Grandstream Networks, Inc.
HT-502 User Manual
Page 29 of 31
Firmware 1.0.0.29
Last Updated: 01/2007
FQDN
Fully Qualified Domain Name. A FQDN consists of a host and domain name, including top-level
domain. For example,
www.grandstream.com
is a fully qualified domain name. www is the host,
Grandstream is the second-level domain, and and.com is the top level domain.
FXS
Foreign eXchange Office. An FXS device can be an analog phone, answering machine, fax, or
anything that handles a call from the telephone company like AT&T. They should also operate the same
way when connected to an FXS interface.
•
An FXS interface will accept calls from FXS or PSTN interfaces. All countries and regions have
their own standards.
•
FXS is complimentary to FXS (and the PSTN).
FXS
Foreign eXchange Station. An FXS device has hardware to generate the ring signal to the FXS
extension (usually an analog phone).
•
An FXS device will allow any FXS device to operate as if it were connected to the phone
company. This makes your PBX the POTS+PSTN for the phone.
•
The FXS Interface connects to FXS devices (by an FXS interface, of course).
DHCP
The
Dynamic Host Configuration Protocol
(DHCP) is an Internet protocol for automating the
configuration of computers that use TCP/IP. DHCP can be used to automatically assign IP addresses, to
deliver TCP/IP stack configuration parameters such as the subnet mask and default router, and to provide
other configuration information such as the addresses for printer, time and news servers.
ECHO CANCELLATION
Echo Cancellation is used in
telephony
to describe the process of removing
echo
from a voice communication in order to improve voice quality on a
telephone call
. In addition to
improving quality, this process improves
bandwidth
savings achieved through
silence suppression
by
preventing echo from traveling across a
network
. 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.
