Westermo ID-90 - Manual (Page 115)

115 6607-2204
FSK
Frequency Shift Keying. Used in the lowest data rate standards.
Handshaking
Confirmations and status signals sent between communicating devices in order to check
the data stream. There are two general types, hardware (RTS/CTS) and software
(XON/XOFF). In hardware handshaking the RS-232/V.24 status lines are used to control
data flow, whereas with the software method characters are transmitted to control the data.
Hayes commands
A set of commands for controlling ISDN Terminal adapters and PTT modems. Often
refered to as the AT command set. Most adapters/modems support these commands
however there are many variations between manufactures.
HDLC
High level Data Link Control.
HLA
High Layer Attribute.
HLC
High Layer Compatibility.
I.430
Basic user-network interface – Layer 1 specification.
IA5
International Alphabet No. 5.
IIFC
Inhibition of Incoming Forwarded Calls.
in-band command
An In-Band Command is a two or multiple character sequence, consisting of a data link
escape Character followed by a command character. If the command character is followed
by additional characters as defined in the command definition, this is an extended com-
mand; otherwise, it is a short command. Except for the escape character, all short or
extended command characters are limited to the range of 20h to 7Eh and A0h to FEh.
ISDN
Integrated Services Digital Network.
IWU
InterWorking Unit, adapter working like a gateway between two networks.
LAPD
Link Access Protocol on the D-channel. LAPD provides the interface between an
ISDN device and the network termination equipment. LAPD performs functions such
as addressing data frames, maintaining their order, error-checking, and flow control.
It is a serial, synchronous, full-duplex protocol.