56
8.4.9.3.3 Typical user setup behaviour
A typical user of EPOC will perform the following setup tasks:
• when first installing software that uses dial-up network, the user will specify a modem
and an ISP; also, the user will check that the default dial settings (home, office and
mobile) are appropriate
• when making a connection, the user will select between home, office and mobile: this is
all that is needed to use dial-up networking from any mobile phone, and from a fixed
home and office
• if travelling abroad and using a “home” type connection to the public phone network
(when no prefix is required before dialling out to the ISP) then the user must use the
Dialling icon on the Control Panel to set up a new location, such as “Home, Korea” and
enter the country from there
• similar changes must be made for other types of location when travelling
Thus, EPOC has been designed to minimise the work necessary to maintain dial-up networking
functionality for mobile users.
8.4.9.3.4 Reconnection
If a connection is inadvertently terminated, but a user later wishes to send or receive data over the
connection, they may be asked whether they wish to reconnect. Reconnection always uses the
same settings as the original connection.
8.4.9.4 Dial-up Networking Architecture
We’ve seen that establishing and using an Internet connection from scratch involves many
different EPOC components. We conclude with a graphical overview of the way that they might
interact, showing the following links:
• A component opens a session with the sockets server, ESOCK and tries to connect to a
specific IP address.
• ESOCK dynamically loads up the TCP/IP protocol family.
• IP asks NIFMAN for a route.
• As no connection exists, NIFMAN loads its NETDIAL Agent to set one up.
• Optionally, NETDIAL invokes its dialog server to check with the user that the comms
database settings they had previously written via the control panel are acceptable.
• At this point, the EPOC DIAL module may invoke the World Server to resolve the
phone number for the current location .
• NETDIAL opens a session with the telephony server, ETEL, and asks it to make the call
and connect.
• ETEL looks up the relevant details for the current port, location, ISP, and phone or
modem in the comms database
• ETEL loads the appropriate TSY module.
• The TSY opens a session with the communications server, C32
• The TSY tells C32 and the EPOC kernel to load the correct CSY comms server module
and the appropriate device drivers.
• At last a hardware connection exists. ETEL can talk to the phone or modem and tell it to
dial up the ISP.
• On connection, ETEL loans the port back to NETDIAL, which can now run any scripts
necessary to log on to the Internet.
• The NETDIAL Agent hands control back to NIFMAN, which now activates the PPP
link protocol for any authentication, and to control the remainder of the call.
• When PPP asks for the line to be dropped, NIFMAN returns control to NETDIAL,
which returnes the port to ETEL for termination of the call, and the whole stack now
unwinds.
To Next Page
Loading...