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Using the MSS
Serial Tunnel
5-7
5.3 Serial Tunnel
Two MSS servers can be connected to emulate a direct serial connection across a LAN or
WAN. Servers connected in this way can pass data only—they will not be able to pass
status signals (DSR/DTR, CTS/RTS, etc.) or preserve timing between characters. The basic
network configuration for this virtual serial line is shown in Figure 5-6.
Figure 5-6: Back-to-Back MSS Connections
5.3.1 TCP Configuration
Assuming the MSS network and serial port parameters have been configured properly, the
Servers would be configured as follows:
Local>> CHANGE DEDICATED TCP 192.168.5.10:3001T
Local>> CHANGE AUTOSTART ENABLED
Local>> CHANGE ACCESS REMOTE
Local>> CHANGE DEDICATED NONE
Local>> CHANGE AUTOSTART DISABLED
Note:
If the Servers are on different IP subnets, configure the default
gateway on each unit with the Change Gateway command.
The above commands create a raw (8-bit clean) TCP connection between the serial ports
of the two MSS’s once the units have been power-cycled. The commands for MSS_A
ensure that it will automatically connect to MSS_B each time it is booted. The commands
for MSS_B ensure that it is always available to accept connections from MSS_A.
5.3.2 UDP Configuration
Local>> CHANGE DEDICATED TCP 192.168.5.10:4096U
Local>> CHANGE AUTOSTART ENABLED
Local>> CHANGE ACCESS DYNAMIC
Serial Device
Serial Device
A
B
Ethernet
192.168.5.2
192.168.5.10