Hi,

 

I think there is a little problem with PCEP object TLV format.

 

The main problem being that the general format of the TLVs is not described
(Type, length value length, 4 bytes alignment.).

 

Besides for existing TLVs we have:

 

 

"The REQ-MISSING TLV is composed of 1 byte for the type,

1 byte specifying the number of bytes in the value field, 2 bytes

for an "Unused" field (the value of which MUST be set to 0), followed by

a fix length value field of 4 bytes specifying the request-id-number

that correspond to the missing request. 

The REQ-MISSING TLV is padded to eight-byte alignment.

 

TYPE: To be assigned by IANA

LENGTH: 4

VALUE: request-id-number that corresponds to the missing request"

 

I think the LENGTH field should be set to 6, the unused field 2 bytes being
part of the Value field. Otherwise

it means those 2 bytes are part of the TLV header and it should be said that
all TLVs will be formatted with

this 4 bytes header i.e. Type (1byte) - Value field Length (1byte) - Unused
field (2bytes) - Value field

Otherwise, there may be some problem when decoding a message with unknown
TLV.

 

Besides I'm not sure about the "The REQ-MISSING TLV is padded to eight-byte
alignment." statement.

Is it really needed?

 

For the NO-PATH-VECTOR TLV we have

 

"The NO-PATH-VECTOR TLV is composed of 1 byte for the type, 1 byte

   specifying the number of bytes in the value field, followed by a fix

   length value field of 32-bits flags field used to report the

   reason(s) that led to unsuccessful path computation.

 

   The NO-PATH-VECTOR TLV is padded to eight-byte alignment.

 

TYPE: To be assigned by IANA

 

   LENGTH: 4

 

   VALUE: 32-bits flags field"

 

In this case there is no Unused field 2 bytes. 

I think it would be better to have the same format for all TLVs of all
object.

And again I'm wondering if the LENGTH field should be set to 4 or 6?

 

Can you please clarify this to me? Am I missing something?

 

Thanks

Fabien

 

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