3Com 3C892 - OfficeConnect ISDN Lan Modem Router User Manual page 122

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LOSSARY
Primary Rate Interface. A PRI line is one of two access methods to the ISDN; BRI is
PRI
the other. In North America, each PRI consists of twenty-three 64 Kbps B channels
and one 64 Kbps D channel.
A router is a device that links networks.
router
Service Profile Identifier. If required, this number is supplied to you by the
SPID
telephone company. Typically, if your ISDN line has only one telephone number, a
SPID is not required.
Transmission Control Protocol/Internet Protocol. TCP/IP is a standardized
TCP/IP
communications protocol which allows different types of devices to communicate
with each other over LANs and WANs.
TollMizer (also referred to as Switched 56 Permissive or Data Over Voice) makes a
TollMizer
56 Kbps data call over a voice circuit, allowing you to save the typical cost
difference between a voice and data call. Note that the destination you are calling
must also support this feature.
User Datagram Protocol. A connectionless protocol within TCP/IP that converts
UDP
application-generated data messages into packets that can be sent via IP. UDP
does not check for transmission errors therefore it does not perform
retransmission. Reliability is dependent upon the application. Note that because it
does not perform checking, UDP is more efficient than TCP. UDP is commonly used
for Internet games.
A virtual private network is a secure, private data network that is established over
VPN
the Internet resulting in significant cost savings from using local, toll free access
numbers. Also, because the existing Internet backbone is used, there is less
investment needed in private network infrastructure. See also PPTP.