Streaming AV between devices in general uses the UPnP protocol.
In principle there are 3 different devices,
That’s what is making trouble shouting streaming problems complex, it takes 3 to tango.
You don't need UPnP on the router to be on when the devices are in your local network.
In the local network the router act as a switch so it should simply transmit everything unaltered from one device to another.
It is saver to leave UPnP on the router off.
Some devices like the Xbox needs UPnP to go live on the internet.
Receiving streaming content over the internet sometimes requires the router to support multicast. Enable it on your router.
Often you have some devices connected by wire (Ethernet) and others wireless (Wi-Fi).
It might happen that streaming between them don't work because some routers simply don't bridge the two networks correctly.
A simple check is to connect them the same way (all wired or all wireless)
PC
Check the usual suspects, anti virus and firewall.
Vista has UPnP installed by default. If you put media sharing on in WMP, it will activate all necessary services and firewall settings.
Win7 has the media sharing services always on.
The following services must be up and running:
More details
If you want to share files in a monitored folder that is located on another computer (for example, a folder on a network share), the remote folder must have the appropriate Windows access permissions assigned to it and the computer that contains the library you want to share has remote content sharing enabled. You can enable remote content sharing by performing the following procedure on the computer that contains the library you are sharing.
1. |
Click Start, click Run, type regedit, and then click OK. |
2. |
In the registry tree (on the left), expand HKEY_LOCAL_MACHINE, SOFTWARE, Microsoft, MediaPlayer, and then Preferences. |
3. |
Right-click HME, point to New, and then click DWORD Value. |
4. |
Type EnableRemoteContentSharing, and then press ENTER. |
5. |
Right-click EnableRemoteContentSharing, and then click Modify. |
6. |
In the Value data text box, type 1, and then click OK. If you later decide to disable remote content sharing, you can repeat this procedure and change the value to 0. |
Source: Microsoft
Often NAS manufactures thinks they could save a couple of buck by developing their own UPnP implementation. Some are of DIY quality.
Check user forums for UPnP problems (do so before you buy)
Check if they use a certified UPnP server.
Universal Plug-and-Play Tester (UPnPTest) is an experimental tool that lists all the available devices compatible with the Universal Plug-and-Play protocol including routers (IGDs).
When the program starts it first checks the configuration of the required UPnP services and the Windows Firewall and possibly configures them for you (after being prompted). Then it searches for available devices and updates the list as devices are plugged or unplugged.
A tool to watch http(s) traffic.
This can tell you more about the communication between two DLNA devices as
they use http to communicate.
DLNA Best Practices. PacketVideo Corporation (2009).