Specifications

HDB3
High-Density Bipolar Order of 3, three-zero maximum coding for E1 lines. Provides a fourth
zero violation for data bytes.
HDLC
High-Level Data Link Control (bit-oriented protocol)
HDSL
High-bit rate Digital Subscriber Line
hlink
A proprietary format for subrate data when using the ADPCM card.
HSU Card
High-Speed Unit Card (one of the data cards for this system).
HMI
Host Management Interface
HOM
HDSL OEM Module
ICMP
Internet Control Message Protocol
IEC
Interexchange Carrier (also called
IXC
)
IMUX
Inverse Multiplexer
IMUX Card
A resource card that gives users access to the ISDN network for bandwidth-on-demand
applications.
inverted a-law
A variation of a-law encoding that provides a higher ones density on E1 lines.