TEAS Working Group Yi Lin
Internet Draft Huawei Technologies
Intended status: Standards Track Bin Yeong Yoon
ETRI
Expires: September 2020 March 9, 2020
RSVP-TE Extensions in Support of Proactive Protection
draft-lin-teas-gmpls-proactive-protection-00.txt
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other documents
at any time. It is inappropriate to use Internet-Drafts as
reference material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
This Internet-Draft will expire on September 9, 2020.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with
respect to this document. Code Components extracted from this
document must include Simplified BSD License text as described in
Yi Lin et. al Expires September 9, 2020 [Page 1]
Internet-Draft GMPLS Proactive Protection March 2020
Section 4.e of the Trust Legal Provisions and are provided without
warranty as described in the Simplified BSD License.
Abstract
This document describes protocol-specific procedures and extensions
for Generalized Multi-Protocol Label Switching (GMPLS) Resource
ReSerVation Protocol - Traffic Engineering (RSVP-TE) signaling to
support Label Switched Path (LSP) Proactive Protection, which create
the protecting LSP after a failure is predicted and before it
becomes a real failure.
Table of Contents
1. Introduction .................................................. 2
2. Conventions used in this document ............................. 3
3. Overview of Predicted Failure and Related Recovery Methods .... 3
3.1. Predicted Failure ........................................ 3
3.2. Proactive Protection ..................................... 4
4. Modified PROTECTION Object Format ............................. 6
5. Extension to ERROR_SPEC Object ................................ 7
5.1. New Error Code / Sub-code ................................ 7
5.2. New TLVs in ERROR_SPEC Object ............................ 7
6. End-to-end Proactive Protection ............................... 8
6.1. Creation of the Protected LSP ............................ 8
6.2. Notification of Predicted Failure Event .................. 9
6.3. Tearing Down of the Protecting LSP ....................... 9
7. Proactive Segment Protection ................................. 10
7.1. Creation of the Protected LSP ........................... 10
7.2. Notification of Predicted Failure Event ................. 11
7.3. Tearing Down of the Segment Recovery LSP ................ 12
7.4. Priority and Resource Pre-emption ....................... 12
8. Consideration of Backward Compatibility ...................... 14
9. Security Considerations ...................................... 14
10. IANA Considerations.......................................... 14
11. References .................................................. 14
11.1. Normative References ................................... 14
11.2. Informative References ................................. 15
12. Authors' Addresses .......................................... 15
1. Introduction
[RFC4872] and [RFC4873] describe protocol-specific procedures and
extensions for GMPLS RSVP-TE signaling to support end-to-end LSP
Yi Lin et. al Expires September 9, 2020 [Page 2]
Internet-Draft GMPLS Proactive Protection March 2020
recovery (including protection and restoration) and segment LSP
recovery, respectively.
Traditional protection solution (e.g., 1+1 or 1:1 protection) could
have very fast protection switch after failure happens, but takes
twice of resource in the network during the whole lifetime of the
LSP. On the other hand, the traditional restoration solution has
much higher resource use, but the recovery of the LSP is much
slower, due to the additional signaling time to create the
restoration LSP.
In order to reduce the recovery resource while keeping the very fast
protection switch, an approach is to use the failure prediction
technologies and to create 1+1 or 1:1 protection only when a
potential failure is predicted. This approach refers to "Proactive
Protection" in this document.
This document extends the RSVP-TE protocol to support the control of
the Proactive Protection.
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Overview of Predicted Failure and Related Recovery Methods
3.1. Predicted Failure
In most cases, there will be some indications before a physical
failure happens in a network. For example, abnormal fluctuation of
noise of a lightpath, BER (Bit Error Rate) (before error correction)
rising, temperature rising of a transponder.
Therefore, by monitoring on certain physical parameters and
analyzing the change tendency using, for example, Machine Learning
(ML) or other technologies, a node is possible to predict whether
failure will happen in an upcoming period of time.
Note that a predicted failure is different from a Signal Degrade in
that:
- When Signal Degrade happens to a connection, the connection is
still available but the quality of the signal carried by this
Yi Lin et. al Expires September 9, 2020 [Page 3]
Internet-Draft GMPLS Proactive Protection March 2020
connection has declined and is lower than the predetermined
threshold. For example, the BER of a connection rises and is out
of tolerance.
- When a predicted failure of a connection is inferred, no failure
nor degradation happens at present, but there is a trend that
after a period of time, failure will probably happen, which will
cause Signal Fail or Signal Degrade.
The methods to predict failures are outside the scope of this
document.
3.2. Proactive Protection
The "Proactive Protection" refers to an LSP protection approach
which create the protecting LSP after a failure is predicted and
before it becomes a real failure. Both end-to-end protection
(defined in [RFC4872] and segment protection (defined in [RFC4873])
are applicable for the Proactive Protection.
The main procedure of Proactive Protection is shown in Figure 1:
|-> Predicted failure detected
| |-> Proactive Protecting path created
| | |-> Real failure happens, triggering
| | | protection switch
| | |
| | | |-> Protection switch finished
| | t3 | |
---?---+********+******X*+===================================> t
t1 t2 | t4 t5
|
|-->Prediction: failure will happen after t3
Case 1: Predicted failure happens as predicted
Yi Lin et. al Expires September 9, 2020 [Page 4]
Internet-Draft GMPLS Proactive Protection March 2020
|-> Predicted failure detected
| |-> Proactive Protecting path created
| |
| | Predicted failure disappeared
| | i.e., the predicted failure <-|
| | will not become real failure | |-> Protecting
| | | | path deleted
| | t3 | |
---?---+********+**************************O***+-------------> t
t1 t2 | t6 t7
|
|-->Prediction: failure will happen after t3
Case 2: Predicted failure disappeared and will not happen
?: Predicted failure
X: Real failure happen
O: Predicted failure disappeared
----: No protecting path
****: protecting path created, traffic carried by protected path
====: protecting path created, traffic carried by protecting path
Figure 1: Overview of Proactive Protection
- t1: The protection source node of an LSP is notified that a
failure will probably happen after t3, so it starts to create 1+1
or 1:1 protection of the connection. Here the protection source
node can be the source node of the LSP (for end-to-end protection
case), or a branch node located between the source node and the
predicted failure point of the LSP (for segment protection case).
- t2: The 1+1 or 1:1 protecting path is created between the
protection source node and the protection destination node. Here
the protection destination node can be the destination node of the
LSP (for end-to-end protection case), or a merge node located
between the predicted failure point and the destination node of
the LSP (for segment protection case).
Note that at t2, since there is no real failure or signal
degradation happened, the protection switch will not be triggered,
and the traffic still remains in the protected path.
- t4: If real failure happens as predicted, the 1+1 or 1:1
protection switch will be triggered.
- t5: Protection switch finished and the traffic is now switched to
the protecting path.
Yi Lin et. al Expires September 9, 2020 [Page 5]
Internet-Draft GMPLS Proactive Protection March 2020
- The intermediate node, which detected the predicted failure, will
continue to monitor the change tendency of the related physical
parameters to make further prediction before the predicted failure
becomes a real failure. If, at t6, the intermediate node finds
that the change tendency causing the predicted failure disappeared
and the status is stable enough, i.e., the intermediate node
confirms that the predicted failure will not become real failure,
it MAY send another notification to clear the predicted failure.
In this case, the protection source node MAY decide to tear down
the protecting path at t7 after t6, in order to save the network
resource.
4. Modified PROTECTION Object Format
This document modifies the PROTECTION object (C-Type=2) by adding
two new bits T and A in reserved fields, as shown in Figure 2 below:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | Class-Num(37) | C-Type (2) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|S|P|N|O|T| Res. | LSP Flags | Reserved | Link Flags|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|I|R|A| Reserved | Seg.Flags | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: The modified PROTECTION object (C-Type=2)
- T (Triggered End-to-end Proactive Protection): 1 bit, when set
(1), it indicates that the end-to-end Proactive Protection are
required.
Note that if T bit is set (1), the LSP Flags SHOULD be one of:
0x04 1:N Protection with Extra-Traffic
0x08 1+1 Unidirectional Protection
0x10 1+1 Bidirectional Protection
- A (proActive Segment Protection): 1 bit, when set (1), it
indicates that the Proactive Segment Protection are required.
Note that If A bit is set (1), the Seg. Flags SHOULD be one of:
0x04 1:N Protection with Extra-Traffic
0x08 1+1 Unidirectional Protection
0x10 1+1 Bidirectional Protection
See [RFC4872] and [RFC4873] for the definition of other fields.
Yi Lin et. al Expires September 9, 2020 [Page 6]
Internet-Draft GMPLS Proactive Protection March 2020
5. Extension to ERROR_SPEC Object
5.1. New Error Code / Sub-code
Two new Error Sub-codes under Error Code "25 - Notify Error" are
defined in this document, which are used to notify the event of a
predicted failure and the event of disappearance of the previous
predicted failure:
Error Code = 25: "Notify Error" (see [RFC3209])
Error Sub-code = TBA1: "Notify Error/LSP Local Predicted Failure"
Error Sub-code = TBA2: "Notify Error/LSP Local Predicted Failure
disappeared"
5.2. New TLVs in ERROR_SPEC Object
When predicting a failure, a certain time before which the failure
may happen may also be predicted. This time information is useful
for the source node to know how long it should wait for the
predicted failure to become a real failure, and to decide when it's
safe to tear down the protecting LSP if the predicted failure didn't
happen.
A new TLV in IPv4/IPv6 IF_ID ERROR_SPEC Object is defined in this
document, which is used to indicate the time before which the
predicted failure will probably become real failure. The format of
this new TLV is shown in Figure 3 below:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = TBA3 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Predicted Failure ID | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| Cause of the Predicted Failure |
~ | Padding Bits ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: New TLV (type=TBA3) in ERROR_SPEC Object
- Type: TBA3
- Length: variable and MUST be equal or greater than 8, the total
length of the whole TLV in Byte, including the Type and Length
Yi Lin et. al Expires September 9, 2020 [Page 7]
Internet-Draft GMPLS Proactive Protection March 2020
fields.
- Predicted Failure ID: an ID to identify the predicted failure,
which is unique within the scope of the node predicting the
failure.
- Cause of the Predicted Failure: the cause of the predicted failure
in text format. It SHOULD be a string of printable ASCII
characters, without a NULL terminator. This field is optional. If
there is no information for this field, the padding bits (16 bits)
will be filled immediately after the "Predicted Failure ID" field.
- Padding Bits: Added after the "Cause of the Predicted Failure"
field to make the whole TLV a multiple of four bytes if necessary.
Padding bits MUST be set to 0 and MUST be ignored on receipt.
Another new TLV in IPv4/IPv6 IF_ID ERROR_SPEC Object is defined in
this document, which is used to indicate the disappearance of the
previous predicted failure. The format of this new TLV is shown in
Figure 4 below:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = TBA4 | Length = 8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Predicted Failure ID | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: New TLV (type=TBA4) in ERROR_SPEC Object
- Type: TBA4
- Length: 8.
- Predicted Failure ID: the ID of the previous predicted failure
which is now disappeared.
- Reserved: MUST be zero.
6. End-to-end Proactive Protection
6.1. Creation of the Protected LSP
To create an LSP with recovery type of "End-to-end Proactive
Protection", the source node of the LSP generates a Path message
with a PROTECTION object included. The T bit in the PROTECTION
Yi Lin et. al Expires September 9, 2020 [Page 8]
Internet-Draft GMPLS Proactive Protection March 2020
object MUST be set to 1 (End-to-end Proactive Protection), so that
all other nodes along the LSP can start the failure prediction
function on related links/nodes.
Note that the N bit in the PROTECTION object is used to indicate
whether the control plane message exchange is only used for
notification or for protection-switching purpose after real failure
happens, see [RFC4872]. In other words, the N bit have nothing to do
with the notification of a predicted failure before real failure
happens.
To allow the notification of predicted failure event to the source
node by the Notify message, the NOTIFY REQUEST object MUST also be
included in the Path message (see [RFC3473]), where the "Notify Node
Address" SHOULD be the address of the source node of the LSP.
6.2. Notification of Predicted Failure Event
When an intermediate node on an LSP infers that a failure will
happen and will affect the LSP, a Notify message will be sent to the
source node of the LSP, to inform such predicted failure event. A
new error code/sub-code "Notify Error/LSP Local Predicted Failure"
is used in the ERROR_SPEC object or IF_ID_ERROR_SPEC object in the
Notify message.
The Notify message SHOULD include a TLV (type = TBA3) in the IPv4 or
IPv6 IF_ID_ERROR_SPEC object, to indicate the ID and the cause of
the predicted failure.
On receiving the Notify message with error code/sub-code "Notify
Error/LSP Local Predicted Failure", the source node of the LSP
SHOULD trigger the procedure to create the protecting LSP, according
to the protection type indicated in the "LSP Flags" field of the
PROTECTION object in the Path message for the protected LSP. The
procedures of creating the protecting LSP and the protection
switching after real failure happens are described in [RFC4872],
except that the T bit in the PROTECTION object of this new Path
message MUST set to 1.
The source node SHOULD also store the ID of the predicted failure
and create the association between this ID and the created
protecting LSP locally.
6.3. Tearing Down of the Protecting LSP
After sending Notify message to the source node for notifying the
predicted failure, the intermediate node will continue to monitor
Yi Lin et. al Expires September 9, 2020 [Page 9]
Internet-Draft GMPLS Proactive Protection March 2020
the change tendency of the related physical parameters to make
further prediction. If it confirms that the change tendency causing
the predicted failure disappeared and the predicted failure will not
become real failure, it MAY send another Notify message with error
code/sub-code "Notify Error/LSP Local Predicted Failure
disappeared", to clear the previous predicted failure.
The Notify message SHOULD include a TLV (type = TBA4) in the IPv4 or
IPv6 IF_ID_ERROR_SPEC object, to indicate the ID of the previous
predicted failure which is now disappeared. The value of this ID
MUST equal to the one in the previous Notify message sent to the
source node to notify this predicted failure.
On receiving the Notify message with error code/sub-code "Notify
Error/LSP Local Predicted Failure disappeared", the source node of
the LSP SHOULD check if it has received the Notify message from the
same intermediate node before, with the same ID of the predicted
failure:
- If yes, and if the protecting LSP has already been created, the
source node MAY trigger the procedure to tear down the protecting
LSP. See [RFC4872] about the process of tearing down a protecting
LSP. Note that the source node MAY wait for a certain period of
time before tearing down the protecting LSP, according to local
policy. Implementations SHOULD allow this policy to be configured
to provide a default across all LSPs on a node, but SHOULD also
allow it to be configured per LSP.
- If no, this Notify message can be simply ignored.
7. Proactive Segment Protection
7.1. Creation of the Protected LSP
To create an LSP with recovery type of "Proactive Segment
Protection", the source node of the LSP generates a Path message,
where:
- A PROTECTION object is included, where the A bit MUST be set to 1
(Proactive Segment Protection), so that all nodes along the
protected LSP can start the failure prediction function on related
links/nodes if supported. The "Seg. Flags" are used to indicate
the protection type of the Proactive Segment Protection.
- One or more SERO objects MAY included (i.e., explicit Proactive
Segment Protection), indicating the branch node and the merge node
of each segment recovery LSP. If no SERO object is included, it
Yi Lin et. al Expires September 9, 2020 [Page 10]
Internet-Draft GMPLS Proactive Protection March 2020
indicates that the dynamic Proactive Segment Protection method is
used.
- A NOTIFY REQUEST object is included, where the Notify Node
Address" SHOULD be the address of the source node of the LSP.
For explicit Proactive Segment Protection, when a branch node
receives a Path message with A bit set to 1 in the PROTECTION
object, the branch node follows [RFC4873] to process the Path
message, except that the Path message for the recovery LSP will not
be generated and be sent at this stage. Also, one more NOTIFY
REQUEST object SHOULD be added to the Path message of the protected
LSP, which carries the address of this branch node.
For dynamic Proactive Segment Protection, when an intermediate node
receives a Path message with A bit set to 1 in the PROTECTION
object, the node will determine if it has the ability to be a branch
node, as described in Section 6.2 of [RFC4873]. If yes, it follows
the same procedure as what a branch node does in the case of
explicit Proactive Segment Protection, as described above. If not,
the node only follows the standard procedure to create the protected
LSP.
7.2. Notification of Predicted Failure Event
When an intermediate node between a pair of branch and merge nodes
on an LSP infers that a failure will happen and will affect the LSP,
a Notify message will be sent to the nearest branch node on the
upstream direction of the LSP, to inform such predicted failure
event. The error code/sub-code "Notify Error/LSP Local Predicted
Failure" is used in the ERROR_SPEC object or IF_ID_ERROR_SPEC object
in the Notify message.
Similar to End-to-end Proactive Protection, the Notify message
SHOULD include a TLV (type = TBA3) in the IPv4 or IPv6
IF_ID_ERROR_SPEC object, to indicate the ID and the cause of the
predicted failure.
On receiving the Notify message with error code/sub-code "Notify
Error/LSP Local Predicted Failure", the branch node on the protected
LSP SHOULD generate a new Path message, and send this new Path
message along the segment recovery LSP between the branch and the
merge nodes. The procedures of generating new Path message and
creating the segment recovery LSP are the same as what is described
in [RFC4873], except that the A bit in the PROTECTION object of this
new Path message MUST set to 1.
Yi Lin et. al Expires September 9, 2020 [Page 11]
Internet-Draft GMPLS Proactive Protection March 2020
The branch node SHOULD also store the ID of the predicted failure
and create the association between this ID and the created segment
recovery LSP locally.
7.3. Tearing Down of the Segment Recovery LSP
After sending Notify message to the branch node for notifying the
predicted failure, the intermediate node will continue to monitor
the change tendency of the related physical parameters to make
further prediction. If it confirms that the change tendency causing
the predicted failure disappeared and the predicted failure will not
become real failure, it MAY send another Notify message with error
code/sub-code "Notify Error/LSP Local Predicted Failure
disappeared", to clear the previous predicted failure.
The Notify message SHOULD include a TLV (type = TBA4) in the IPv4 or
IPv6 IF_ID_ERROR_SPEC object, to indicate the ID of the previous
predicted failure which is now disappeared. The value of this ID
MUST equal to the one in the previous Notify message sent to the
branch node to notify this predicted failure.
On receiving the Notify message with error code/sub-code "Notify
Error/LSP Local Predicted Failure disappeared", the branch node of
the LSP SHOULD check if it has received the Notify message from the
same intermediate node before, with the same ID of the predicted
failure.
- If yes, and if the segment recovery LSP has already been created,
the branch node MAY trigger the procedure to tear down the segment
recovery LSP. See [RFC4873] about the process of tearing down a
segment recovery LSP. Note that the branch node MAY wait for a
certain period of time before tearing down the segment recovery
LSP, according to local policy. Implementations SHOULD allow this
policy to be configured to provide a default across all LSPs on a
node, but SHOULD also allow it to be configured per LSP.
- If no, this Notify message can be simply ignored.
7.4. Priority and Resource Pre-emption
It's possible that after recovery LSP is created and before the
predicted failure becomes a real failure, another real failure
happens on the LSP outside the protected segment. In this case, the
source node (or an intermediate node in the upstream direction of
the real failure) may start a restoration procedure to recover the
LSP. For the same protected LSP, since recovering from a real
failure always has higher priority than protecting against a
Yi Lin et. al Expires September 9, 2020 [Page 12]
Internet-Draft GMPLS Proactive Protection March 2020
predicted failure which still hasn't happened, the restoration LSP
can pre-empt the resource of the segment recovery LSP.
As shown in Figure 5, assume that node B (branch node) was notified
of a predicted failure event between N-4 and M (merge node), and has
created the segment recovery LSP along B, N-1, N-2, N-3 and M. If
another failure between S (source node) and B happens before the
predicted failure becomes a real failure, node S will try to create
the restoration LSP. Since that resource is limited, the restoration
LSP can pre-empt the resource of the segment recovery LSP between N-
1 and N-3.
The nodes along the segment recovery LSP has enough information to
determine whether pre-emption is allowed. This is because these
nodes know that:
- The current segment recovery LSP is used for Proactive Segment
Protection through the A bit in the PROTECTION object;
- The segment recovery LSP and the restoration LSP are protecting
the same LSP through the association relationship.
|<------ Pre-emption ------>|
| |
***************************************************************
*+---+ +---+ +---+ +---+ +---+*
*| +---------+N-1+---------+N-2+---------+N-3+---------+ |*
*+-+-+ +-+-+ +---+ +-+-+ +-+-+*
* | |###########################| | *
* | |# #| | *
* | |# #| | *
*+-+-+ +-+-+ +---+ +-+-+ +-+-+*
***| S +----X----+ B +---------+N-4+----?----+ M +---------+ D |***
+---+ +---+ +---+ +---+ +---+
===================================================================
S: Source node D: Destination node
B: Branch node M: Merge node
X: Real failure ?: Predicted failure (haven't happened yet)
=====: Protected LSP
#####: Segment Recovery LSP
*****: Restoration LSP
Figure 5: Resource pre-emption by restoration LSP
Yi Lin et. al Expires September 9, 2020 [Page 13]
Internet-Draft GMPLS Proactive Protection March 2020
8. Consideration of Backward Compatibility
TBD.
[Editor's note]: will add some description about interwork with
legacy nodes which do not support the function of failure prediction
and reporting.
9. Security Considerations
TBD.
10. IANA Considerations
IANA assigns values to RSVP protocol parameters. Within the current
document, two new Error code/sub-code values are defined:
Error Code = 25: "Notify Error" (see [RFC3209])
o "Notify Error/LSP Local Predicted Failure" (TBA1)
o "Notify Error/LSP Local Predicted Failure disappeared" (TBA2)
11. References
11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI
10.17487/RFC2119, March 1997.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, December 2001.
[RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) Extensions", RFC 3473,
January 2003.
[RFC4872] Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou,
Ed., "RSVP-TE Extensions in Support of End-to-End
Generalized Multi-Protocol Label Switching (GMPLS)
Recovery", RFC 4872, May 2007.
[RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel,
"GMPLS Segment Recovery", RFC 4873, May 2007.
Yi Lin et. al Expires September 9, 2020 [Page 14]
Internet-Draft GMPLS Proactive Protection March 2020
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017.
11.2. Informative References
[RFC4426] Lang, J., Ed., Rajagopalan, B., Ed., and D. Papadimitriou,
Ed., "Generalized Multi-Protocol Label Switching (GMPLS)
Recovery Functional Specification," RFC 4426, March 2006.
12. Authors' Addresses
Yi Lin
Huawei Technologies
H1, Huawei Xiliu Beipo Village, Songshan Lake
Dongguan
Guangdong, 523808 China
Email: yi.lin@huawei.com
Bin Yeong Yoon
ETRI
Email: byyun@etri.re.kr
Yi Lin et. al Expires September 9, 2020 [Page 15]