Re: [IPFIX] IPFIX: boolean, dot1qDEI and dot1qCustomerDEI

Yaakov,

> Fine with me since it simplifies the interpretation (DEI=0 means green 
> and DEI=1 means yellow).
>
> By first bitdo you mean least significant bit?
>

Yes. If needs be we could add a figure something like so:

	   0     1     2     3     4     5     6     7
	+-----+-----+-----+-----+-----+-----+-----+-----+
	|                Reserved                 | DEI |
	+-----+-----+-----+-----+-----+-----+-----+-----+


Although if we were defining this again, it might be more useful to 
retain the DEI position, and potentially include the PCP bits.

So, per 802.1Q-2011 Figure 9-1 (attached) :

	   0     1     2     3     4     5     6     7
	+-----+-----+-----+-----+-----+-----+-----+-----+
	|       PCP       | DEI |        Reserved       |
	+-----+-----+-----+-----+-----+-----+-----+-----+


However I suspect that this is incompatible with current 
implementations, so the change is not possible?

P.


> *From:*Paul Aitken [mailto:[email protected]]
> *Sent:* 02 September, 2013 21:46
> *To:* IETF IPFIX Working Group; [email protected]
> *Cc:* Yaakov Stein
> *Subject:* IPFIX: boolean, dot1qDEI and dot1qCustomerDEI
>
> Dear IPFIX experts,
>
> While reviewing IANA's IPFIX registry, I noticed that although IEs 
> #388 dot1qDEI and #389 dot1qCustomerDEI are defined as "boolean" their 
> definitions do not correspond to that type.
>
> As a reminder, RFC5101bis says:
>
> 6.1.5.  boolean
>   
>     The boolean data type is specified according to the TruthValue in
>     [RFC2579].  It is encoded as a single-octet integer per
>     Section 6.1.1,with the value 1 for true and value 2 for false.
>     Every other value is undefined.
>
>
> (for consistency with MIB truthValue).
>
> So a boolean IE cannot capture a bit field such as the DEI required by 
> #388 and #389. I checked the other boolean IEs, and they're fine.
>
> To correct this, I propose that #388 and #389 be changed from 
> "boolean" to "unsigned8", in line with all the other flags fields:
>
> 388
>
> 	
>
> dot1qDEI
>
> 	
>
> boolean
> unsigned8
>
> 	
>
> flags
>
> 	
>
> current
>
> 	
>
>
> The first bit of this octet is the value of the 1-bit Drop Eligible 
> Indicator (DEI) field of the VLAN tag as described in 802.1Q-2011 
> subclause 9.6. In case of a QinQ frame, it represents the outer tag's 
> DEI field and in case of an IEEE 802.1ad frame it represents the DEI 
> field of the S-TAG. Note: in earlier versions of 802.1Q the same bit 
> field in the incoming packet is occupied by the Canonical Format 
> Indicator (CFI) field, except for S-TAGs.
> The remainder of this octet is reserved for future use.
>
> 389
>
> 	
>
> dot1qCustomerDEI
>
> 	
>
> boolean
> unsigned8
>
> 	
>
> flags
>
> 	
>
> current
>
> 	
>
>
> In case of a QinQ frame, the first bit of this octet it represents the 
> inner tag's Drop Eligible Indicator (DEI) field and in case of an IEEE 
> 802.1ad frame it represents the DEI field of the C-TAG.
> The remainder of this octet is reserved for future use.
>
>
>
> Feedback?
>
> P.
>

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