Why is the web-Server on the PCD is accessible over two different socket ports?

FAQ #100900

 

If http-direct is used, then the Web-Server on the PCD3 and PCD2.M5 CPU’s is accessible over two different socket ports. The default ports are socket port 80 and 81.

It's possible to change the port number with the use the Device Configurator of PG5 2.0 (SP1 or later). To change the port number see the FAQ 101464.

Working principle
The use of two ports allows the user to make a prioritization of the web-requests.
If for example there are 4 devices (A, B, C and D) which do access the S-Web server of the PCD then the user could force the device A, B and C to access the port 80 of the PCD and the device D does access the port 81 of the PCD.
In such a case the requests of the devices A, B and C are queued in the Web-Server socket queue 80 and the request of the device D is queued in the Web-Server socket queue 81. The web server on the PCD does treat both ports evenly.

In the example above the requests of the device D are treated about every 3rd cycle. The requests of the device A, B or C are treated about every 7th cycle.