TORNADO WEBJET 128
Allied Data Technologies
6
The Function of the Tornado WebJet 128
Computers can exchange information, for example by floppy disk, by connecting two RS232 ports or through a network.
When the Tornado WebJet 128 is used, information is exchanged through the RS232 port and the ISDN network.
In a direct connection between two serial ports, it is only possible to bridge a limited distance (approx. 15 meters). The
ISDN network is used to cross greater distances. It is an existing infrastructure which can be used to establish worldwide
connections. The ISDN network is digital which means data may be sent directly from the serial port by means of a
protocol.
The Tornado WebJet 128 holds a number of standard protocols for exchanging data. In most cases, PPP (Point to Point
Protocol) is used to gain Internet access through an Internet Provider. The V.110 or V.120 protocols are used to contact
BBSs.
Internet Access
There are three common ways to gain Internet access through ISDN:
*PPP or multilink PPP
*V.120 with serial port speed adjustment
*V.110 without serial port speed adjustment
The mode you use is dependent on the access facilities of the Internet Service Provider (ISP) or Point Of Presence (POP)
(see Figure 2).
Figure 2: Access to an On-line Service
Internet Configuration
You can only gain ISDN access to the Internet if you have a contract with an Internet Service Provider (ISP) who works
with ISDN access. You will need the following information from your ISP to configure the Tornado WebJet 128:
*ISDN access number (to be entered into the PC program)
*The protocol used, for instance PPP (command: AT&O7), which has to be configured in the Tornado WebJet 128
*Access protocol (which has to be entered into the PC system software or the Internet software), usually PPP
You may need additional information to configure the Internet access software, like TCP/IP address, user name, password,
etc. For more information, consult the software manual and contact your ISP.
Remote LAN Access
In order to gain remote access to a LAN through ISDN, it is necessary for you to apply the protocol used by the ISDN
router on the LAN. Contact the system administrator.
Data bits, control bit and speed
The RS232 standard describes how serial information is processed (passed on). In a computer, bits are processed
concurrently (parallel). These bits are passed on one by one through the serial port. In order to make sure the receiving
end can interpret these data bits correctly, some extra bits are sent along.
