Nortel Passport 4400, Using Manual, Page: 136 / 144

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T1
A North American standard for digital voice and data communications
transmitted at the rate of 1.544 Mbps. A Full T1 line can handle twenty-four
64KBPS digital channels for voice or data calls.
TCP
Transmission Control Protocol. A connection-oriented transport-layer
protocol that provides reliable, robust, and adaptable data transfer between
end-system upper-layer protocols (ULP). TCP assumes that simple,
potentially unreliable, datagram services are available from lower-level
protocols. TCP is defined in RFC793.
Telnet
A terminal access protocol for accessing remote devices over an IP-based
network. The protocol provides support for various type of terminals, and is
typically found in IP- or UNIX-based environments.
Transparent CCS
Common channel signaling, passed transparently through the digital voice
module. See also CCS.
Transparent Data Service
A service offered on the Passport that allows the user to send HDLC or SDLC
data across the network without interpretation. See also HDLC Transparent
Data Service (HTDS), and Synchronous Data Link Control (SDLC).
tunneling
A protocol encapsulation process that embeds propriety protocols, such as
PANL, into a carrier protocol, such as Frame Relay.
UAVM
Universal Analog Voice Module. An optional module for the Passport 4400,
the UAVM has two slots into which can be inserted three types voice interface
modules: E & M, FXO, or FXS.
UNI
User to Network Interface. This frame relay service is provided through a
standard interface between the user device and the network, called the
user-to-network interface.