User Manual

Additional Remote Networking Using the SCS Without Dialup Modems
5-14
Note: ACCM is discussed in detail in Character Escaping on page 7-2
5.6.1.3 Synchronous Leased Lines
The SCS supports asynchronous serial connections. Many leased lines are synchronous. Devices which
convert between synchronous and asynchronous serial signals exist, but they may result in some
performance loss. The current SCS units are not always the best solution for synchronous leased line
applications.
5.6.1.4 Analog Leased Lines
To use an SCS with analog leased lines, the modems on each end of the connection must support leased line
mode and should use asynchronous serial communication.
Note: See your modem’s documentation to configure the modem for leased line mode.
5.6.2 Configuring the Unit for Modemless Connections
The SCS should initiate the connection at boot time and should not time out the connection.
The following configuration is recommended:
◆ Idle timeouts are disabled.
◆ RTS/CTS flow control is used between the SCS and the communications equipment.
◆ If RTS/CTS flow control is not supported, XON/XOFF flow control may be used in conjunction with
PPP. If flow control cannot be used, use PPP and monitor the port for checksum errors which may be
the result of disabled flow control.
◆ The port is dedicated to PPP or SLIP.
◆ PPP or SLIP starts automatically.
◆ The port is configured to support incoming and outgoing connections.
◆ Modem control is disabled
In the following examples (both SLIP and PPP), the SCS has an IP address of 192.0.1.1, and must connect
to another router with IP address 192.99.99.99.
5.6.2.1 PPP
Figure 5-21 displays the command required if PPP is used. Both sides of the leased line should be
configured using these commands.
Figure 5-21: SCS Configuration Without Modems: PPP
Local>> DEFINE IP IPADDRESS 192.0.1.1
Local>> DEFINE PORT 2 ACCESS DYNAMIC
Local>> DEFINE PORT 2 SPEED 19200
Local>> DEFINE PORT 2 FLOW CONTROL CTS
Local>> DEFINE PORT 2 AUTOSTART ENABLED
Local>> DEFINE SITE port2 IDLE 0