - The central control entity that performs management functions in a Voice and Fax over IP network and for multimedia applications such as video conferencing. Gatekeepers provide intelligence for the network, including address resolution, authorization, and authentication services, the logging of CDRs, and communications with network management systems. Gatekeepers control bandwidth, provide interfaces to existing legacy systems, and monitor the network for engineering purposes as well as for real-time network management and load balancing.
• Gateway - In IP telephony, a network device that converts voice and fax calls, in real time, between the public switched telephone network (PSTN) and an IP network. The primary functions of an IP gateway include voice and fax compression/ decompression, packetization , call routing, and control signaling. Additional features may include interfaces to external controllers, billing systems, and network management systems.
• PBX - A Private Branch eXchange (also called PBX, Private Business eXchange or PABX for Private Automatic Branch eXchange) is a telephone exchange that serves a particular business or office, as opposed to one a common carrier or telephone company operates for many businesses or for the general public. (Source)
• Termination - When used in telephony-context, the line or route reaches an end-user. When connecting from a VoIP telephone to an end-user on the PSTN, somewhere a PBX should make te connection between those two networks and this PBX can terminate the route.
• ToS (Type of Service) - Type of Service is a single-byte field in an IP packet header that specifies the service level required for the packet. It is now called the DS field and can have the following values: Bits 0-2: Precedence Bit 3: 0 = Normal Delay, 1 = Low Delay Bit 4: 0 = Normal Throughput, 1 = High Throughput Bit 5: 0 = Normal Reliability, 1 = High Reliability Bits 6-7: Reserved for Future UseUML
• Trunk - A trunk is the telephony service line that you will be using to make an external call on, e.g. the Telstra telephone line that you have at home is a trunk (or it can be used as a trunk if you wish but not necessarily so). A VOIP service provider (VSP) that you have signed up with is also a trunk. (Source, p.29)