Subject: Re: MPLSCP

From: [email-masked]
Date: Thu, 28 Jun 2001 18:51:55 +0200

Hello Eric,

It should be noted that this correction should also be reflected in an updated version of sections 4.2 and 5 of RFC 3032. Both sections are referring to an 'MPLS unicast' and 'MPLS multicast' code point for the PPP protocol value and ethertype (see extract
from RFC 3032 below).

Regards,

     Francis.

--------------------

** Extract from RFC 3032**
*******************************

4.3. Sending Labeled Packets

  ...

   Exactly one labeled packet is encapsulated in the PPP Information
   field, where the PPP Protocol field indicates either type hex 0281
   (MPLS Unicast) or type hex 0283 (MPLS Multicast).  The maximum length
   of a labeled packet transmitted over a PPP link is the same as the
   maximum length of the Information field of a PPP encapsulated packet.

   ...

   Note that two codepoints are defined for labeled packets; one for
   multicast and one for unicast.
   ...

5. Transporting Labeled Packets over LAN Media

   ...

   The ethertype value 8847 hex is used to indicate that a frame is
   carrying an MPLS unicast packet.

   The ethertype value 8848 hex is used to indicate that a frame is
   carrying an MPLS multicast packet.
   ...

---------------------

Eric Rosen <[email-masked]> on 28/06/2001 16:11:25

Please respond to [email-masked]

 To:      Francis ARTS/BE/ALCATEL@ALCATEL                     
                                                              
 cc:      [email-masked]                                         

 Subject: Re: MPLSCP                                          

You should implement as specified in RFC 3032.

I will write to IANA and ask them to (a) remove the 8283 value (which is not
used),  and (b) to  change the  references from  "tag switching  [davie]" to
"mpls [rfc3032]".

---

From: Eric Rosen <[email-masked]>
Date: Thu, 28 Jun 2001 13:17:18 -0400

No, RFC  3032 is correct  as written.  The  data packets need  codepoints to
distinguish  multicast from  unicast.   However, only  a  single PPP  MPLSCP
codepoint is used, not one for unicast and one for multicast.

---

From: Eric Gray <[email-masked]>
Date: Thu, 28 Jun 2001 13:33:35 -0400

Francis,

    I don't see why these changes would be required.  If you look at assigned
numbers for PPP - available at

    ftp://ftp.isi.edu/in-notes/iana/assignments/ppp-numbers

you will find that 0x0281 and 0x0283 have been assigned as specified in RFC
3032.  If you look at assigned numbers for Ethernet, available at

    http://www.iana.org/assignments/ethernet-numbers

you will similarly find that 0x8847 and 0x8848 have been assigned as specified
in RFC 3032.

    The number )- 0x8281 - is required for MPLSCP, which is independent of
Unicast/Multicast considerations.

--
Eric Gray