From Forum Nokia Wiki

Note!
This API is not part of the public SDK. It can be found in the SDK API Plug-in.

Purpose

The main purpose of phone client dial API is to make a call which will be aware of the native phone application settings. It has been observed that when using the CTelephony class to make voice calls, the phone settings like setting “send my callerID” to “no” are not reflected in the call which is made, where as the calls made from phone client dial API will be aware of these phone settings.

Use cases

How to make a voice call using Phone client dial API?

To dial a string with pause characters

Example code

aNumber is a string containing the number including DTMF codes

The API needs resources loaded into CONE environment...

Nokia have not made the resource file API for this module public so you will need to roll your own

_LIT(KPhoneClientResourceFile, "z:\\resource\\PhoneClient.rsc");
TFileName resFile(KPhoneClientResourceFile);
BaflUtils::NearestLanguageFile(CCoeEnv::Static()->FsSession(), resFile);
TInt offset = CCoeEnv::Static()->AddResourceFileL(resFile);
TPhCltTelephoneNumber phoneNumber(aNumber);

As nokia have not made the API to remove invalid characters public you will need to roll your own code to remove the invalid characters

// Now set the fields
CPhCltDialer* dialer = CPhCltDialer::NewL();
TPhCltExtPhoneDialData& dialData = dialer->DialData();
dialData.SetTelephoneNumber(phoneNumber);
dialData.SetSendKeyPressed(EFalse);
dialData.SetContactId(KPhCltNoContact);
dialData.SetWindowGroup(KPhCltGoToIdle);
dialer->ExecuteLD();

// Now remove the resource file lock - NB could leak as noted above
CCoeEnv::Static()->DeleteResourceFile(offset);

Where to get the header files and libraries

Partnering API SDK

VOIP Example

Emergency call exmaple

File:CUSSD.zip

Capabilities

At least:
-Network Control  (Currently Manufacturer set!!!!)
-Network Services
-Read Device Data
-Read User Data
-Write Device Data
-Write User Data
-maybe more...