User Manual

Basic Remote Networking Incoming Connections
4-11
4.5.1.2 Starting PPP or SLIP Using Automatic Protocol Detection
You can configure an SCS port to automatically detect a PPP or SLIP packet and, if PPP or SLIP is enabled
on the port, run the appropriate protocol when the packet is received. This eliminates the need for callers to
explicitly start PPP or SLIP.
Enable the PPP autodetection feature with the Define Ports PPPdetect command. This starts PPP with a
temporary copy of the default site. To enable SLIP autodetection, use Set/Define Ports SLIPdetect.
Figure 4-16: Enabling Automatic Protocol Detection
To run a custom site, enable PPP authentication on the port (see Chapter 11, Security, for more information
on PPP authentication). If the remote device sends a valid username and password, and the username
matches a site name, that site will start running on the port. All further configuration of the connection will
be from this new site.
Be aware that in some cases automatic protocol detection should be disabled for security purposes. For more
information, see Automatic Protocol Detection on page 8-4.
4.5.1.3 Starting PPP or SLIP on a Dedicated Port
You can dedicate an SCS serial port so it automatically runs PPP or SLIP when that port is started. No other
protocol can be run on the port; it will continue to run PPP or SLIP until the port is logged out. Whenever
the port receives a character, it starts up a temporary copy of the default site using the appropriate link layer.
A dedicated port cannot be used for character mode connections and the Local> prompt cannot be reached.
To dedicate a port to PPP or SLIP, use the following command:
Figure 4-17: Dedicating a Port to PPP/SLIP
Once PPP or SLIP is running, the behavior of a dedicated port is the same as a port with automatic protocol
detection enabled. A dedicated port also has the same security issues as a port with automatic protocol
detection enabled, so you should setup some form of PPP authentication if you wish to avoid potential
abuses. Dedicated ports only provide access to the temporary site; if you wish to use a custom site, you
should instead enter the Set PPP/Set SLIP commands at the Local> prompt.
When a port is dedicated, the local prompt cannot be accessed, therefore, commands can’t be entered to
disable the Dedicated characteristic. Take caution when dedicating ports; if you’re going to dedicate all SCS
ports, be sure that you have another way to log into the server (such as a Telnet login).
Note: If you cannot log into the SCS, you’ll need to restore the server to its factory
default settings. See Initialize Server on page 12-115.
4.5.2 Incoming Connection Sequence
The following steps detail the events that occur when the SCS receives an incoming call.
Local>> DEFINE PORT 2 PPPDETECT ENABLED
Local>> DEFINE PORT 3 SLIPDETECT ENABLED
Local>> DEFINE PORT 2 PPP DEDICATED
Local>> DEFINE PORT 3 SLIP DEDICATED