xAP Framework v2 hubs
Any PC that runs more than one xAP application needs to run a xAP hub. The hub is required because only one program on a computer is allowed to connect to an IP port and receive data. xAP data is sent over the LAN using UDP packets on port 3639. The job of a xAP hub is to listen for xAP messages on port 3639 and distribute them to all the other xAP programs (clients) running on the computer. Hub functionality is part of the xFx library. Any application developed with xFx can act as a xAP hub if it needs to. xFx Hub applications are simple wrappers for xFx that act as dedicated hubs. There are three versions available, the only difference between them is the way that they present their user interface:
- The xFx Hub Windows service version runs with no user interface in the background. This is the most often used version of the hub. Once it is installed it starts up with all the other background services that a Windows PC runs. Install it and forget it.
- The xFx Hub GUI version runs as a Windows Form application with a graphical display of the clients that the hub is working with and a list of the messages processed. This is useful for developers needing to check out how their applications are interacting with the hub or for interested users who want to see what is happening.
- The xFx Hub Console version is similar to the GUI version but is run from a command line with all output being shown as simple text.
The xFx v2 hubs and operate differently to v1 hubs. The key differences are:
- All UDP packets received are forwarded to hub clients irrespective of whether they are valid xAP messages or not.
- Support for extended UID's is included; hub clients can use xAP v1.2 UID's or extended UID's and these can be mixed on the same computer.
- Increased performance from xFx v2.
- Require Microsoft .Net v2.0.
If you have more than one PC on your network running a v1 hub then you should upgrade them all to v2 hubs at the same time to ensure compatibility.