The devices that 6lowpan will be used with will have constraints on their capabilities.
- Energy -- some will be battery powered. (Note that this is different from the "daily recharge routine" for PDAs and mobile phones -- these devices need to live off an AA battery for a couple of years.)
- Code size -- some will be limited to 32KB, 64KB, 96 KB Flash
- RAM size -- 2K, 4K