Grinch Border Router - routing HTTP traffic

2011/09/29

In my last post devoted to Grinch Border Router I described how to forward pings through the router. However the router wasn’t capable of sending much more than standard size pings. It wasn’t possible to route any IPv6 packet larger than 152 bytes. I blamed it on Zigbit’s limited memory, and decided to get a new module with Atmega128RFA1.

However in the meantime I had some problems with my DSLR and decided to try, and repair it myself. I failed miserably and damaged the power board of the camera, and had to send it to the professionaI support. I had to pay for the new power board, and had no cash for the RFA1 modules, so I decided to work on the Zigbit a little bit more :) . It quickly turned out, that Zigbit has enough memory for everything. I just had to turn off the webserver, and I managed to fit the full 1280-byte buffer for the packets. I also had to correct some bugs:

After these changes the Grinch has become quite usable as a border router. It is possible to access Raven webserver from the PC almost every time. Also large 1232 byte pings are forwarded without problems. The router is still not ready for the deployment, but it’s perfectly ready for testing of wireless sensor networks.

Next thing to do is the automatic discovery of Grinch in the network. For that Router Advertisements are needed. I still haven’t modified this part of Contiki to support multiple interfaces, but it shouldn’t be hard. I also plan to run some long tests of the router to see how stable it is.