Chapter 8: Glossary
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Splitter
Filter with a low pass (telephone) socket and a high pass socket which is used to
connect to the SHDSL modem. At the local exchange another splitter is connected
to the telephone network (low pass) and the DSLAM (high pass)
Synchronisation and Training
This is the modem initialisation process defined by the G.994.1 (G.hs
handshaking) recommendation. This process, if successful, ends in the state
known as ‘showtime’.
VPI/VCI
The ATM Virtual Path Identifier (VPI) and Virtual Channel Identifier (VCI) uniquely
identify a data path on an ATM link. An ATM switch (or other device incorporating
ATM switching capability like a DSLAM or BAS) can be configured to take data
from one VPI/VCI on an incoming link and map it to another VPI/VCI on an
outgoing link. This configuration defines the route through the ATM switch. Note
that this means that a particular data connection may be given many different
VPI/VCI ‘addresses’ as it passes through the network.
