User Manual

Basic Remote Networking Incoming Connections
4-9
4.4.4.2 Interval Between RIP Updates
When RIP sending is enabled, the SCS sends RIP updates every thirty seconds. This number can be
adjusted; for example, the update interval may be raised so that RIP updates are sent every minute to reduce
network traffic.
To configure the update interval, use the Define Site IP RIP Update command. The interval must be
specified in seconds; intervals between 10 and 255 seconds are permitted.
Figure 4-13: Adjusting RIP Update Intervals
4.4.4.3 Configuring the Metric
Each RIP packet lists known routes and the “cost” associated with each of these routes. Each SCS site may
configure the cost of its interface; all routes learned through the site will be associated with that cost.
When a router determines a route to a particular destination, a route with a lower cost is more likely to be
included in the route. Configuring a higher RIP cost on a particular site makes the interface a less desirable
route to other destinations.
To set a site’s IP RIP metric, use the Define Site IP RIP Metric command.
Figure 4-14: Configuring a Site’s RIP Metric
In the example above, all routes learned through site irvine will be associated with cost 4. The higher the
cost number, the less desirable the route.
Note: If IP RIP sending is disabled on a site, the Update and Metric values will be
ignored.
4.5 Incoming Connections
This section describes how the SCS deals with incoming connections. When a remote device or network
tries to connect, the SCS forms a serial connection using its asynchronous serial lines. A protocol is then
run on this serial connection to allow network packets to be sent.
The SCS supports the use of PPP and SLIP to send network packets.
PPP The Point to Point protocol (PPP) is recommended whenever possible. PPP
enables devices to simultaneously transport IP packets, negotiate certain
options, authenticate users, and use checksums with virtually no performance
loss.
SLIP The Serial Line Internet Protocol (SLIP) is supported primarily for backwards
compatibility with equipment that does not support PPP. SLIP can only
transport IP packets—it does not support negotiation of IP address or other
options, nor does it provide any diagnostic facilities.
Local>> DEFINE SITE irvine IP UPDATE 60
Local>> DEFINE SITE irvine IP RIP METRIC 4