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Panasonic 15000 User Manual

Page 60

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List of terms

Nortel Multiservice Switch 7400/15000/20000

Terminology

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Copyright © 2006, Nortel

Nortel Confidential

hard rerouting

See

connection recovery (page 33)

.

HDB3

See

high-density binary 3 zero maximum encoding (HDB3) (page 60)

.

HDLC

See

high-level data link control (HDLC) (page 61)

HDLC mode

See

frame-cell trunk (page 54)

.

HDLC-transparent data service (HTDS)

A service that transports HDLC-framed data across the network without
interpretation, except that interframe flags are not transmitted. The efficiency
of the transmission is increased by not transmitting flags.

header error control (HEC)

A CRC code found in the last byte of the ATM cell header that is used for
verifying cell integrity.

hello packet

A type of PNNI routing packet that neighboring logical nodes exchange.

Hello protocol

The Hello protocol is a neighbor discovery protocol run over private network-
to-network interface (PNNI) links between lowest level nodes and logical
group nodes (LGNs).

HEP

See

hot equipment protection (HEP) (page 62)

.

HG

See

hunt group (HG) (page 62)

.

hierarchically complete source route

A stack of DTLs that represent a route across a PNNI routing domain. A DTL
is included for each hierarchical level between and including the current level
and the lowest visible level in which the source and destination nodes are
reachable.

high-density binary 3 zero maximum encoding (HDB3)

An encoding technique used to transfer bits over E1 and E3 lines. To ensure
1’s density, HDB3 substitutes a bipolar violation where four or more 0s are to
be sent in a row.