Re: Label Set Object

[Dimitri.Papadimitriou@alcatel.be]

ben,

> 2. the Label Type and Length fields from the Label Set object header imply
> the lengths of the subchannels and therefore no extra headers are needed
> for the subchannels (as is the case in ERO and RRO subobjects).

the label type field allows to know the length of each sub-entity
these values are processed wrt to the action field; also remember
that the generalized label does not identify its "type" instead, 
the nodes are expected to know from the context what type of label 
to expect
 
> What is the definition of "Label Type"?  C-types 2 and 3 for generalized
> label objects and waveband label objects respectively?

indicates the type and format of the labels carried in the object;
values match the C-Type of the appropriate rsvp_label object

only the low order 8 bits are used in this field; all info can be 
derived from this

> For 3 it is fixed, but for 2 it could be variable length, even though 32
> bits are currently the norm.

all C-Type 2 have a 32-bit length (except C-Type 3): port,
wavelength and tdm labels as well as generic mpls labels,
atm and frame relay labels are encoded right justified 
aligned in 32 bits (4 octets)

> This should be more clearly defined.

it is clearly defined i think, in brief no "extra object
header is needed"

thanks,
- dimitri.

schultz@io.iol.unh.edu wrote:
> 
> Hello,
> 
> There is currently a hot argument over the definition of "subchannel"
> text in the definition of the label set object in RFC 3473.
> 
> Does each subchannel contain a complete generalized label object with a
> complete header?  There are 2 arguments here:
> 
> 1. each generalized object is variable length field, thus each subchannel
> must have an embeded generalized label object.  This will solve the
> variable length feature.
> 
> 2. the Label Type and Length fields from the Label Set object header imply
> the lengths of the subchannels and therefore no extra headers are needed
> for the subchannels (as is the case in ERO and RRO subobjects).
> 
> What is the definition of "Label Type"?  C-types 2 and 3 for generalized
> label objects and waveband label objects respectively?
> 
> For 3 it is fixed, but for 2 it could be variable length, even though 32
> bits are currently the norm.
> 
> This should be more clearly defined.
> 
> Thanks,
> -Ben

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Papadimitriou Dimitri 
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