How to create Policy-based QoS on Windows 7 through CLI?

Question

I am trying to add ToS (QoS) support to a SIP client (taken from open-source Linphone) as so:

retval = setsockopt(session->rtp.socket, proto, value_type, (SOCKET_OPTION_VALUE)&tos, sizeof(tos));

But in Windows 7, all my attempts to add ToS failed; it continues to set zeros (as seen in Wireshark). Someone said it’s a “feature” (read bug) in Windows.

I read in this page how to create a QoS policy, so I created one manually by using the GUI:

I tried the following steps:

1. Go to HKLM\System\CurrentControlSet\Services\Tcpip\QoS
2. Create the QoS key if it doesn’t exist
3. Add a REG-SZ parameter named Do not use NLA and give it the value 1
4. Reboot

It works as desired, but now my question is how can I automate the creation of such a policy (e.g., so that it can be done during a program installation)?

[EDIT]

My code is pure C and to use C# source code will be problematic a bit since I use the minGW environment and tools with ./configure && make && make install.

Answer 1

The article Programmatically updating local policy in Windows describes a .NET library that can assist with this problem.

If you do not wish to write a .net program, the simplest solution would be to create a AutoHotkey macro, possibly compiled to an .exe, that will do the GUI manipulations that create that group policy.

If you are using Windows 8 or Server 2012, the configuration of QoS is possible via PowerShell:
Network Quality of Service (QoS) Cmdlets in Windows PowerShell.