Amtelco infinity series - Signaling Protocols; DSP Functions; The H.110 Bus

Introduction • 1-3 •
The H.110 Basic Rate ISDN Board
Each port provides two independent B1 channels which operate at 64 kbps.
These channels can be switched to the H.110 bus, to each other, or to one
of the DSP resources. In addition, there is a 16 kbps D channel which is
used for signaling.
1.1.2 Signaling Protocols
ISDN uses the LAPD protocol on the D channel for call control. The
Layer 2 protocol defines the mechanism used for the exchange of messages
between terminal equipment and the network termination. The board
manages the details of this protocol while providing commands to control
aspects such as TEI (Terminal Endpoint Identifier) address management.
Call control is handled by the exchange of Layer 3 messages as defined by
the Q.931 standard. The H.110 BRI Board allows the application to
directly read and write the raw binary information field of these messages.
Optionally, a higher level interface is provided that masks some of the
details of these messages, making for a simplified applications interface.
This is done through the use of “D” messages.
1.1.3 DSP Functions
The H.110 BRI ISDN Board is equipped with DSP’s that performs a
variety of functions. DTMF and Energy detectors are available for each B
channel. DTMF generators are available for each B channel for signaling
purposes. Call Progress tones are also available, with dial-tone, busy,
reorder, and audible ringback being provided as well as silence and a 1004
Hz. calibration tone. Additionally, 64 channels of voice record and 64
channels of voice playback are available.
1.1.4 The H.110 Bus
The H.110 bus is a digital bus for transporting PCM (Pulse Code
Modulation) signals between telephony boards. It was created by the
ECTF to provide a common bus structure for future development that