On Friday 07 August 2009 23:13:46 Yang Su wrote:
- Some updates: I did more thorough testing. It turns out that this patch
does really solve the problem. This method seems not able to completely eliminate all possible forms of looping which happen in the test cases. This result in an special pattern: the rerouting is fast (~15 seconds), then (after 3~ 5 seconds) the network enters the looping state and it normally takes long time to recover. Last time when I did tests, I stop the tests right after I observed the successful rerouting. I didn't look into the cause of this problem yet. Any inputs are welcome.
Can you provide logs from the nodes involved ? You also can send them off-list to avoid sending too big attachments.
- In the following example (also appended in the attachment :) ), if I
understand the current echo cancellation implementation correctly, batman will enter permanent looping between A and B. In this example, A send to F, all the links are perfect and have the same delay. Only exception is link A-E. It is an asymmetric link.
Why do you think it would loop permanently and why do you think it is the fault of the echo cancellation ? Actually, this example should[tm] be pretty easy. Every time the OGM from E or F arrive at A via the asymetric link A will apply a severe asymetric link penalty. All nodes will route via the longer path. Did you try to run this scenario in your testbed ?