Subject: [CCAMP] Draft response to OIF letter regarding Interface Identifier dated May 21

From: Lou Berger <[email-masked]>
Date: Wed, 14 Jul 2010 15:26:05 -0400

All,
	The enclosed is a proposed response to a letter received from the OIF. 
  Please send any comments you have by July 21.

Thank you,
Deborah and Lou

-------------------------
To: "Kimberly Chiu" <[email-masked]>
Cc: "'Ong, Lyndon'" <[email-masked]>,
      [email-masked]
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.  These documents therefore allow an implementation to 
select any value that can be represented in 32 bits other than zero.

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

---

From: Curtis Villamizar <[email-masked]>
Date: Wed, 14 Jul 2010 18:58:09 -0400

In message <[email-masked]>
Lou Berger writes:
> _______________________________________________
> CCAMP mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/ccamp

Seems fine.  2147483647 is just 2^31 - 1 so someone seems to have
assumed that the ifindex is a signed 32 bit number.

Also note that all ones is reserved in Link Bundling.  You may want to
point that out.

Curtis

---

From: Lou Berger <[email-masked]>
Date: Tue, 20 Jul 2010 14:24:03 -0400

Curtis,
	Much thanks!

All,
	The OIF has asked that we send this response ASAP, so it will be sent 
in a few minutes.  We don't expect that we'll miss any comments by 
sending it a day early.

Lou (and Deborah)

On 7/14/2010 6:58 PM, Curtis Villamizar wrote:
> In message<[email-masked]>
> Lou Berger writes:
>>
>> All,
>> To: "Kimberly Chiu"<[email-masked]>
>> Cc: "'Ong, Lyndon'"<[email-masked]>,
>>        [email-masked]