User Manual

Additional Remote Networking Reducing Cost
5-10
5.4.4 IP Header Compression
Each site may be configured to compress the header information on IP (TCP only) packets before they are
forwarded. When a site is created, IP header compression will be enabled by default.
Header compression is most useful for interactive traffic such as Telnet sessions. Compressing the header
information for interactive traffic decreases the delay before data is transferred. In other words, if a key is
pressed during a Telnet session, the time required to echo that character back to the user’s terminal will be
reduced.
For more information on IP header compression, see Header Compression on page 6-8.
5.5 Reducing Cost
5.5.1 Inactivity Logouts
The SCS can be configured to log out a particular site after a certain period of inactivity (referred to as idle
time). To configure an inactivity timeout, the site must be allocated a maximum idle time in seconds using
the Define Site Idle command.
Figure 5-17: Setting Site Idle Time
The site may then be associated with an idle time filter list. When a site receives packets, it compares them
to this list. Packets that "pass" the filter list will reset the idle timer to zero. If no packets pass the list or
traffic is not received within the idle time, the site will be timed out. If an idle time filter is not used, any
packet traffic sent by the site will reset the idle timer.
Note: Incoming packet traffic does not reset the idle timer if there is no idle time filter.
Idle time filter lists enable the SCS to keep a site active for specific types of traffic, disconnecting the site
if this traffic isn’t sent. For example, imagine that a particular site was intended for interactive traffic. Using
an idle filter list, the site could ensure that other traffic (such as email) wouldn’t keep the connection active.
Note: To configure an idle time filter, see Filter Lists on page 5-2.
5.5.2 Restricting Packets with Startup Filters
To prevent unwanted packets from initiating a connection, each site may be associated with a startup filter
list. Packets destined for a remote site are compared to this list; if they do not pass the filter, they are
discarded.
Startup filter lists are only intended to prevent unwanted connections. If a connection is already in place,
the list is ignored. To configure a startup filter, see Filter Lists on page 5-2.
Local>> DEFINE SITE irvine IDLE 600