Subject: [mpls-tp] draft-ietf-mpls-tp-gach-gal-01 - MPLS Generic Associated Channel

From: Carlos Pignataro <[email-masked]>
Date: Thu, 29 Jan 2009 22:03:09 -0500

Hello,

I would like to send some small comments and questions on the "MPLS
Generic Associated Channel" I-D. I apologize these come after the WGLC
on the document ended. Hopefully these can be considered and are useful.

<http://tools.ietf.org/html/draft-ietf-mpls-tp-gach-gal-01>

~~~~~

2.1. Allocation of Channel Types

   Values for the Channel Type field currently used for VCCV are
   specified in RFC 4446 [6].  The functionality of any additional
   channel types will be defined in another document.  Each associated
   channel protocol solution document must specify the value to use for
   any additional channel types.

It seems that values for the Channel Type currently used are actually
specified in RFC4385  at <http://tools.ietf.org/html/rfc4385#section-6>,
before RFC 4446 includes the registry. Should also the value included in
an I-D (draft-ietf-pwe3-vccv-bfd) be included?

To allocate a new Channel Type, is a requirement that it should specify
the protocol (the Channel Type as a PID), potentially with an optional
function? And if so could it be explicitly mentioned?

~~~~~

3.1. Relationship with Existing MPLS OAM Alert Mechanisms

   These alert
   mechanisms are based on TTL expiration and/or use an IP destination
   address in the range 127/8.

These alert/intercept mechanisms also make use of the IP Router Alert
option, and the IPv6 address in the rage of 0:0:0:0:0:FFFF:127.0.0.0/104
Additionally, the TTL expiration is both IP TTL and MPLS TTL expiration.

~~~~~

3.1. Relationship with Existing MPLS OAM Alert Mechanisms

   RFC 4379 [4] and BFD for MPLS LSPs [3] have defined alert mechanisms
   that enable a MPLS LSR to identify and process MPLS OAM packets when
   the OAM packets are encapsulated in an IP header.

...

1. Introduction

   Some of these functions can be supported using tools such as
   VCCV [2], BFD [3], or LSP-Ping [4].  However, a requirement has been
...
   RFC 4379 [4] and BFD for MPLS LSPs [3] have defined alert mechanisms
   that enable a MPLS LSR to identify and process MPLS OAM packets when

Should the BFD for MPLS LSPs citation point to draft-ietf-pwe3-vccv-bfd
in addition to [3] (and mention the IP and non-IP cases)?

~~~~~

3.2.1. GAL Processing

   The Traffic Class (TC) field (formerly known as the EXP field) of the
   label stack entry containing the GAL follows the definition and
   processing rules specified and referenced in [8].

Should this citation [8] point to RFC3270 in addition?

~~~~~

Thanks,

-- Carlos.
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