Subject: [manet] OLSR MID messages

From: manet user <[email-masked]>
Date: Fri, 12 Mar 2004 08:05:21 -0800 (PST)

Hi,
 
I am styduying the OLSR implementations and RFC. I couldn't understand from the RFC, how does the communication starts in a network. 
 
My understanding is: 
- every node that has multiple interfaces sends out MID messages (full boradcast), 
- each node also sends out Hello message (with no addresses in Data part)
- nodes receving these packets create various sets/tuples.
 
My question is, do we need to send MID messages periodically like Hellos or TC messages ? Since RFC suggests MID_INTERVAL = TC_INTERVAL and both are network wide broadcast, what is the need of so frequent MIDs.
 
Thanks in advance.
-MU

---------------------------------
Do you Yahoo!?
Yahoo! Search - Find what you’re looking for faster.

---

From: Thomas Heide Clausen <[email-masked]>
Date: Fri, 12 Mar 2004 17:36:06 +0100

On Fri, 12 Mar 2004 08:05:21 -0800 (PST)
manet user <[email-masked]> wrote:

> Hi,
>  
> I am styduying the OLSR implementations and RFC. I couldn't understand
> from the RFC, how does the communication starts in a network. 
>  
> My understanding is: 
> - every node that has multiple interfaces sends out MID messages (full
> boradcast), - each node also sends out Hello message (with no addresses
> in Data part)- nodes receving these packets create various sets/tuples.
>  
> My question is, do we need to send MID messages periodically like Hellos
> or TC messages ? Since RFC suggests MID_INTERVAL = TC_INTERVAL and both
> are network wide broadcast, what is the need of so frequent MIDs.
>  
> Thanks in advance.
> -MU

Hello,

Thanks for your interrest in OLSR.

It helps to think about it this way: an MID message is what is used to
associate "interfaces" with "nodes". I.e. the link sensing part of OLSR
detects links between interfaces -- the MID messages associate these
interfaces (and thereby links) to the notion of a "node" -- with a node
being the entities we're concirned about creating routes between in the
MANET.

The periodicity of MID messages is basically due to two things: first,
nodes may actually change their interface associations over time (e.g., a
node may decide that a given interface no longer is to be used for MANET
routing), thus interface association information must be able to expire;
second, new nodes may appear in the network at any time, thus the interface
association must be made available periodically to ensure that such "new"
nodes have the required information.

Hope this helps,

--thomas

_______________________________________________
manet mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/manet