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Grandstream
HandyTone 502 Specifications
Technical
Specification
Glossary
ADSL
- Asymmetric Digital Subscriber Line. Modems attached
to twisted pair copper wiring that transmit from 1.5Mbps
to 9Mbps downstream (to the subscriber) and from 16kbps
to 800kbps upstream, depending on line distance.
ARP - Address Resolution Protocol is a protocol
used by the IP (Internet Protocol), IPv4, to map
IP network addresses to the hardware addresses used by a
data link protocol. The protocol operates below the network
layer as a part of the interface between the OSI network
and OSI link layer. It is used when IPv4 is used over Ethernet.
ATA
- Analogue Telephone Adapter. Enables analogue telephone
to be used in data network for VoIP.
CODEC
- Abbreviation for Coder-Decoder. It is an analog-to-digital
(A/D) and digital-to-analog (D/A) converter for translating
the signals from the outside world to digital, and back
again.
DATAGRAM
- A data packet carrying its own address informaton
so it can be independently routed from its source to the
destination computer.
DNS
- Short for Domain Name Service, an Internet service
that translates domain names into IP addresses.
DSP
- Digital Signal Processor. A specialized CPU used
for digital signal processing. All Grandstream products
have DSP chips inside.
DTMF
- Dual Tone Multi Frequency. The standard tone-pairs
used on telephone terminals for dialing using in-band signalling.
The standards define 16 tone-pairs (0-9, #, * and A-F) although
most terminals support only 12 of them (0-9, * and #).
FXO
- Foreign eXchange Office. An FXO device can be an
analog phone, answering machine, fax, or anything that handles
a call from the telephone company
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 uses additional
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 OBX
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 is an Internet
protocol for automating the configuration of computers that
use TCP/IP. DHCP can be used to automatically assign IP addresses,
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 of a telephone call. In
addition to improving quality, this process improves bandwidth
savings achieved through silence suppression by preventing
echo from travelling 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.
NAT
- Network Address Translation.
PPPoE
- Point-to-Point Protocol over Ethernet is a network
protocol for encapsulating PPP frames in Ethernet frames.
It is used mainly with cable modem and DSL services.
PSTN
- Public Switched Telephone Network. The phone service
we use for every ordinary phone call, or called POTS (Plain
Old Telephone Service), or circuit switched network.
RTCP
- Real-time Transport Control Protocol. With the RTP
it is delivery and packaging of multimedia data, but does
not transport any data itself. It is used periodically to
transmit control packets to participants in a streaming multimedia
session. The primary function of RTCP is to provide feedback
on the quality of service being provided by RTP.
RTP
- Real-time Transport Protocol defines a standardized
packet format for delivering audio and video over the Internet.
SDP
- Session Description Protocol is a format for describing
streaming media initialization parameters.
SIP
- Session Initiation Protocol. SIP is a text-based protocol
suitable for integrated voice-data applications. SIP is designed
for voice transmission and uses fewer resources while it is
considerably less complex than H.323. The Grandstream products
are SIP-based.
STUN - Simple Traversal of UDP over NAT is a network
protocol allowing clients behind NAT to find out its public
address, the type of NAT it is behind and the internet side
port associated by the NAT with a particular local port. This
information is used to set up UDP communication between two
hosts that are both behind NAT routers. It works with non-symmetric
NAT routers.
TCP - Transmission Control Protocol is one of the
core protocols of the Internet protocol suite. Using TCP, applications
on networked hosts can create connections to one another, over
which they can exchange data or packets. The protocol guarantees
reliable and in-order delivery of sender to receiver data.
TFTP
- Trivial File Transfer Protocol, is a very simple
file transfer protocol, with the functionality of a very basic
form of FTP. It uses UDP (port 69) as its transport protocol.
UDP - User Datagram Protocol is one of the core protocols
of the Internet protocol suite. Using UDP, programs on networked
computers can send short messages known as datagrams to one
another. UDP does not provide the reliability and ordering guarantees
that TCP does; datagrams may arrive out of order or go missing
without notice. UDP is faster and more efficient for many lightweight
purposes.
VLAN - A Virtual LAN, is a logically-independent
network. Several VLANs can co-exist on a single physical switch.
VoIP
- Voice over the Internet Protocol. VoIP encomprasses
many protocols. All the protocols do some form of signalling
of call capabilities and transport of voice data from one point
to another. |
