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[STDS-802-16-MOBILE] Some feedback on chapter 6.3.2.1.1, 6.3.2.2.7. ESF



Title: Message
On p.36, lats sentence, 16eD8 says that a packet can have multiple ESF subheaders. How does this connect to what we see in figure 21?
 
The subheader format specifies 1 length field, but can contain multiple subheaders. The individual subheaders don't have any (a la frag/pack subheaders) private length fields, nor a given fixed lentgh common to all subheaders. Hence, we see no way to implement multiple subheaders as you cannot specify boundaries between different subheaders. Seems broken to us.
 
Next point: why are ESF subheaders (6.3.2.2.7) not encrypted?
 
This goes against all other indications in the spec (all 'normal' subheaders are encrypted). The only reason we can think of to not encrypt the ESF subheaders would be that the physical layer device needs access to ESF content before the packet arrives to the MAC layer where decryption is done. If this is the case, it goes against the OSI PHY/MAC layer split, which makes it an unclean solution.
 
Would someone please comment.
 
Steve