Polycom DOC2237A - Manual (Page 106)

Chapter 4 - Hardware Description
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ATM Network Interface Module
The ATM Network Interface Module provides the interface between the
MGC unit and ATM network. The ATM card may be shipped in two
configurations: ATM-25 Network Interface Module that supports one 25MB
connection using RJ-45 connector and ATM-155 Network Interface Module
that supports one 155MB connection using a fiber optics connector.
The ATM-25 (FVC) Network Interface Module supports up to 10 H.321
endpoints at 2B or 384 Kbps, using First Virtual (FVC) technology.
The ATM-155 (FVC) Network Interface Module supports up to 20 H.321
endpoints at 2B or 384 Kbps, using First Virtual (FVC) technology.
The ATM-25 Network Interface Module is used with the IO-25 card and the
ATM-155 Network Interface Module is used with the IO-155 card.
Figure 4-17 shows the architecture for the ATM Network Interface Module.
The card architecture is identical to both card types.
Figure 4-18: ATM-25 and ATM-155 Network Interface Module
ATM
ATM Hardware
TDM Interface
ISA Interface
Memory
HDLC Interface
Front
Panel
LEDs
Watch
Dog
Card
Manager
ATM-MVIP Card
MVIP