What is the current state of Web Sockets for Silverlight applications

From what I've read Web Sockets holds more promise than the duplex polling that is currently available to Silverlight developers for receiving server notifications. However I'm not finding much written in 开发者_StackOverflowthe last 10 months, nor am I finding much at all from a Silverlight perspective.

Please don't answer, that Silverlight can open sockets. I know that --- howerver what I don't know is how silverlight can do that with its web server over port 80 in a firewall friendly way -- all of which is why I'm interested in Web Sockets.

---

The underlying Silverlight network stack won't allow port 80 to be connected to. The port restrictions are that the port must be between 4502-4534. See Network Security Access Restrictions in Silverlight.

Microsoft recently release a WebSockets prototype part of which includes a Silverlight WebSocket client. One additional restriction with the Microsoft Silverlight WebSocket prototype implementation is that a clientaccesspolicy.xml file must be served up from port 80 on the server that is being connected to.

The Super Websockets project also contains a Silverlight client somewhere. It will most probably have the same restrictions as the Microsoft implementation.

---

SL4 and 5 do not implement websockets. If browser used to host silverlight plugin supports websockets then you can use browser interop to call websockets api form the silverlight app.

Alternatively a trusted application can connect to any TCP port including port 80.