MobiLink IP
GLOSSARY – Acronyms and explanations
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SMS
-
Acronym
for
Short Message Service
; means the transmission of short text
messages to and from cellular phones. The messages must be text only (no images or
graphics) and not longer than 160 alpha-numeric characters. Operators of Mobile Phone
Networks use a spare data channel to send SMS messages. You may send SMS messages
to another mobile subscriber, the mobile operator can send you phone settings over-the-air
or commercial companies may send dedicated content to your mobile terminal. The
embedded firmware allows MobiLinkIP to send and receive SMS (via mobile network) from
the computer connected to it.
SIP
– Acronym for
Session Initiation Protocol
- a protocol proposed standard for initiating,
modifying, and terminating an interactive user session that involves multimedia elements
such as video, voice, instant messaging, online games, and virtual reality. It is one of the
leading signaling protocols for Voice over IP, along with H.323. MobiLinkIP is used for VoIP
calls that use the SIP protocol.
SIP clients traditionally use TCP and UDP port 5060 to connect to SIP servers and other SIP
endpoints. SIP is primarily used in setting up and tearing down voice or video calls. However,
it can be used in any application where session initiation is a requirement. These include
Event Subscription and Notification, Terminal mobility and so on. There are a large number
of SIP-related RFCs that define behavior for such applications. All voice/video
communications are done over separate transport protocols, typically RTP.
TCP/IP
– Acronym for Transmission Control Protocol / Internet Protocol. It was established
by the Defense Department of the USA for communications between computers. It has been
at first incorporated in UNIX operating system but has become the de facto standard for data
transmission via networks, including for Internet.
Currently TCP/IP is the basic communication language or protocol of the Internet, but it can
also be used as a communications protocol in private network. TCP/IP uses the client/server
model of communication in which a computer user (a client) requests and is provided a
service (such as sending a Web page) by another computer (a server) in the network.
TCP/IP is a two-layer program. The higher layer, Transmission Control Protocol, manages
the assembling of a message or file into smaller packets that are transmitted over the
Internet and received by a TCP layer that reassembles the packets into the original
message. The lower layer, Internet Protocol, handles the address part of each packet so that
it gets to the right destination. For details see the definitions of those protocols that Access -
LAN supports.
TCP
– Acronym for Transmission Control Protocol. In TCP/IP, the TCP part is the one that
takes care of keeping track of the individual units of data (packets) that a message was
divided into for efficient routing through the Internet. TCP is known as a connection-oriented
protocol, which means that a connection is established and maintained until the message or
messages to be exchanged by the application programs at each end have been exchanged.
TCP is responsible for ensuring that a message is divided into the packets that IP manages
and for reassembling the packets back into the complete message at the other end.
At the destination, TCP reassembles the individual packets and waits until they have all
arrived to forward them to you as a single file. It also checks the received packets. TCP acts
at the transport level (level 4) of the ISO/OSI model. See also ISO/OSI model, packet,
TCP/IP.
TDM
– Acronym for
Time Division Multiplexing
- is a type of digital multiplexing in which
two or more apparently simultaneous channels are derived from a given frequency spectrum
by interleaving pulses representing bits from different channels. In some TDM systems,
successive pulses represent bits from successive channels. In other systems different
channels take turns using the channels for a group of successive pulse-times (a so-called
"time slot"), such as voice channels in E1/T1 landline systems or wireless GSM systems.
What distinguishes coarse time-division multiplexing from packet switching is that the time-
slots are pre-allocated to the channels, rather than arbitrated on a per-time slot basis. Since
it interfaces between VoIP and GSM networks, MobiLinkIP also performs conversion
between TDM and packet-switching!
