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The Remote Access Services (RAS) control enables an application to
connect to an Internet Service Provider (ISP) using a standard Dial-Up
Networking connection. Using this control, the application can discover
what dial-up devices are available, what dial-up networking entries,
known as "connectoids", are available on the local system and
allows the program to manage those connections. Existing connections
can be monitored, new connections created and a single control can be
used to manage multiple dial-up connections if the system has more than
one modem. While Windows can be configured to simply autodial a service
provider whenever a network connection is needed, this component gives
your application complete control over the process of connecting to a
service provider, monitoring that connection and then terminating that
connection if needed.
The following properties, methods and events are available for use
by your application:
Initialize
Initialize the control and load the Remote Access Services libraries
for the current process. This method is normally not used if the
control is placed on a form in languages such as Visual Basic.
However, if the control is being created dynamically using a function
similar to CreateObject, then the application must call this method
to initialize the component before setting any properties or calling
any other methods in the control.
Connect
Establish a connection to the dial-up networking server. Once the
connection has been established, the control will authenticate the
session and the local system will have a network connection to the
service provider.
Disconnect
Disconnect from the server and release any resources that have been
allocated for the dial-up networking session. After this method is
called, the session is no longer valid.
Uninitialize
Unload the Remote Access Services libraries and release any resources
that have been allocated for the current process. This is the last
method call that the application should make prior to terminating.
This is only necessary if the application has previously called the
Initialize method.
Connection Properties
The properties of the control are used to set or return
information about the current dial-up networking connection. To load a
dial-up networking connection, called a connectoid or phonebook entry,
use the LoadEntry method. There are a large number of properties,
however the most significant of those properties are as follows:
DeviceName
This property specifies the name of the device that is used to
establish the dial-up networking connection. In most cases this is
the name of an analog modem using a serial communications port,
connected to a standard telephone line. If your application needs to
enumerate the available dial-up networking devices, refer to the
DeviceCount, DeviceEntry and DeviceType properties.
DynamicAddress
This property determines if the dial-up networking connection uses a
dynamically assigned IP address returned by the server, or a specific
IP address configured on the local host. In most cases, this property
should be set to True, unless otherwise specified by your service
provider.
DynamicNameserver
This property determines if the dial-up networking connection uses
dynamically assigned nameservers, used to resolve domain names into
IP addresses. In most cases, this property should be set to True. If
your service provider requires that you explicitly specify the
nameservers to use, then set this property to False and set the
NameServer property array to the address of the nameserver(s) to
use.
InternetAddress
This property returns the IP address assigned to the current dial-up
networking session, if a connection has been established. It can also
be used to explicitly specify an IP address if the DynamicAddress
property is set to False.
NameServer
This is a property array which specifies the IP addresses of the
nameservers that are to be used for the current dial-up networking
session. If a connection has been established, this property array
will return the addresses of those nameservers that have been
assigned to you. If the DynamicNameserver property is set to False,
this property array can also be used to explicitly specify the
nameservers to be used by the dial-up networking connection.
Password
This property specifies the password used to authenticate the dial-up
networking connection.
PhoneEntry
This property specifies the name of the connectoid for the current
dial-up networking connection. If no connection is active and no
connectoid has been loaded, then this property will return an empty
string.
PhoneNumber
This property specifies the telephone number for the dial-up
networking connection. You should also check the value of the
CountryCode property, which will tell your application if area code
dialing rules are being used. If the CountryCode property is set to
zero, then no area code dialing rules are in effect and the telephone
number is dialed as-is. Otherwise you should check the value of the
AreaCode property if you need to determine the area code being used
for the connection.
UserName
This property specifies the username used to authenticate the dial-up
networking connection.
Managing Connectoids
A connectoid contains the information needed to establish a connection,
and is represented as the icon in the Network Connections for the local
system. Connectoids are referenced by name and typically are named
after the service provider, such as "EarthLink" or
"Verizon". In addition to simply connecting to a dial-up
networking server, the control also enables your application to create,
edit and delete these connectoids. Note that in the control
documentation, connectoids are also referred to as "entry names" or
"phonebook entries". The connectoids are
stored as entries in a database files called "phonebooks" and in
most cases, we recommend that you simply use the default phonebook.
CreateEntry
This method displays a dialog box that allows the user to specify the
information needed to create a new connectoid. This is similar to the
dialog that is displayed whenever the user chooses to create a new
Dial-Up Networking connection. Note that if you want to create a
connectoid without showing a dialog to the user, use the SaveEntry
method instead.
DeleteEntry
This method deletes an existing dial-up networking connection.
Exercise caution when using this method; once a connectoid has been
deleted, there is no way to recover it.
LoadEntry
This method loads an existing connectoid, and updates the control's
properties to reflect the connectoid's settings. Changing one or more
of those properties and then calling the SaveEntry method is how you
can modify an existing connectoid.
RenameEntry
This method renames an existing connectoid.
SaveEntry
This method modifies or creates a new connectoid based on the current
properties of the control. If the connectoid already exists, it is
modified, otherwise a new connectoid is created. Unlike the
CreateEntry method, this method will not display any dialogs, so it
is the responsibility of the application to provide a user interface
if needed.
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