Subject: Question about BGP NLRI of draft-ietf-l2vpn-vpls-bgp-01.txt

From: [email-masked]
Date: Fri, 20 Feb 2004 14:49:03 +0900

Dr.Kompella , Dr.Rekhter and all.

I have some questions about draft-ietf-l2vpn-vpls-bgp-01.txt.
In "BGP NLRI for VPLS Information (Section 3.2.1 Figure 2)", 
there are a new term "VE Block Size", 
which was not in the expired draft-ietf-l2vpn-vpls-bgp-00.txt.

<up to date> draft-ietf-l2vpn-vpls-bgp-01.txt
Figure 2: BGP NLRI for VPLS Information

   +------------------------------------+
   |  Length (2 octets)                 |
   +------------------------------------+
   |  Route Distinguisher  (8 octets)   |
   +------------------------------------+
   |  VE ID (2 octets)                  |
   +------------------------------------+
   |  VE Block Offset (2 octets)        |
   +------------------------------------+
   |  VE Block Size (2 octets)          | <<==
   +------------------------------------+
   |  Label Base (3 octets)             |
   +------------------------------------+

<expired> draft-ietf-l2vpn-vpls-bgp-00.txt
Figure 2: BGP NLRI for VPLS Information

   +------------------------------------+
   |  Length (2 octets)                 |
   +------------------------------------+
   |  Route Distinguisher  (8 octets)   |
   +------------------------------------+
   |  VE ID (2 octets)                  |
   +------------------------------------+
   |  Label-block Offset (2 octets)     |
   +------------------------------------+
   |  Label Base (3 octets)             |
   +------------------------------------+
   |  Variable TLVs (0 to N octets)     |
   |              ...                   |
   +------------------------------------+

But the new document did not describe "VE Block Size".

What does "VE Block Size" mean?
And what is a difference of "VE Block Size" and "VE Block Offset"?
Why is "Block Size" necessary as well as "Block Offset"?
How are "Size" and "Offset" used in the NLRI or BGP message?

With best regards,

Owashi
[email-masked]