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t.30
A type of fax transfer protocol and specification defined by the ITU-T over the public switched telephony network. T.30 describes and specifies the communication process, signal format for communication, control signaling, and error correction method of the three types of fax machines over the common telephony network.
t.38
The supplementary protocol of T.30. It is used to encapsulate T.30 signals so that the signals can be transmitted over the IP network. T.38 does not provide the fax state and the IP fax process is maintained by the state machine of T.30.
TDM
Technique in which information from multiple channels can be allocated bandwidth on a single wire based on preassigned time slots. Bandwidth is allocated to each channel regardless of whether the station has data to transmit. Compare with ATDM, FDM, and statistical multiplexing.
tdm switch
A network technology that requires the connection to be set up and retained before two or more users occupy the circuit exclusively. Typically, an exchange is used to set up a physical connection between users. The switching process occurs in the second layer of the open systems interconnection (OSI) model.
Telnet
Standard terminal emulation protocol in the TCP/IP protocol stack. Telnet is used for remote terminal connection, enabling users to log in to remote systems and use resources as if they were connected to a local system. Telnet is defined in RFC 854.
terminal
A device that converts the following from the physical display to the electronic signal or from the electronic signal to the physical display: voice, sound, text, image, table, data and video. A terminal generates and sends signals (such as telecommunications circuit setup or release) that maintain the normal running state of the telecommunications network, and it receives the call signals of telecommunications switch and transmission.
TFTP
See Trivial File Transfer Protocol
three-party service
A service that allows the caller or callee in a conversation to call a third party without ending the current conversation. Then, the caller or original callee can implement a three-party conversation or converse with either of the other two parties at a time.
Three-Way Calling
A service that allows the subscriber to add a third party to an activated two-party call so that all the three parties may communicate in a three-way call. If subscriber A and subscriber B are in conversation and subscriber A (either the calling party or the called party) has registered and activated the 3WC service, subscriber A dials the number of subscriber C and presses the SEND key to call subscriber C. After subscriber A hears the ringing tone or subscriber C answers the call, subscriber A presses the SEND key to invoke the 3WC service. Thus, subscriber A, subscriber B, and subscriber C communicate in a three-way call. After the three subscribers communicate in a three-way call, if either non-controlling subscriber (subscriber B or C) disconnects the call, the other subscriber is re-connected to the controlling subscriber (subscriber A) as a normal two-party call. If the controlling subscriber disconnects the call, the other two parties are released.
TMG
Topology view
A basic component for the human-machine interface. The topology view directly displays the networking of a network as well as the alarm and communication statuses of each network element and subnet. In this manner, the topology view reflects the basic running conditions of the network.
traffic statistics
An activity of measuring, collecting, and making statistics of various data on devices and telecommunications networks. Through the collected data, operators can observe and take statistics of the running status, signaling, users, usages of system resources of the devices or networks, manage the device running, locate problems, monitor and maintain the networks, and plan the networks.
transfer out
To transfer an incoming call to a specified number.
transferring a call
A service that allows a registered user in conversation to call a third-party user by pressing the hookflash and dialing the phone number of the third-party user. Then, this registered user exits from the calls.
transparent transmission
A process during which the signaling protocol or data is not processed in the content but encapsulated in the format for the processing of the next phase.
transparently-transmitted fax
A method of transferring the fax signal in real time over the IP network after the media gateway encodes the fax signal sent by a fax in voice coding mode (G.711) and converts the fax signal to the RTP data packet.
Trivial File Transfer Protocol
A small and simple alternative to FTP for transferring files. TFTP is intended for applications that do not need complex interactions between the client and server. TFTP restricts operations to simple file transfers and does not provide authentication. TFTP is small enough to be contained in ROM to be used for bootstrapping diskless machines.
trunk
Physical communications line between two offices. It transports media signals such as speech, data and video signals.
trunk circuit
An element that constitutes a trunk group. A trunk circuit is a TDM circuit and relates to an E1/T1 timeslot.
trunk group
An element that constitutes a sub-route. The group is formed by a cluster of circuits of the same type under TDM bearer. Generally, trunk circuits of the same office direction and circuit type are identified as a trunk group.
trunk line
A transmission channel between two switching centers or nodes. It is used to connect the exchange to the network.
trunk line selection
Circuit line selection function that is used when the local office originates outgoing trunk calls.
Trunk Media Gateway
The interface between the traditional telephone network and the IP packet network. It converts the PCM signal stream and packet media stream into each other.
TX
It is the transmitting end of the interface that signals pass through.
Parent Topic: Glossary