On Fri, Mar 23, 2012 at 05:50:30AM +0800, Marek Lindner wrote:
Hi,
after numerous infrastructure changes in the past weeks ELP[1] slowly approaches the state in which it can be tested and later merged into the master branch.
Hi Marek
Great to see this work going forward.
Something that Linus and I discussed was using unicast packets as well. We didn't do anything at the time, project deadlines looming etc... It is also a while ago, so maybe i'm remembering this wrong...
The problem with broadcasting the ELP packets is that they are always sent with the most robust coding rate. So ELP gives you an idea how good the 1Mbps broadcast channel is, not how good the unicast channel the automatic rate selection algorithm is using is. I think we discussed mixing in some unicast packets in the forward direction. The ELP packets containing the reports would stay the same, and so function as node detection. But a node could also send out unicast ELP packets to its known neighbours and they would be included into the LQ.
There are obvious drawbacks. More overhead, especially in dense networks. It is also not clear if the measurements would be better. Unicast packets get a number of retries with fast ACKs, where as multicast does not. So multicast might actually give a better measure of the link at 1Mbps.
Do you know if Linus had chance to explore these ideas during his GSOC?
Thanks Andrew