Comtech EF Data CDM-570L - Router Working Mode - Point-To-Multipoint; Figure 16-3. Router Mode, Point-To-Multipoint Diagram

CDM-570/570L Satellite Modem with Optional IP Module Revision 4
Typical IP Module Operation Setups MN/CDM570L.IOM
16.3.3 Router Working Mode – Point-to-MultiPoint
Figure 16-3. Router Mode, Point-to-Multipoint Diagram
“Star Network” Point-to-MultiPoint Configuration - Here, Hub CDM-IP 1 is
transmitting a common 2.048 Mbps link to 2 remote CDM-IPs. In turn, Remote CDM-IP
3 is transmitting a 256 kbps link back to Hub CDM-IP 1. Remote CDM-IP 4 is also
transmitting a 256 kbps link back to the Hub, but it is a separate link to Hub CDM-IP 2.
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. For unicast traffic, it is best
to associate a unique HDLC address for each site in the network. For this case, the Hub
Site is HDLC 0x01, Remote A is HDLC 0x02 and Remote B is 0x03. Each CDM-IP
modem would select the HDLC address associated with its site as a RX HDLC Address,
so both CDM-IP modems at the Hub would have 0x01 as the first RX HDLC Address,
CDM-IP 3 would have 0x02 and CDM-IP 4 would have 0x03.
Hub CDM-IP 1 has static routes defined for both remote CDM-IP subnets with the Next
Hop HDLC address being the HDLC address associated with the remote site. Both
remote CDM-IPs have static routes to the hub with the next Hop being HDLC 0x01. The
Satellite
10/100 BaseT LAN
10.10.0.0 /16
2
0
4
8
k
b
p
s
t
o
a
l
l
R
e
m
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PC
IP 10.10.1.100/16
GW 10.10.1.1
10/100 BaseT LAN
10.20.0.0 /16
Satellite dish
Remote A, CDM-IP 3
(efi0) 10.20.1.1/16
PC
IP 10.20.1.100/16
GW 10.20.1.1
RX
10/100 BaseT LAN
10.30.0.0 /16
Satellite dish
Remote B, CDM-IP 4
(efi0) 10.30.1.1/16
PC
IP 10.30.1.100/16
GW 10.30.1.1
RX
2
5
6
k
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2
TX
TX
Static Routes
IP Dest Next Hop Type
10.10.0.0/16 0x01 ToSat
239.255.30.10 N/A Sat-to-LAN
RX HDLC Addresses - 0x02, 0x10
Static Routes
IP Dest Next Hop Type
10.10.0.0/16 0x01 ToSat
239.255.30.10 N/A Sat-to-LAN
239.255.30.11 N/A Sat-to-LAN
RX HDLC Addresses - 0x03, 0x10, 0x11
Satellite dish
TX
Hub CDM-IP 1
(efi0) 10.10.1.1/16
Static Routes
IP Dest Next Hop Type
10.20.0.0/16 0x02 ToSat
10.30.0.0/16 0x03 ToSat
239.255.30.10 0x10 ToSat
239.255.30.11 0x11 ToSat
RX HDLC Addresses - 0x01
RX
Hub CDM-IP 2 (RX Only)
(efi0) 10.10.1.2/16
RX
Static Routes
IP Dest Next Hop Type
0.0.0.0/0 10.10.1.1 ToEth
RX HDLC Addresses - 0x01
2
5
6
k
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M-
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1
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