Comtech EF Data CDM-IP 300L - Manual (Page 36)

CDM-IP 300L IP-Centric Satellite Modem Rev. 1
CD/CDMIP300L.IOM
8
Satellite
1
0/
1
00
Ba
se
T
L
A
N
10
.10
.0.0
/1
6
2.
04
8
M
bp
s
to
a
ll
R
em
ot
e
C
D
M
-Ip
s
PC
IP 10.10.1.100/16
GW 10.10.1.1
1
0/
1
00
B
a
se
T
L
A
N
10
.20
.0.
0 /1
6
Satellite dish
256 k
bps to
Hub C
DM-IP
1
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
/1
00
Ba
se
T LAN
10
.3
0
.0.
0
/1
6
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
25
6 k
bp
s t
o H
ub
C
D
M-
IP
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
Figure 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
Hub RX only CDM-IP 2 has a default route (ToEth) to Hub CDM-IP 1 because all
outbound traffic will go through CDM-IP 1.