Looking through ND-10 I think we are getting pretty close to our limits in the size of NS/NA+ARO+SLLAO.
NS/NA = 24 octets ARO = 16-32 octets SLLAO = 8-16 octets Best case = 48 octets Worst case = 72 octets We have a request from e.g. backbone-router-02 to add a new 16-bit TID field to ARO, and this is just one example for the future. There may be other options to be carried in the NS as well. Is there anything we can/should do to reduce the worst case for NS/NA? Some random thoughts: 1. What is Target Address in our unicast NS/NAs actually being used for right now? Why don't we put the Registered Address there instead of in the ARO option? That would save 16 octets. 2. Reduce the size of Registration Lifetime to 16-bits with e.g. 10 second granularity. That frees up 16-bits of reserved space. 3. Change the Length of ICMPv6 options to 4 byte granularity. Would save size in SLLAO for 16-bit addresses at least. Likely would save in other options as well. 4. Make use of the 32-bits of reserved NS/NA space? I would rather not start to re-define the NS/NA message though... Other ideas, thoughts? Zach -- Zach Shelby, Chief Nerd, Sensinode Ltd. http://zachshelby.org - My blog "On the Internet of Things" http://6lowpan.net - My book "6LoWPAN: The Wireless Embedded Internet" Mobile: +358 40 7796297 _______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan
