Grandstream Networks 200

There are two types of echo of relevance in telephony: acoustic echo and hybrid

echo. Speech compression techniques and digital processing delay often

contribute to echo generation in telephone networks.

H.323

A suite of standards for multimedia conferences on traditional packet-switched

networks.

HTTP

Hyper Text Transfer Protocol; the World Wide Web protocol that performs the

request and retrieve functions of a server

Internet Protocol. A packet-based protocol for delivering data across networks.

IP-PBX

IP-based Private Branch Exchange

IP Telephony

(Internet Protocol telephony, also known as Voice over IP Telephony) A general

term for the technologies that use the Internet Protocol's packet-switched

connections to exchange voice, fax, and other forms of information that have

traditionally been carried over the dedicated circuit-switched connections of the

public switched telephone network (PSTN). The basic steps involved in

originating an IP Telephony call are conversion of the analog voice signal to

digital format and compression/translation of the signal into Internet protocol (IP)

packets for transmission over the Internet or other packet-switched networks; the

process is reversed at the receiving end. The terms IP Telephony and Internet

Telephony are often used to mean the same; however, they are not 100 per cent

interchangeable, since Internet is only a subcase of packet-switched networks. For

users who have free or fixed-price Internet access, IP Telephony software

essentially provides free telephone calls anywhere in the world. However, the

challenge of IP Telephony is maintaining the quality of service expected by

subscribers. Session border controllers resolve this issue by providing quality

assurance comparable to legacy telephone systems.

IVR

IVR is a software application that accepts a combination of voice telephone input

and touch-tone keypad selection and provides appropriate responses in the form

of voice, fax, callback, e-mail and perhaps other media.

MTU

A Maximum Transmission Unit (MTU) is the largest size packet or frame,

specified in octets (eight-bit bytes), that can be sent in a packet- or frame-based

network such as the Internet. The maximum for Ethernet is 1500 byte.