Subject: [mpls-tp] Comments on draft-fbb-mpls-tp-data-plane RFC5332

From: Rui Costa <[email-masked]>
Date: Mon, 15 Mar 2010 23:55:20 +0000

Greetings,	

Taking into account the information below, quoted from "draft-fbb-mpls-tp-data-plane" and RFC5332:	

Is 5.1.1 right about DMAC 01-00-5E-XX-XX-XX or should it be more precisely 01-00-5e-8v-wx-yz, as in RFC5332?	

Although i suppose that R3 (quote below) stands for an LSR, should we say that, for say NMS-based provisioning, label bindings are "upstream-assigned" and thus for DMACs 01-00-5E-XX-XX-XX one must use ETHtype 0x8848?	

Thanks for your time. Regards,	
Rui

[QUOTES]	
In "draft-fbb-mpls-tp-data-plane"	
5.1.1.  Destination MAC Address Determination	
[...]	
   The preferred approach is therefore to use as the destination MAC	
   address an Ethernet multicast address reserved for MPLS-TP.  The	
   address allocated for this purpose by the Internet Assigned Numbers	
   Authority (IANA) is 01-00-5E-XX-XX-XX.  An MPLS-TP implementation	
   MUST process Ethernet frames received with this destination MAC	
   address by default.	

In RFC5332, "MPLS Multicast Encapsulations"	
3.  Upstream-Assigned vs. Downstream-Assigned	
[...]	
   If the binding between L and F was made by a third party, say R3, and	
   then advertised to both R1 and R2, we also refer to the label binding	
   as "upstream-assigned".	
[...]	
4.  Ethernet Codepoints	

   Ethertype 0x8848, formerly known as the "MPLS multicast codepoint",	
   is to be used only when an MPLS packet whose top label is upstream-	
   assigned is carried in a multicast ethernet frame.	
[...]	
8.  Ethernet MAC DA for Multicast MPLS	

   When an LSR transmits a multicast MPLS packet in a multicast Ethernet	
   frame, it MUST set the MAC Destination Address to the value	
   01-00-5e-8v-wx-yz, where vwxyz is a 20-bit (five-nibble) value set as	
   follows:	

      1. vwxyz MAY be set to 0,	

      2. vwxyz MAY be set to the value of one of the MPLS labels on the	
         packet's label stack.