Quality of Service - Telephony API Programmer's Reference

Custom Search

Quality of Service

As Asynchronous Transfer Mode (ATM) networking emerges into the mainstream of computing, and support for ATM has been added to other parts of the Microsoft® Windows® operating system, TAPI also supports key attributes of establishing calls on ATM facilities. The most important of these from an application perspective is the ability to request, negotiate, renegotiate, and receive indications of Quality of Service (QOS) parameters on inbound and outbound calls.

QOS information in TAPI is exchanged between applications and service providers in FLOWSPEC structures which are defined in Windows Sockets 2.0.

Applications request QOS on outbound calls by setting values in the flowspec fields in the LINECALLPARAMS structure. The service provider will endeavor to provide the specified QOS, and fail the call if it cannot; the application can then adjust its parameters and try the call again. Once a call is established, an application can use the lineSetCallQualityOfService function to request a change in the QOS; a new bit, LINECALLFEATURE_SETQOS, lets applications determine when this function can be called.

The QOS applicable to inbound or active calls can be obtained by using lineGetCallInfo and examining the flowspec fields. A bit in the LINE_CALLINFO message, LINECALLINFOSTATE_QOS, lets applications know when QOS information for a call has been updated.

Support for QOS is not restricted to ATM transports; any service provider can implement QOS features.

Last news from Greatis Software

    Nostalgia .Net     .Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More »

Recommended software for developers

    Ultimate Pack     Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More »

    Form Designer .Net     Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More »

    Print Suite .Net     Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More »

    Gradient Controls .Net     Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More »

    Greatis iGrid     iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More »

All the contacts and projects

Dmitry Vasiliev (just.dmitry)

More Online Helps

Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages

greatis just4fun network