Product specifications

CDD-562L/564 Demodulator with IP Module Revision 1
IP Module Ethernet Interface Overview MN/CDD564L.IOM
6–11
Figure 6-4 shows a “Star Network” Point-to-MultiPoint Configuration where the Hub
CDM-IP modem is transmitting a common STDMA carrier to three remote sites with CDM-IP
modems. In turn, the Remote CDM-IP is transmitting a link back to the Hub that is received by
the CDD-564 (70/140 MHz) or CDD-564L (L-Band) Satellite Quad Demodulator.
Figure 6-4. (CDD-564/564L) Point-to-MultiPoint Router Working Mode Diagram
Since this is a Point-to-MultiPoint configuration, HDLC addressing is used so that the traffic
not intended for a particular destination can be filtered (Small or Large HDLC Mode). For
unicast traffic, it is best to associate a unique HDLC address for each site in the network; in this
case, the Hub Site is HDLC 0x01; Remote A is HDLC 0x02; Remote B is 0x03; and
(CDD-564/564L) Remote C is 0x04.
Each CDM-IP modem would select the HDLC address associated with its site as an Rx HDLC
Address, so both CDM-IP modem and the CDD-564L at the Hub would have 0x01 as the first
RX HDLC Address. Remote A CDM-IP would have 0x02, and B would have 0x03, and
(CDD-564/564L) C would have 0x04.
The remote CDM-IP modems only need a single default route to is directed to the Hub HDLC,
0x01. All of the traffic is managed by the static route entries in the hub CDM-IP and
demodulator. The demodulator has a default route to the router for Internet access. It also has
specific routes for the remote networks which are directed to the Hub CDM-IP. The Hub CDM-IP
also has specific routes for the remote networks with the HDLC address associated with each site.