Subject: I-D ACTION:draft-atlas-ospf-local-protect-cap-00.txt

From: [email-masked]
Date: Tue, 10 Feb 2004 08:14:07 -0500

A New Internet-Draft is available from the on-line Internet-Drafts
directories.

	Title		: OSPFv2 Extensions for Link Capabilities and IP/LDP
                          Local Protection
	Author(s)	: A. Atlas
	Filename	: draft-atlas-ospf-local-protect-cap-00.txt
	Pages		: 7
	Date		: 2004-2-9
	
This document proposes an extension to OSPF Version 2 for advertising
link capabilities using the extensions defined for traffic engineering.
The link capabilities are defined there for future extensibility.

To support the signaling requirements of IP Local Protection [IP-
LOCAL-PROTECT], this document defines two bits in the proposed link
capabilities extension.  Additionally, this document reserves a bit in
the Router Capabilities TLV defined in [OSPF-RTR-CAP].

This document specifies additional information that can inserted in
OSPF LSAs to convey link capabilities that may be useful in certain
applications.  In particular, a router may indicate that zero or more
of its links may be used by an upstream router as an alternate, SPT-
disjoint path to an arbitrary destination D.  Additionally, a router
may convey that zero or more of its links are capable of breaking a
U-turn, which may be described as a single-hop forwarding loop
between two router's.  This means that a router can detect the
presence of a forwarding loop by recognizing that traffic to a
destination is being received from a neighbor to which it has
forwarding state pointing back to the same neighbor for that
destination.  In such a situation, it will switch to a loop-free
node-protecting alternate until new primary forwarding state has been
installed, thus breaking the U-turn.  Therefore, the immediate
applicability for these two link capabilities is in support of local
protection in the event of a link and/or node failure while the OSPF
area is reconverging onto a new topology.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-atlas-ospf-local-protect-cap-00.txt

To remove yourself from the IETF Announcement list, send a message to 
ietf-announce-request with the word unsubscribe in the body of the message.

Internet-Drafts are also available by anonymous FTP. Login with the username
"anonymous" and a password of your e-mail address. After logging in,
type "cd internet-drafts" and then
	"get draft-atlas-ospf-local-protect-cap-00.txt".

A list of Internet-Drafts directories can be found in
http://www.ietf.org/shadow.html 
or ftp://ftp.ietf.org/ietf/1shadow-sites.txt

Internet-Drafts can also be obtained by e-mail.

Send a message to:
	[email-masked].
In the body type:
	"FILE /internet-drafts/draft-atlas-ospf-local-protect-cap-00.txt".
	
NOTE:	The mail server at ietf.org can return the document in
	MIME-encoded form by using the "mpack" utility.  To use this
	feature, insert the command "ENCODING mime" before the "FILE"
	command.  To decode the response(s), you will need "munpack" or
	a MIME-compliant mail reader.  Different MIME-compliant mail readers
	exhibit different behavior, especially when dealing with
	"multipart" MIME messages (i.e. documents which have been split
	up into multiple messages), so check your local documentation on
	how to manipulate these messages.

Below is the data which will enable a MIME compliant mail reader
implementation to automatically retrieve the ASCII version of the
Internet-Draft.