Lucent Technologies PortMaster, Configuration Manual

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Glossary
Glossary-34 PortMaster Configuration Guide
transit service
In BGP, the function provided by an autonomous system that is in the path of a route but
not the origination or destination. To provide reliable transit service, an autonomous
system must ensure that its BGP and non-BGP routers agree on the interior routes and
exit and entry points for each transit route through the autonomous system. The
PortMaster synchronizes routing information between the BGP and non-BGP routers
within its autonomous system by means of the
lockstep feature. See also lockstep .
Trivial File Transfer Protocol
See TFTP .
two-way
Relating to a port configuration that allows both incoming and outgoing calls.
U
UDP
User Datagram Protocol. A connectionless protocol defined in RFC 768. UDP exchanges
datagrams but does not provide guaranteed delivery.
U interface
The ISDN interface defined as the connection between the network termination 1 device
(NT1) and the telephone company local loop. The U interface standard is set by each
country. The U interface described in PortMaster documentation refers to the U.S.
definition.
UNIX
A multiuser, multitasking operating system originally developed by AT&T that runs on a
wide variety of computer systems.
UNIX-to-UNIX Copy Program
See UUCP .
update message
A message sent between BGP peers to convey network reachability information in two
parts. The first part lists the IP address prefixes and associated netmasks for one or more
routes that the PortMaster is withdrawing from service because it can no longer reach
them. The second part of an update message consists of a single BGP route. See also
route .