Specifications

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Catalyst 4224 Access Gateway Switch Software Configuration Guide
OL-2031-02
Chapter 1 Product Overview
Application Notes
• DSP subsystem—Interfaces to the TDM subsystem and CPU subsystem for
converting voice streams to IP packets
• Power subsystem—Provides power to the Catalyst 4224 and inline power to
the IP phones that connect to the 10/100 Ethernet ports
From a logical view, the Catalyst 4224 looks like a router that connects an
Ethernet switch and a TDM switch in one system.
Figure 1-2 shows a logical view of the Catalyst 4224.
Figure 1-2 Logical View of Catalyst 4224
DSP Allocation
The Catalyst 4224 has six digital signal processors (DSPs) installed on the
motherboard. The DSPs convert voice signals into data packets and data packets
into voice signals. The DSPs on the Catalyst 4224 do not perform transcoding and
hardware conferencing. These services are performed at the central site by
Cisco CallManager. The DSPs only support VoIP. They do not support Voice
over Frame Relay (VoFR) and Voice over ATM (VoATM). The DSPs are not
field upgradeable.
IP
IP
WAN
PSTN
Fax
Printer
POTS
TDM
Router
Switch
PC
IP phone
58705