19216811.liveEG101
User’s Guide
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TFTP
Trivial File Transfer Protocol
A protocol for file transfers, TFTP is easier to use than
File Transfer Protocol (FTP) but not as capable or
secure.
TKIP
Temporal Key Integrity Protocol (TKIP) provides WPA
with a data encryption function. It ensures that a unique
master key is generated for each packet, supports
message integrity and sequencing rules and supports
re-keying mechanisms.
Triggers
Triggers are used to deal with application protocols that
create separate sessions. Some applications, such as
NetMeeting, open secondary connections during normal
operations, for example, a connection to a server is
established using one port, but data transfers are
performed on a separate connection. A trigger tells the
device to expect these secondary sessions and how to
handle them.
Once you set a trigger, the embedded IP address of
each incoming packet is replaced by the correct host
address so that NAT can translate packets to the correct
destination. You can specify whether you want to carry
out address replacement, and if so, whether to replace
addresses on TCP packets only, UDP packets only, or
both.
Twisted pair
The ordinary copper telephone wiring used by telephone
companies. It contains one or more wire pairs twisted
together to reduce inductance and noise. Each
telephone line uses one pair. In homes, it is most often
installed with two pairs. For Ethernet LANs, a higher
grade called Category 3 (CAT 3) is used for 10BASE-T
networks, and an even higher grade called Category 5
(CAT 5) is used for 100BASE-T networks. See
10BASE-T, 100BASE-T, Ethernet.
Unnumbered interfaces
An unnumbered interface is an IP interface that does not
have a local subnet associated with it. Instead, it uses a
router-id that serves as the source and destination
address of packets sent to and from the router. Unlike
the IP address of a normal interface, the router-id of an
unnumbered interface is allowed to be the same as the
IP address of another interface. For example, the WAN
unnumbered interface of your device uses the same IP
address of the LAN interface (192.168.1.1).
The unnumbered interface is temporary – PPP or DHCP
will assign a ‘real’ IP address automatically.
Upstream
The direction of data transmission from the user to the
Internet.
VC
Virtual Circuit
A connection from your DSL router to your ISP.
VCI
Virtual Circuit Identifier
Together with the Virtual Path Identifier (VPI), the VCI
uniquely identifies a VC. Your ISP will tell you the VCI
for each VC they provide. See VC.
VDSL
Very High Speed Digital Subscriber Line
It provides faster transmission rate and is capable of
supporting high bandwidth applications like IPTV and
bandwidth consumed applications.
VPI
Virtual Path Identifier
Together with the Virtual Circuit Identifier (VCI), the VPI
uniquely identifies a VC. Your ISP will tell you the VPI
for each VC they provide. See VC.