Isdn Protocol; Isdn Overview - 3Com 3032 Configuration Manual

15

ISDN Overview

Configure ISDN
C
ONFIGURING
This chapter contains information on the following topics:
ISDN Overview
Configure ISDN
Display and Debug ISDN
Typical Configuration Example
Fault Diagnosis and Troubleshooting of ISDN
ISDN (Integrated Services Digital Network), developed from telephone integrated
digital network (IDN), provides end-to-end digital connection, so as to support
wide range of services (including voice and non-voice services).
ISDN provides the user with a group of standard multifunctional user-network
interfaces. In ITU-T I.412 recommendations, two types of user-network interfaces
are specified: Basic Rate Interface (BRI) and Primary Rate Interface (PRI). The
bandwidth of BRI is 2B+D, and that of PRI is 30B+D or 23B+D. Here:
B channel is a user channel, used to transmit the voice, data and other user
information with the transmission rate 64kbps.
D channel is a control channel and used to transmit the common channel
signaling, controlling the calls on B channels of the same interface. The rate of
D channel is 64kbit/s (PRI) or 16kbps (BRI).ITU-T Q.921, the data link layer
protocol of D channel, defines the rules by which the information is exchanged
between layer-2 entities on the user-network interface through D channel.
Meanwhile, it supports the access of layer-3 entity. ITU-T Q.931, the network
layer protocol of D channel, provides methods to establish, maintain and
terminate the network connection between communication application
entities.
Figure 55 Protocol stack of ISDN D channel
ISDN configuration includes:
Configure ISDN signaling type
Configure QSIG signaling parameters
ISDN P
Layer 3 Q.931
Layer 2 Q.921 LAPD
Layer 1 BRI
ROTOCOL
QSIG
PRI