Subject: [CCAMP] Question on GMPLS protection object Class-Num in RFC 4872

From: "Daniel Cohn" <[email-masked]>
Date: Tue, 5 Oct 2010 15:27:02 +0200

Hi,

I noticed that, unlike other objects in RFC 4872, the GMPLS protection
object Class-Num (37) is not explicitly specified in the xxbbbbbb form
as per RFC 2205, section 3.10 Future Compatibility. 

I see two possible interpretations of this fact:

1.- This object is implicitly encoded in the Class-Num = 0bbbbbbb form,
meaning that a transit LSR that does not support this object should
reject the entire message and return "unknown object class". Therefore
an LSP with protection type specified in the GMPLS protection object
cannot be established  thru LSRs that don't support the object.

2.- The decision on the encoding of the two high-order bits is left to
the LSP head, depending on the desired behavior for transit LSRs that
don't support the GMPLS protection object.

Can you please let me know your thoughts on this?

Thanks,

Daniel Cohn

System Engineer

Orckit-Corrigent

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From: Lou Berger <[email-masked]>
Date: Tue, 05 Oct 2010 19:50:22 -0400

Daniel,
	There's not much room for interpreting this:

[RFC 3473]
    6. Protection Object

    The use of the Protection Object is optional.  The object is included
    to indicate specific protection attributes of an LSP.  The Protection
    Object uses Class-Number 37 (of form 0bbbbbbb).

[RFC2205]
            o    Class-Num = 0bbbbbbb

                 The entire message should be rejected and an "Unknown
                 Object Class" error returned.

Lou

On 10/5/2010 9:27 AM, Daniel Cohn wrote:
> reject the entire message and return “unknown object class”. Therefore
> cannot be established thru LSRs that don’t support the object.
>
> don’t support the GMPLS protection object.
>
> _______________________________________________
> CCAMP mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/ccamp

---

From: "Daniel Cohn" <[email-masked]>
Date: Wed, 6 Oct 2010 10:04:34 +0200

Hi Lou, thanks for pointing me to RFC 3473, I agree the wording there is
unambiguous. 

It would have been helpful if RFC 4872 mentioned this too.

Regards,

Daniel

-----Original Message-----
From: Lou Berger [mailto:[email-masked]] 
Sent: Wednesday, October 06, 2010 1:50 AM
To: Daniel Cohn
Cc: [email-masked]
Subject: Re: [CCAMP] Question on GMPLS protection object Class-Num in
RFC 4872

Daniel,

[RFC 3473]
    6. Protection Object

    The use of the Protection Object is optional.  The object is
included
    to indicate specific protection attributes of an LSP.  The
Protection
    Object uses Class-Number 37 (of form 0bbbbbbb).

[RFC2205]
            o    Class-Num = 0bbbbbbb

Lou

---

From: Lou Berger <[email-masked]>
Date: Wed, 06 Oct 2010 07:04:11 -0400

I don't see RFC 4872 (i.e., "PROTECTION object: Class-Num = 37") as any 
less ambigious.

Lou