Grandstream Networks 200 User Manual

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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 
 
IP 
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 
octet
s (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.