--- Samita Chakrabarti <[EMAIL PROTECTED]> wrote:
> One question, I have in mind, whether we need to define a format for
> IEEE 64bit address for lowpan - AFAIK, IEEE802.15.4 does not specify an
> address format for the 64bit MAC address. Do we know if it could be a

Sure. By default the MAC address is an EUI-64, as mentioned here:

http://www.geocities.com/gabriel_montenegro_2000/draft-ietf-6lowpan-format-00a.htm#mesh

As with many 802 devices (ethernet, token ring, fddi...) you're not forced to 
set it
to the manufacturer-set MAC address. So people quite commonly set it to other 
things
like random, or layer 2 CGAs or structured, etc. ZigBee has a structured 
addressing
scheme, and Geoff can tell you about issues with that. We've seen a similar 
proposal
in this group as well.

802.15.4 also allows the 16-bit addresses, assigned by the controller during
network entry of the device.

> random number? If we have a specific format for the address, perhaps
> we can comeup with some clever header-compression and include both
> source and destination MAC address when M bit is set.

Just using 16-bit addresses would go a long way. Not sure we should
look any further. We could include both src and dst then.

> Or just doing a multiple-unicast to the precusor list and so on. If the
> routing table maintains a precusor list, it will not be that costly 
> for the lowpan layer-code to lookup that list. The third option is to
> include a bit in the lowpan layer along with 'M' bit to ask for RERR
> or not. If the bit is 0, the RERR is not generated for the datapackets.

AODVjr, for example, does not use RERRs (or precursor lists, for that matter).

-gabriel


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