The MPLS WG Archive

["Adrian Farrel" <adrian@olddog.co.uk>]

> the authors of the <query on draft-rosen-mpls-explicit-null-01.txt>
> has asked that it should be accepted as a wg document.

I think this is a fine concept for WG attention and that this draft provides a good basis
for a WG draft.

Some minor questions and nits...

In the 3032 definition, it is possible to tell from the label what further action must be
taken (viz, look for an IPv4 or IPv6 address). In your proposal it is necessary to examine
the label _and_ the label stack bit to determine whether to act on the next label or on
the IP address. There is nothing wrong with this, but I wondered if you had considered a
third value "MPLS Explicit NULL label" to cover your requirements so that only one item
needs to be examined?

On the other hand, why don't we support explicit null labels for other payloads?

Nits...

Document header should probably include the key words "updates RFC3032"

Abstract refers to RFC 3032 without giving full details.

Abstract
   It has turned out that in practice there are some situations in which
   it is useful to send MPLS packets which have Explicit NULL occur
   other than at that bottom of the label stack.
Read...
   It has turned out that in practice there are some situations in which
   it is useful to send MPLS packets which have Explicit NULL
   other than at that bottom of the label stack.

In your replacements for sections i) and iii) you have
If the
        IPv4/6 Explicit NULL label was not at the bottom of the label
        stack, then the forwarding of the packet must then be based on
        the subsequent label.
In my mind "subsequent" is a difficult word since some might regard the label to use as
"previous". Can we say "next label in the stack"?

References
You also refer to RFCs 2026, 3031 and 3036.

Can we have the (new) IPR statement and copyright notice before this becomes a WG draft,
please.

Thanks,
Adrian