22
ADSL2+ Router
are written up as RFCs
RFC 1483
Multi-protocol encapsulation over AAL-5. Two encapsulation methods for carrying network
interconnect traffic over ATM AAL-5. The first method allows multiplexing of multiple protocols over
a single ATM virtual circuit. The protocol of a carried PDU is identified by prefixing the PDU by an
IEEE 802.2 Logical Link Control (LLC) header. This method is in the following called "LLC
Encapsulation". The second method does higher-layer protocol multiplexing implicitly by ATM
Virtual Circuits (VCs). It is in the following called "VC Based Multiplexing".
Router
A system responsible for making decisions about which of several paths network (or
Internet) traffic will follow. To do this, it uses a routing protocol to gain information about the
network and algorithms to choose the best route based on several criteria known as
"routing metrics.
Spanning Tree
Spanning-Tree Bridge Protocol (STP). Part of an IEEE standard. A mechanism for detecting
and preventing loops from occurring in a multi-bridged environment. When bridges connect
three or more LAN segments, a loop can occur. Because a bridge forwards all packets that
are not recognized as being local, some packets can circulate for long periods of time,
eventually degrading system performance. This algorithm ensures only one path connects
any pair of stations, selecting one bridge as the 'root' bridge, with the highest priority one as
identifier, from which all paths should radiate.
TELNET
The virtual terminal protocol in the Internet suite of protocols. Allows users of one host to
log into a remote host and act as normal terminal users of that host.
VCI
Virtual Circuit Identifier. Part of the ATM cell header, a VCI is a tag indicating the channel
over which a cell will travel. The VCI of a cell can be changed as it moves between switches
via Signaling.
VPI
Virtual Path Identifier. Part of the ATM cell header, a VPI is a pipe for a number of Virtual
Circuits.
WAN
Wide area network. A data communications network that spans any distance and is usually
provided by a public carrier (such as a telephone company or service provider)
