Internet Connectivity daemon (ICd2)
===================================
Responsible for network connectivity in the device.


Description
===========
The central concept for maemo Internet connections is the Internet
Access Point (IAP), which represents a logical Internet (IP) connection
that the user defines. An IAP has a unique name, usually in form of
UUID). Among other things, it defines the radio bearer (e.g. WLAN,
GPRS), and usually also the data transfer speed, username, password,
proxy server, and the corresponding access point in the Internet or the
telephone number of the service provider's modem.

If the ICd receives a request to activate or deactivate an IAP, the ICd
activates the IAP or, if no IAP has been defined as the default, shows a
UI requesting the user to choose one. Depending on the type of the IAP,
the ICd uses the appropriate network type plug-in to activate or
deactivate specific network interface.

The ICd tracks the applications requesting IAPs by recording their D-Bus
base service names. This allows the ICd to detect situations where
processes using an IAP have aborted or crashed.

Automatic connection creation feature. The device tries to connect
automatically to the saved IAPs, and keep connected as long as possible.
With this feature, applications like e-mail and RSS reader are always up
to date. The device is also always ready for online use, for example,
incoming VoIP calls or IM chat.

When the device is not connected, it scans for saved IAPs and tries to
connect automatically, taking into account the value defined by the
search interval configuration parameter. The search interval can be 5,
10, 30 or 60 minutes; all other values are automatically mapped to
"Never". This setup switches off the automatic connection feature. In
this case connections are created only when applications require it.

Because each application keeps its data updated and provides the always-
online feature, the ICd is only responsible for creating connections.

While writing an application making use of the ICd system, keep the
following in mind:
1. The application must always use the existing available connection.
2. If the device is not connected but a connection is required by user
interaction, the application must require connection creation using
LibConIC API.
3. Ensure that the user is aware of updates and can see the time when
the data was last updated.
4. Ensure that the application registers via LibConIC and listens to
signals emitted by the ICd (Connection Created, Lost and Changed), and
react as follows:
 - Connection Created: Use the connection and update all data.
 - Connection Lost: Go to an idle state silently and wait until a new
   connection is created.
 - Connection Changed: Use the new connection.
5. Ensure that automatic data updates run in background and silently:
 - Avoid alarming the user with unnecessary banners or dialogs.
 - Ensure that usernames and passwords are saved so that automatic
   updates can be performed without prompts.
 - During and after updates, ensure that no failures display error
   notifications.
6. The connectivity infrastructure must take care of error situations in
a centralized way.

You can switch off the automatic connection creation feature by using
offline mode. While in this mode, the configuration parameter for
allowing WLAN in offline mode is checked. Depending on the state of this
configuration parameter, WLAN IAPs are either enabled or disabled in the
offline mode. Also other radios like Bluetooth are normally disabled in
the offline mode.


Responsibilities and requirements
=================================
* Controlling that only one Internet connection (one active IAP) can
  exist at any given time.
* Using WLAN or GPRS connection daemon for getting a network device and
  getting the connection authenticated
* Starting IP level services like PPP and DHCP
* Providing statistics about the usage of IAPs to any application