[Olsr-dev] mDNS plugin new features ready for push

Hans-Christoph Steiner (spam-protected)
Tue Jul 31 16:31:33 CEST 2012


I understand how multicast works on the mesh (or doesn't ;), what I'm trying to understand is the design goals of the multicast plugins.

It sounds like the BMF plugin listens for multicast packets, then forwards them via the OLSR infrastructure to cover the whole mesh.  I'm guessing that the goal is to have multicast cover the whole mesh, for use with things like mDNS service advertisement and discovery.

The mDNS plugin that Saverio is talking about seems to be for networks where the mesh is used purely as a backbone, since its goal seems to be forwarding multicast to mesh-attached infrastructure mode networks.  Is that a correct assumption?

For Commotion, the goal is to have both mesh backbones and mesh nodes for end user networking.  It seems that to enable multicast on such a network would require the use of both the mDNS plugin and the BMF plugin.

.hc

On Jul 28, 2012, at 10:25 PM, Jeremy Lakeman wrote:

> Multicast traffic assumes that all devices on a subnet can hear each
> other. A multicast router only repeats multicast traffic on interfaces
> that it didn't arrive on. This is an assumption that obviously doesn't
> work on a layer 3 routed mesh network.
> 
> Fixing multicast properly would involve a kernel patch to allow all
> multicast traffic to be forwarded across the mesh in olsr broadcast
> messages.
> 
> 
> On Sun, Jul 29, 2012 at 1:04 AM, Hans-Christoph Steiner
> <(spam-protected)> wrote:
>> 
>> I get the general idea of why you'd want mDNS on the mesh, I don't understand why this plugin wouldn't also work only with mesh nodes.  It seems to me that this plugin is only for relaying mDNS messages that originate from a infrastructure mode network associated to a mesh via HNA.
>> 
>> Is the idea that this plugin will work in conjunction with another plugin to provide mDNS for all situations?  Or is there a reason why you're specifically avoiding letting mesh nodes send mDNS?
>> 
>> .hc
>> 
>> On Jul 23, 2012, at 7:02 AM, ZioPRoTo (Saverio Proto) wrote:
>> 
>>> There is a paper where I explain everything:
>>> http://zioproto.ninux.org/download/publications/mdns-plugin-paper.pdf
>>> 
>>> ciao,
>>> 
>>> Saverio
>>> 
>>> 
>>> 2012/7/23 Hans-Christoph Steiner <(spam-protected)>:
>>>> 
>>>> Sounds very specific, what use case do you have in mind for it?  How does this compare to the BMF plugin/
>>>> 
>>>> .hc
>>>> 
>>>> On Jul 22, 2012, at 2:34 PM, ZioPRoTo (Saverio Proto) wrote:
>>>> 
>>>>> Hello Hans,
>>>>> 
>>>>> please note that the mDNS plugin let's the hosts on not-olsr networks
>>>>> attached to the OLSR router (and usually announced via HNA entries) to
>>>>> use mDNS across the mesh. Read carefully the README in the mdns folder
>>>>> to discover more.
>>>>> 
>>>>> it is a different thing about the mDNS messages generated from the
>>>>> OLSR router. The plugin is not able to intercept those messages.
>>>>> If you dig in the archives of the mailing list you will find an
>>>>> attempt to do this, configuring the local avahi-demon to use the
>>>>> loopback interface. However it did not work out back at the time.
>>>>> 
>>>>> In other words, if your Android Cell-Phone is also the OLSR router, it
>>>>> will not work to use mDNS.
>>>>> If your Adroid phone is connected to a AP, that is further connected
>>>>> to a OLSR backbone, then mDNS is what you need :)
>>>>> 
>>>>> ciao,
>>>>> 
>>>>> Saverio
>>>>> 
>>>>> 
>>>>> 2012/7/22 Hans-Christoph Steiner <(spam-protected)>:
>>>>>> 
>>>>>> I don't know enough about that code to comment on it, but I'm happy to
>>>>>> see mDNS support in development!  We plan on including it in own Android
>>>>>> client so that people can do XMPP-Bonjour chat across a mesh.
>>>>>> 
>>>>>> .hc
>>>>>> 
>>>>>> On 07/22/2012 10:44 AM, ZioPRoTo (Saverio Proto) wrote:
>>>>>>> Hello,
>>>>>>> 
>>>>>>> my student successfully finished the GSoC mid-term with just a few
>>>>>>> days of delay on his schedule.
>>>>>>> 
>>>>>>> please look at this work on mDNS plugin:
>>>>>>> https://github.com/zioproto/olsrd-gsoc2012/commits/mDNS-plugin-GSOC
>>>>>>> 
>>>>>>> it looks stable to us, but the more eyeballs the better
>>>>>>> 
>>>>>>> we would like to push it into stable before the 0.6.4 release.
>>>>>>> 
>>>>>>> if there are not negative feedback I will push it in a few days after
>>>>>>> we finish a more extensive testing.
>>>>>>> 
>>>>>>> ciao :)
>>>>>>> 
>>>>>>> Saverio
>>>>>>> 
>>>>>>> PS we are now moving on more work on the metrics that has nothing to
>>>>>>> do with the mDNS plugin.
>>>>>>> 
>>>>>> 
>>>>>> --
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>>>> 
>> 
>> 
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