Polycom DOC2238A - Manual (Page 100)

Chapter 4 - Hardware Description
4-20
The Functional Modules are described in detail in the following segments.
Net-2/Net-4/Net-8 or T1-CAS Network Interface Module
The Net-2/Net-4/Net-8 Network Interface module provides the interface
between the MGC+ unit and the ISDN network or T1-CAS lines.
Figure 4-10: Net-2/Net-4/Net-8 ISDN/T1-CAS Network Interface Module
The Net-2/Net-4/Net-8 card connects to the I/O-2, I/O-4, and I/O-8 cards
respectively. The I/O-8 card contains connections of up to eight PRI spans, of
either an E1 or T1 line and it can work with both types simultaneously. When
the Net-2/Net-4/Net-8 card is used for T1-CAS lines, only T1 spans are
connected to the I/O card.
Different types of ISDN and T1-CAS Network Interface Modules can be
installed. For more details, see “MGC+ Functional Modules Description” on
page 4-16.
TDM Interface
DPR
COM
Processor
Card
Manager
Front
Panel
LEDs
Watch
Dog
HDLC Interface
PHYI/F FRAMER
TDM I/F
The same type of card can be used to connect ISDN lines or T1-CAS lines.
However, you cannot connect ISDN lines and T1-CAS lines to the same network
card.