Perle Systems P840 - Manual (Page 11)

Introduction
11
P840 Router Feature Definitions
Telnet
A Telnet LAN station or another P840 router has the ability to connect to the Operator Interface of any P840 router
supporting the Telnet feature. With the Telnet feature, all of your P840 routers may be managed from a single point.
Once a connection is established all of the menus of the other bridge/router are now available on the bridge/router that
initiated the connection. All menu operation on the initiating bridge/router is suspended during the connection. Entering a
control-C character <^C> at any time during the connection will cause a disconnection, and you will be back to the menu of
the first bridge/router.
To implement the Telnet feature, each bridge/router requires an IP address (see the Internet Set-Up Menu). It is advisable to
assign an IP address to each P840 router in your network that you wish to use to make Telnet connections.
Once a bridge/router has an IP address, any other P840 router may connect to it by entering the IP address in the connection
attempt.
The IP addresses of the other P840 routers must be entered manually each time you wish to make a connection. The IP
address of another bridge/router may be mapped to a name to simplify the connection process. Each P840 router may have a
different set of names for corresponding IP addresses. Refer to the Remote Access Set-Up Menu for more information on
adding names to the bridge/router.
If a bridge/router does not have an IP address, Telnet connections cannot be initiated or received.
If a Telnet connected bridge/router receives a second connection attempt from another bridge/router the connection attempt
will be ignored.
Connecting to a bridge/router while the remote bridge/router menu system is operating with a different terminal setting may
cause unexpected screen errors. Once the connection to the bridge/router has been established, it is recommended that the
operator change the terminal setting to be the same as the initiating device.
When a Telnet connection is made to a bridge/router, ensure that the Telnet session is in character mode, and carriage return
padding (or translation) is set to NULL (or no translation). The extra character sent when carriage return padding is on will
cause some displays to behave erratically.
Link Compression
The P840 router’s optional compression feature multiplies the effective data throughput across wide area links. The exact
amount a given transmission can be compressed is dependent upon the type of data being transferred over the wide area
network. As an example, because of their repetitive make-up, most graphics and database files can easily be compressed by a
ratio of 6:1. In contrast, other types of files (such as binary files), that are not as repetitive, typically yield a compression ratio
of 2:1. It should also be noted that compression ratios are entirely dependent upon the make-up of the specific file — while it
may be possible to compress a given ASCII file far beyond the 6:1 ratio, a different ASCII file may only compress to a ratio of
4:1 or lower.