Nortel DMS-250 - Protocol-User Mode

13-2 ETSI PRI
297-2521-106 Standard 23.01 March 2001
•
protocol conformance—ETSI PRI messages and information elements;
messages formats
Figure 13-1 shows the network mode configuration for ETSI PRI. The
DMS-250 is the network side of the ETSI PRI interface and is interworked
with ITU ISUP IMT interface to provide communication with the public
switched network.
Figure 13-1xxx
ETSI PRI DMS-250 switch configuration—network mode
Public switched network
Customer
PBX
M1
Master
mode
ISN
DAP
RLT
ITU ISUP
Network mode
DMS-250
Switch
ETSI
PRI
ETSI
PRI
X.25
X.25
The ISDN layer 1 and Layer 2 protocols for ETSI PRI are handled solely by
the DTCOi+ peripheral and are generally in compliance with the appropriate
ETSI standard. Layer 3 functionality is handled jointly by the customer
connect and the extended peripheral modules. As part of this feature, the
layer 3 protocol for basic call control on ETSI PRI is supported on the
DMS-250 switch. The implementation of layer 3 is based on ETS 200 102-1
and is generally in compliance with the ETSI standard.
Protocol—user mode
In addition to the network mode functionality of the DMS-250, the user
mode allows the DMS-250 to connect to the public switched telephone
network in the user mode. Figure 13-2 shows this configuration.