Re: [CCAMP] Response to OIF letter regarding Interface Identifier

"Ong, Lyndon" <Lyong@Ciena.com> Tue, 20 July 2010 18:32 UTC

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Date: Tue, 20 Jul 2010 14:31:59 -0400
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From: "Ong, Lyndon" <Lyong@Ciena.com>
To: Lou Berger <lberger@labn.net>, Kimberly Chiu <kchiu@oiforum.com>, CCAMP <ccamp@ietf.org>
Subject: Re: [CCAMP] Response to OIF letter regarding Interface Identifier
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Dear Lou,

Thanks very much to you and the CCAMP members for the response to our
note, I will forward this to the OIF participants.
We appreciate your effort to complete this in time for our current
meeting.

Best regards,

Lyndon Ong



-----Original Message-----
From: Lou Berger [mailto:lberger@labn.net] 
Sent: Tuesday, July 20, 2010 11:29 AM
To: Kimberly Chiu; Ong, Lyndon; CCAMP
Subject: Response to OIF letter regarding Interface Identifier

Dear Mr. Ong,

Thank you for your letter regarding Interface Identifier dated May 21, 
2010.  The letter referenced several RFCs only some of which are 
products of the CCAMP working group.  (RFC4202 and RFC4631 are products 
of CCAMP, while RFC3477, RFC3811, RFC4220 are products of MPLS.)

In the letter you ask about the range of values allowed for an 
unnumbered link identifier.  RFC 4202 (and RFC 3477) define an 
unnumbered link being identified by a "non-zero 32-bit number that is 
unique within the scope of the LSR".  RFC4203 and RFC4205 contain 
parallel language.  RFC4201 effectively adds an additional restriction 
by introducing special semantics for the value 0xFFFFFFFF. These 
documents therefore allow an implementation to select any value that can

be represented in 32 bits other than zero and 0xFFFFFFFF.

You note in your letter that "The RFC MIBs appear to imply that the 
range is restricted to a maximum value of 2147483647."  This observation

is further supported by the InterfaceIndex and InterfaceIndexOrZero 
textual convention defined in RFC 2863, both of which have a maximum 
value of 2147483647.

Based on the above as well as the other MIBs you reference in your 
letter, it seems reasonable that an implementation will select values 
that can be fully represented in all MIBs that the implementation may 
support, i.e., up to 2147483647.  That said, the choice of an unnumbered

link identifier remains completely within the scope of an implementation

and an implementation may choose to select larger values.

Regards,
Deborah Brungard and Lou Berger
IETF CCAMP Working Group Co-Chairs

[CCAMP] Response to OIF letter regarding Interfac… Lou Berger
Re: [CCAMP] Response to OIF letter regarding Inte… Ong, Lyndon