[Xorp-hackers] Some fixes to OLSR (topology.cc)

[Philip Hugg]

On 13/06/2011 4:53 PM, Ben Greear wrote:
> On 06/13/2011 01:01 PM, Philip Hugg wrote:
>> Hello Ben /all
>>
>> I have attached the modified file 'topology.cc' that contains the
>> changes I've made
>> in the attempt to make OLSR more stable. Unfortunately, there are still
>> problems
>> with the OLSR but at least we are one step closer.
>>
>> Tested Topologies:
>>
>> 1) 9 nodes inline (wireless)
>> n9 - n8 - n7 - n6 - n1 - n2 - n3 - n4 - n5
>>
>>
>> 2) 16 nodes, in 4x4 grid (wireless)
>>
>> n1 - n2 - n3 - n4
>> n5 - n6 - n7 - n8
>> n9 - 10 - 11 - 12
>> 13 - 14 - 15 - 16
>>
>> where, N1 is nei with N2, n5, n6,
>> N2 is nei with n1,n3,n5,n6,n7
>> N3 is nei with N2,n4,n6,n7,n8
>> ...
>> N16 is nei with n11, n12, n15.
>>
>> Topology is stable however a ping from N1 to N16 may not take the
>> shortest path
>> (n1-n6-n11-n16) which is 3 hops. Instead, it may follow path from
>> N1-N2-N7-N12-N16 (4-hops?).
>> When I re-issue the ping many times, it may take a different paths.
>
> I'm not sure how OLSR is supposed to work exactly, but that does
> sound buggy.  Could you open a bug with that test case and results?
>
>>
>> 3) Mobility test: 9 nodes inline (as above).
>> When moving N9 from N8 to N7 until we get
>>
>> N9
>> |
>> N8 - N7 - N6 - N1 ...
>>
>> In this case, OLSR asserts.
>
> Can you open a bug with the test case and assert message?  Might help the
> next person to attempt this...
>
>> These are some of the scenarios I used to find the bugs. However, I was
>> pulled off
>> this work and assigned something else. I just thought I would contribute
>> my findings
>> if anyone want to continue.
>
> Thanks for the patch.
>
> But, any chance you could generate a unified patch, ie: diff -u
> or something like that?
>
> That's a lot easier for me to read.
>
> If you don't have time to open these bugs or generate a new diff,
> let me know and I'll take care of it.
>
> Thanks,
> Ben
>
I've included file 'topology.cc.patch'. Generated by
'diff -uEw modified  original > topology.cc.patch'.
Is this OK?

I will issue a bug report for the above.

Phil.

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