Subject: [mobile-ip] question on MIPv4 long/short extension formats

From: "Niko A. Fikouras" <[email-masked]>
Date: Mon, 26 May 2003 11:56:08 +0200

<With apologies to Niko, I just returned from vacation 
     to find this in my bounce folder.  For the benefit of
     the alais, as well as to get Nikos question answered
     (if it hasn't been already), here it is.   -- Steve)

Hi all,

in RFC3344 sections 1.10 and 1.11 define respectively the long and short 
extension formats. I would be grateful if anyone could answer the 
following questions:

Is it possible for a certain Type to define different Sub-Types each 
following a different (short/long) extension format, i.e. for Type 1, 
Sub-Type 10 follows the short extension format while Sub-Type 11 follows 
the long extension format.

Assuming that the previous case is correct, a mip software processing 
such extensions would determine their Length with the help of the 
Sub-Type. However, in the short extension format the Sub-Type field is 
preceded by the Length field. In that case, the mip software would not 
know whether to interpret the second byte of the extension as a Length 
field or as a Sub-Type field.

Thanks in advance
niko