glo-10 S martSw itch 18 00 4. 0 User G uide , Rev 01
SSAP stands for “source service access point, ” which is the add ress of the link serv ice access
point (LSAP) from which a link protocol data unit (LPDU) originates.
Subsc rib er
is a user of the SmartSwitch 1800 device. Subscriber IDs are the called and calling
addresses used in X.25 call setup.
SVC stands for “switched vir tual circuit,” which is a temporary logic al association between
two subscribers connected to a network, analogous to connection by a dial-up line.
T
TCP stands for “transmission control protocol,” which is the Internet standard transport
layer pr o t ocol.
Throughput Class
(sometimes abbreviated “thruput” class) reflects the line speed in bits per second.
Token Ring
is a MAC (see that entry) technique for data transmission that uses a “ring” configu-
ration of stations, and a “token” that is pas sed around the ring u ntil taken by a statio n,
which inserts a packet, then retransmits the token.
TPAD is an integral (to a SmartSwitch 1800) SNA or BSC PAD connected to a terminal.
Trunk is a physical or logical link between nodes.
Two-wire
is a circuit that uses the same two wires for both inbound and outbound signals.
V
V.35 is a C CITT standard defining a physical and electrical interface that is typically used
by high-speed digital carriers.
Virtual circuit
is an independent logical path between two sub scribers of a packet switching network,
established for the purpose of exchanging data.
VTAM stands for IBM’s “virtual telecommunications access method.”