draft-ietf-ccamp-confirm-data-channel-status-09.txt   rfc5818.txt 
Network Working Group D. Li
Internet Draft H. Xu
Category: Standards Track Huawei
S. Bardalai
Fujitsu
J. Meuric
France Telecom
D. Caviglia
Ericsson
Expires: June 2010 December 14, 2009
Data Channel Status Confirmation Extensions
for the Link Management Protocol
draft-ietf-ccamp-confirm-data-channel-status-09.txt Internet Engineering Task Force (IETF) D. Li
Request for Comments: 5818 H. Xu
Category: Standards Track Huawei
ISSN: 2070-1721 S. Bardalai
Fujitsu
J. Meuric
France Telecom
D. Caviglia
Ericsson
April 2010
Status of this Memo Data Channel Status Confirmation Extensions
for the Link Management Protocol
This Internet-Draft is submitted to IETF in full conformance with the Abstract
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering This document defines simple additions to the Link Management
Task Force (IETF), its areas, and its working groups. Note that Protocol (LMP) to provide a control plane tool that can assist in the
other groups may also distribute working documents as Internet-Drafts. location of stranded resources by allowing adjacent Label-Switching
Routers (LSRs) to confirm data channel statuses and provide triggers
for notifying the management plane if any discrepancies are found.
As LMP is already used to verify data plane connectivity, it is
considered to be an appropriate candidate to support this feature.
Internet-Drafts are draft documents valid for a maximum of six months Status of This Memo
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 This is an Internet Standards Track document.
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at This document is a product of the Internet Engineering Task Force
http://www.ietf.org/shadow.html. (IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Abstract Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5818.
This document defines simple additions to the Link Management Copyright Notice
Protocol (LMP) to provide a control plane tool that can assist in
the location of stranded resources by allowing adjacent Label-
Switching Routers (LSRs) to confirm data channel statuses, and
provides triggers for notifying the management plane if any
discrepancies are found. As LMP is already used to verify data plane
connectivity, it is considered to be an appropriate candidate to
support this feature.
Conventions used in this document Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", This document is subject to BCP 78 and the IETF Trust's Legal
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this Provisions Relating to IETF Documents
document are to be interpreted as described in [RFC2119]. (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 Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction.................................................2 1. Introduction ....................................................3
2. Problem Explanation..........................................4 2. Specification of Requirements ...................................4
2.1. Mismatch Caused by Manual Configuration.................4 3. Problem Explanation .............................................4
2.2. Mismatch Caused by LSP Deletion.........................5 3.1. Mismatch Caused by Manual Configuration ....................4
2.3. Failed Resources........................................6 3.2. Mismatch Caused by LSP Deletion ............................5
3. Motivation...................................................6 3.3. Failed Resources ...........................................6
4. Extensions to LMP............................................7 4. Motivation ......................................................6
4.1. Confirm Data Channel Status Messages....................7 5. Extensions to LMP ...............................................7
4.1.1. ConfirmDataChannelStatus Messages..................7 5.1. Confirm Data Channel Status Messages .......................7
4.1.2. ConfirmDataChannelStatusAck Messages...............8 5.1.1. ConfirmDataChannelStatus Messages ...................8
4.1.3. ConfirmDataChannelStatusNack Messages..............8 5.1.2. ConfirmDataChannelStatusAck Messages ................8
4.2. Data Channel Status Subobject...........................9 5.1.3. ConfirmDataChannelStatusNack Messages ...............8
4.3. Message Construction...................................10 5.2. Data Channel Status Subobject ..............................9
4.4. Backward Compatibility.................................10 5.3. Message Construction ......................................10
5. Procedures..................................................10 5.4. Backward Compatibility ....................................10
6. Security Considerations.....................................12 6. Procedures .....................................................11
7. IANA Considerations.........................................12 7. Security Considerations ........................................12
7.1. LMP Message Types......................................12 8. IANA Considerations ............................................12
7.2. LMP Data Link Object Subobject.........................12 8.1. LMP Message Types .........................................12
8. Acknowledgments.............................................13 8.2. LMP Data Link Object Subobject ............................13
9. References..................................................13 8.3. LMP Error_Code Class Type .................................13
9.1. Normative References...................................13 9. Acknowledgments ................................................13
9.2. Informative References.................................13 10. References ....................................................13
10. Authors' Addresses.........................................14 10.1. Normative References .....................................13
11. Full Copyright Statement...................................15 10.2. Informative References ...................................14
12. Intellectual Property Statement............................15 Contributor's Address .............................................14
13. Disclaimer of Validity.....................................16
1. Introduction 1. Introduction
Generalized Multiprotocol Label Switching (GMPLS) networks are Generalized Multiprotocol Label Switching (GMPLS) networks are
constructed from Traffic Engineering (TE) links connecting Label constructed from Traffic Engineering (TE) links connecting Label
Switching Routers (LSRs). The TE links are constructed from a set of Switching Routers (LSRs). The TE links are constructed from a set of
data channels. In this context, a data channel corresponds to a data channels. In this context, a data channel corresponds to a
resource label in a non-packet technology (such as a timeslot or a resource label in a non-packet technology (such as a timeslot or a
lambda). lambda).
A data channel status mismatch exists if the LSR at one end of a TE A data channel status mismatch exists if the LSR at one end of a TE
link believes that the data channel is assigned to carry data, but link believes that the data channel is assigned to carry data, but
the LSR at the other end does not. The term "ready to carry data" the LSR at the other end does not. The term "ready to carry data"
means cross-connected or bound to an end-point for the receipt or means cross-connected or bound to an end-point for the receipt or
delivery of data. delivery of data.
Data channel mismatches cannot be detected from the TE information Data channel mismatches cannot be detected from the TE information
advertised by the routing protocols [RFC4203], [RFC5307]. The advertised by the routing protocols [RFC4203], [RFC5307]. The
existence of some data channel mismatch problems may be detected by existence of some data channel mismatch problems may be detected by a
a mismatch in the advertised bandwidths where bidirectional TE links mismatch in the advertised bandwidths where bidirectional TE links
and bidirectional services are in use, but where unidirectional and bidirectional services are in use. However, where unidirectional
services exist, or where multiple data channel mismatches occur, it services exist, or where multiple data channel mismatches occur, it
is not possible to detect such errors through the routing protocol- is not possible to detect such errors through the routing protocol-
advertised TE information. In any case, there is no mechanism to advertised TE information. In any case, there is no mechanism to
isolate the mismatches by determining which data channels are at isolate the mismatches by determining which data channels are at
fault. fault.
If a data channel mismatch exists, any attempt to use the data If a data channel mismatch exists, any attempt to use the data
channel for a new Label Switched Path (LSP) will fail. One end of channel for a new Label Switched Path (LSP) will fail. One end of
the TE link may attempt to assign the TE link for use, but the other the TE link may attempt to assign the TE link for use, but the other
end will report the data channel as unavailable when the control end will report the data channel as unavailable when the control
plane or management plane attempts to assign it to an LSP. plane or management plane attempts to assign it to an LSP.
Although such a situation can be resolved through the use of the Although such a situation can be resolved through the use of the
Acceptable Label Set object in GMPLS signaling [RFC3473], such a Acceptable Label Set object in GMPLS signaling [RFC3473], such a
procedure is inefficient since it may require an additional procedure is inefficient since it may require an additional signaling
signaling exchange for each LSP that is set up. When many LSPs are exchange for each LSP that is set up. When many LSPs are to be set
to be set up, and when there are many data channel mismatches, such up, and when there are many data channel mismatches, such
inefficiencies become significant. It is desirable to avoid the inefficiencies become significant. It is desirable to avoid the
additional signaling overhead, and to report the problems to the additional signaling overhead, and to report the problems to the
management plane so that they can be resolved to improve the management plane so that they can be resolved to improve the
efficiency of LSP setup. efficiency of LSP setup.
Correspondingly, such a mismatch situation may give rise to Correspondingly, such a mismatch situation may give rise to
misconnections in the data plane especially when LSPs are set up misconnections in the data plane, especially when LSPs are set up
using management plane operations. using management plane operations.
Resources (data channels) that are in a mismatched state are often Resources (data channels) that are in a mismatched state are often
described as "stranded resources". They are not in use for any LSP, described as "stranded resources". They are not in use for any LSP,
but they cannot be assigned for use by a new LSP because they appear but they cannot be assigned for use by a new LSP because they appear
to be in use. Although it is theoretically possible for management to be in use. Although it is theoretically possible for management
plane applications to audit all network resources to locate stranded plane applications to audit all network resources to locate stranded
resources and to release them, this process is rarely performed resources and to release them, this process is rarely performed
because of the difficulty of coordinating different Element because of the difficulty of coordinating different Element
Management Systems (EMSs), and the associated risks of accidentally Management Systems (EMSs) and the associated risks of accidentally
releasing in-use resources. It is desirable to have a control plane releasing in-use resources. It is desirable to have a control plane
mechanism that detects and reports stranded resources. mechanism that detects and reports stranded resources.
This document defines simple additions to the Link Management This document defines simple additions to the Link Management
Protocol (LMP) [RFC4204] to provide a control plane tool that can Protocol (LMP) [RFC4204] to provide a control plane tool that can
assist in the location of stranded resources by allowing adjacent assist in the location of stranded resources by allowing adjacent
LSRs to confirm data channel statuses, and provides triggers for LSRs to confirm data channel statuses and provide triggers for
notifying the management plane if any discrepancies are found. As LMP notifying the management plane if any discrepancies are found. As
is already used to verify data plane connectivity, it is considered LMP is already used to verify data plane connectivity, it is
to be an appropriate candidate to support this feature. considered to be an appropriate candidate to support this feature.
2. Problem Explanation 2. Specification of Requirements
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
3. Problem Explanation
Examples of data channel mismatches are described in the following Examples of data channel mismatches are described in the following
three scenarios. three scenarios.
In all of the scenarios, the specific channel resource of a data link In all of the scenarios, the specific channel resource of a data link
will be unavailable because of the data channel status mismatch, and will be unavailable because of the data channel status mismatch, and
this channel resource will be wasted. Furthermore, a data channel this channel resource will be wasted. Furthermore, a data channel
status mismatch may reduce the possibility of successful LSP status mismatch may reduce the possibility of successful LSP
establishment, because a data channel status mismatch may result in establishment, because a data channel status mismatch may result in
failure when establishing an LSP. failure when establishing an LSP.
So it is desirable to confirm the data channel statuses as early as So it is desirable to confirm the data channel statuses as early as
possible. possible.
2.1. Mismatch Caused by Manual Configuration 3.1. Mismatch Caused by Manual Configuration
The operator may have configured a cross-connect at only one end of The operator may have configured a cross-connect at only one end of a
a TE link using an EMS. The resource at one end of the data channel TE link using an EMS. The resource at one end of the data channel is
is allocated, but the corresponding resource is still available at allocated, but the corresponding resource is still available at the
the other end of the same data channel. In this case, the data other end of the same data channel. In this case, the data channel
channel may appear to be available for use by the control plane when may appear to be available for use by the control plane when viewed
viewed from one end of the TE link, but will be considered to be from one end of the TE link but, will be considered to be unavailable
unavailable by the other end of the TE link. Alternatively, the by the other end of the TE link. Alternatively, the available end of
available end of the data channel may be cross-connected by the the data channel may be cross-connected by the management plane, and
management plane and a misconnection may result from the fact that a misconnection may result from the fact that the other end of the
the other end of the data channel is already cross-connected. data channel is already cross-connected.
Figure 1 shows a data channel between nodes A and B. The resource at Figure 1 shows a data channel between nodes A and B. The resource at
A's end of the TE link is allocated through manual configuration, A's end of the TE link is allocated through manual configuration,
while the resource at B's end of the TE link available, so the data while the resource at B's end of the TE link is available, so the
channel status is mismatched. data channel status is mismatched.
allocated available allocated available
+-+------------+-+ +-+------------+-+
A |x| | | B A |x| | | B
+-+------------+-+ +-+------------+-+
data channel data channel
Figure 1. Mismatch caused by manual configuration
2.2. Mismatch Caused by LSP Deletion Figure 1. Mismatch Caused by Manual Configuration
3.2. Mismatch Caused by LSP Deletion
The channel status of a data link may become mismatched during the The channel status of a data link may become mismatched during the
LSP deletion process. If the LSP deletion process is aborted in the LSP deletion process. If the LSP deletion process is aborted in the
middle of the process (perhaps because of a temporary control plane middle of the process (perhaps because of a temporary control plane
failure), the cross-connect at the upstream node may be removed while failure), the cross-connect at the upstream node may be removed while
the downstream node still keeps its cross-connect, if the LSP the downstream node still keeps its cross-connect, if the LSP
deletion was initiated by the source node. deletion was initiated by the source node.
For example, in Figure 2 an LSP traverses nodes A, B, and C. Node B For example, in Figure 2, an LSP traverses nodes A, B, and C. Node B
resets abnormally when the LSP is being deleted. This results in the resets abnormally when the LSP is being deleted. This results in the
cross-connects of node A and C being removed, but the cross-connect cross-connects of nodes A and C being removed, but the cross-connect
of node B still being in use. So the data channel statuses between of node B still being in use. So, the data channel statuses between
nodes A and B, and between nodes B and C are both mismatched. nodes A and B, and between nodes B and C are both mismatched.
<---------LSP---------> <---------LSP--------->
+-+-------+-+-------+-+ +-+-------+-+-------+-+
| | |X| | | | | |X| | |
+-+-------+-+-------+-+ +-+-------+-+-------+-+
A B C A B C
Figure 2. Mismatch caused by LSP deletion
In [RFC2205] and [RFC3209], a soft state mechanism was defined to Figure 2. Mismatch Caused by LSP Deletion
prevent state discrepancies between LSRs. Resource ReserVation
In [RFC2205] and [RFC3209], a "soft state" mechanism was defined to
prevent state discrepancies between LSRs. Resource ReSerVation
Protocol-Traffic Engineering (RSVP-TE) restart processes ([RFC3473], Protocol-Traffic Engineering (RSVP-TE) restart processes ([RFC3473],
[RFC5063]) have been defined: adjacent LSRs may resynchronize their [RFC5063]) have been defined: adjacent LSRs may resynchronize their
control plane state to reinstate information about LSPs that have control plane state to reinstate information about LSPs that have
persisted in the data plane. Both mechanisms aim at keeping state persisted in the data plane. Both mechanisms aim at keeping state
consistency among nodes and allow LSRs to detect mismatched data consistency among nodes and allow LSRs to detect mismatched data
plane states. The data plane handling of such mismatched state can be plane states. The data plane handling of such mismatched states can
treated as a local policy decision. Some deployments may decide to be treated as a local policy decision. Some deployments may decide
automatically clean up the data plane state so it matches the control to automatically clean up the data plane state so it matches the
plane state, but others may choose to raise an alert to the control plane state, but others may choose to raise an alert to the
management plane and leave the data plane untouched just in case it management plane and leave the data plane untouched just in case it
is in use. is in use.
In such cases, data channel mismatches may arise after restart and In such cases, data channel mismatches may arise after restart and
might not be cleared up by the restart procedures. might not be cleared up by the restart procedures.
2.3. Failed Resources 3.3. Failed Resources
Even if the situation is not common, it might happen that a Even if the situation is not common, it might happen that a
termination point of a TE-link is seen as failed by one end, while termination point of a TE link is seen as failed by one end, while on
on the other end it is seen as OK. This problem may arise due to the other end it is seen as OK. This problem may arise due to some
some failure either in the hardware or in the status detection of failure either in the hardware or in the status detection of the
the termination point. termination point.
This mismatch in the termination point status can lead to failure This mismatch in the termination point status can lead to failure in
in case of bidirectional LSP set-up. the case of bidirectional LSP setup.
Good Failed Good Failed
+-+------------+-+ +-+------------+-+
A | | |X| B A | | |X| B
+-+------------+-+ +-+------------+-+
data channel data channel
Path Message with Upstream Label----> Path Message with Upstream Label---->
Figure 3. Mismatch caused by resource failure Figure 3. Mismatch Caused by Resource Failure
In this case upstream node chooses to use termination point A in In this case, the upstream node chooses to use termination point A in
order to receive traffic from downstream node. From the upstream order to receive traffic from the downstream node. From the upstream
node's point of view, the resource is available thus usable; however, node's point of view, the resource is available and thus usable;
in the downstream node, the corresponding termination point (resource however, in the downstream node, the corresponding termination point
B) is broken. This leads to a set-up failure. (resource B) is broken. This leads to a setup failure.
3. Motivation 4. Motivation
The requirement does not come from a lack in GMPLS specifications The requirement does not come from a lack in GMPLS specifications
themselves but rather from operational concerns because, in most themselves but rather from operational concerns because, in most
cases, GMPLS-controlled networks will co-exist with legacy networks cases, GMPLS-controlled networks will co-exist with legacy networks
and legacy procedures. and legacy procedures.
The protocol extensions defined in this document are intended to The protocol extensions defined in this document are intended to
detect data plane problems resulting from mis-use or mis- detect data plane problems resulting from misuse or misconfigurations
configurations triggered by user error, or resulting from failure to triggered by user error, or resulting from failure to clean up the
clean up the data plane after control plane disconnection. It is data plane after control plane disconnection. It is anticipated that
anticipated that human mistake is probably the major source of errors human mistakes are probably the major source of errors to deal with.
to deal with. It is not the intention to provide a protocol mechanism
to deal with broken implementations.
The procedures defined in this document are designed to be operated This document is not intened to provide a protocol mechanism to deal
on a periodic or on-demand basis. It is NOT RECOMMENDED that the with broken implementations.
The procedures defined in this document are designed to be performed
on a periodic or on-demand basis. It is NOT RECOMMENDED that the
procedures be used to provide a continuous and on-line monitoring procedures be used to provide a continuous and on-line monitoring
process. process.
As LMP is already used to verify data plane connectivity, it is As LMP is already used to verify data plane connectivity, it is
considered to be an appropriate candidate to support this feature. considered to be an appropriate candidate to support this feature.
4. Extensions to LMP 5. Extensions to LMP
A control plane tool to detect and isolate data channel mismatches is A control plane tool to detect and isolate data channel mismatches is
provided in this document by simple additions to the Link Management provided in this document by simple additions to the Link Management
Protocol (LMP) [RFC4204]. It can assist in the location of stranded Protocol (LMP) [RFC4204]. It can assist in the location of stranded
resources by allowing adjacent LSRs to confirm data channel statuses. resources by allowing adjacent LSRs to confirm data channel statuses.
Outline procedures are described in this section. More detailed Outline procedures are described in this section. More detailed
procedures are found in Section 5. procedures are found in Section 6.
The message formats in the sections that follow use Backus-Naur Form The message formats in the subsections that follow use Backus-Naur
(BNF) encoding as defined in [RFC5511]. Form (BNF) encoding as defined in [RFC5511].
4.1. Confirm Data Channel Status Messages 5.1. Confirm Data Channel Status Messages
Extensions to LMP to confirm a data channel status are described Extensions to LMP to confirm a data channel status are described
below. In order to confirm a data channel status, the new LMP below. In order to confirm a data channel status, the new LMP
messages are sent between adjacent nodes periodically or driven by messages are sent between adjacent nodes periodically or driven by
some event (such as an operator command, a configurable timer, or the some event (such as an operator command, a configurable timer, or the
rejection of an LSP setup message because of an unavailable resource). rejection of an LSP setup message because of an unavailable
The new LMP messages run over the control channel, encapsulated in resource). The new LMP messages run over the control channel,
UDP with an LMP port number and IP addressing as defined in Link encapsulated in UDP with an LMP port number and IP addressing as
Management Protocol (LMP) [RFC4204]. defined in "Link Management Protocol (LMP)" [RFC4204].
Three new messages are defined to check data channel status: Three new messages are defined to check data channel status:
ConfirmDataChannelStatus, ConfirmDataChannelStatusAck, ConfirmDataChannelStatus, ConfirmDataChannelStatusAck, and
ConfirmDataChannelStatusNack, which are described in detail in the ConfirmDataChannelStatusNack. These messages are described in detail
following sections. Message Type numbers are found in Section 7.1. in the following subsections. Message Type numbers are found in
Section 8.1.
4.1.1. ConfirmDataChannelStatus Messages 5.1.1. ConfirmDataChannelStatus Messages
The ConfirmDataChannelStatus message is used to tell the remote end The ConfirmDataChannelStatus message is used to provide the remote
of the data channel what the status of the local end of the data end of the data channel with the status of the local end of the data
channel is, and to ask the remote end to report its data channel. The channel and to ask the remote end to report its data channel. The
message may report on (and request information about) more than one message may report on (and request information about) more than one
data channel. data channel.
<ConfirmDataChannelStatus Message> ::= <Common Header> <ConfirmDataChannelStatus Message> ::= <Common Header>
<LOCAL_LINK_ID> <LOCAL_LINK_ID>
<MESSAGE_ID> <MESSAGE_ID>
<DATA_LINK>[<DATA_LINK>...] <DATA_LINK>[<DATA_LINK>...]
When a node receives the ConfirmDataChannelStatus message, and the When a node receives the ConfirmDataChannelStatus message, and the
data channel status confirmation procedure is supported at the node, data channel status confirmation procedure is supported at the node,
the node compares its own data channel statuses with all of the data the node compares its own data channel statuses with all of the data
channel statuses sent by the remote end in the channel statuses sent by the remote end in the
ConfirmDataChannelStatus message. If a data channel status mismatch ConfirmDataChannelStatus message. If a data channel status mismatch
is found, this mismatch result is expected to be reported to the is found, this mismatch result is expected to be reported to the
management plane for further action. Management plane reporting management plane for further action. Management plane reporting
procedures and actions are outside the scope of this document. procedures and actions are outside the scope of this document.
If the message is a Confirm Data Channel Status message, and the If the message is a Confirm Data Channel Status message, and the
Message_Id value is less than the largest Message_Id value previously MESSAGE_ID value is less than the largest MESSAGE_ID value previously
received from the sender for the specified TE link, then the message received from the sender for the specified TE link, then the message
SHOULD be treated as being out-of-order. SHOULD be treated as being out-of-order.
4.1.2. ConfirmDataChannelStatusAck Messages 5.1.2. ConfirmDataChannelStatusAck Messages
The ConfirmDataChannelStatusAck message is sent back to the node The ConfirmDataChannelStatusAck message is sent back to the node that
which originated the ConfirmDataChannelStatus message to return the originated the ConfirmDataChannelStatus message to return the
requested data channel statuses. requested data channel statuses.
When the ConfirmDataChannelStatusAck message is received, the node When the ConfirmDataChannelStatusAck message is received, the node
compares the received data channel statuses at the remote end with compares the received data channel statuses at the remote end with
those at the local end (the same operation as performed by the those at the local end (the same operation as performed by the
receiver of the ConfirmDataChannelStatus message). If a data channel receiver of the ConfirmDataChannelStatus message). If a data channel
status mismatch is found, the mismatch result is expected to be status mismatch is found, the mismatch result is expected to be
reported to the management plane for further action. reported to the management plane for further action.
<ConfirmDataChannelStatusAck Message> ::= <Common Header> <ConfirmDataChannelStatusAck Message> ::= <Common Header>
<MESSAGE_ID_ACK> <MESSAGE_ID_ACK>
<DATA_LINK>[<DATA_LINK>...] <DATA_LINK>[<DATA_LINK>...]
The contents of the MESSAGE_ID_ACK objects MUST be obtained from the The contents of the MESSAGE_ID_ACK objects MUST be obtained from the
ConfirmDataChannelStatus message being acknowledged. ConfirmDataChannelStatus message being acknowledged.
Note that the ConfirmDataChannelStatusAck message is used both when Note that the ConfirmDataChannelStatusAck message is used both when
the data channel statuses match and when they do not match. the data channel statuses match and when they do not match.
4.1.3. ConfirmDataChannelStatusNack Messages 5.1.3. ConfirmDataChannelStatusNack Messages
When a node receives the ConfirmDataChannelStatus message, if the When a node receives the ConfirmDataChannelStatus message, if the
data channel status confirmation procedure is not supported but the data channel status confirmation procedure is not supported but the
message is recognized, a ConfirmDataChannelStatusNack message message is recognized, a ConfirmDataChannelStatusNack message
containing an ERROR_CODE indicating "Channel Status Confirmation containing an ERROR_CODE indicating "Channel Status Confirmation
Procedure not supported" MUST be sent. Procedure not supported" MUST be sent.
If the data channel status confirmation procedure is supported, but If the data channel status confirmation procedure is supported, but
the node is unable to begin the procedure, a the node is unable to begin the procedure, a
ConfirmDataChannelStatusNack message containing an ERROR_CODE ConfirmDataChannelStatusNack message containing an ERROR_CODE
indicating "Unwilling to Confirm" MUST be sent. If a indicating "Unwilling to Confirm" MUST be sent. If a
ConfirmDataChannelStatusNack message is received with such an ConfirmDataChannelStatusNack message is received with such an
ERROR_CODE, the node which originated the ConfirmDataChannelStatus ERROR_CODE, the node that originated the ConfirmDataChannelStatus
message MAY schedule the ConfirmDataChannelStatus message message MAY schedule the ConfirmDataChannelStatus message
retransmission after a configured time. A default value of 10 minutes retransmission after a configured time. A default value of
is suggested for this timer. 10 minutes is suggested for this timer.
<ConfirmDataChannelStatusNack Message> ::= <Common Header> <ConfirmDataChannelStatusNack Message> ::= <Common Header>
[<LOCAL_LINK_ID>] [<LOCAL_LINK_ID>]
<MESSAGE_ID_ACK> <MESSAGE_ID_ACK>
<ERROR_CODE> <ERROR_CODE>
The contents of the MESSAGE_ID_ACK objects MUST be obtained from the The contents of the MESSAGE_ID_ACK objects MUST be obtained from the
ConfirmDataChannelStatus message being rejected. ConfirmDataChannelStatus message being rejected.
4.2. Data Channel Status Subobject The ERROR_CODE object in this message has a new Class Type (see
Section 8.3), but is formed as the ERROR_CODE object defined in
[RFC4204]. The following Error Codes are defined:
0x01 = Channel Status Confirmation Procedure not supported
0x02 = Unwilling to Confirm
5.2. Data Channel Status Subobject
A new Data Channel Status subobject type is introduced to the DATA A new Data Channel Status subobject type is introduced to the DATA
LINK object to hold the data channel status and Data Channel LINK object to hold the Data Channel Status and Data Channel ID.
Identification.
See Section 7.2 for the Subobject Type value. See Section 8.2 for the Subobject Type value.
0 1 2 3 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 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 | Length | Data Channel Status | | Type | Length | Data Channel Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
// Data Channel ID // // Data Channel ID //
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Channel Status: Data Channel Status:
This is a series of bit flags to indicate the status of the data This is a series of bit flags to indicate the status of the data
channel. The following values are defined. channel. The following values are defined.
0x0000 : The channel is available/free. 0x0000 : The channel is available/free.
0x0001 : The channel is unavailable/in-use. 0x0001 : The channel is unavailable/in-use.
Data Channel ID Data Channel ID
This identifies the data channel. The length of this field can be This identifies the data channel. The length of this field can be
deduced from the Length field in the subobject. Note that all deduced from the Length field in the subobject. Note that all
subobjects must be padded to a four byte boundary with trailing zeros. subobjects must be padded to a four-byte boundary with trailing
zeros.
If such padding is required, the Length field MUST indicate the If such padding is required, the Length field MUST indicate the
length of the subobject up to, but not including, the first byte of length of the subobject up to, but not including, the first byte of
padding. Thus, the amount of padding is deduced and not represented padding. Thus, the amount of padding is deduced and not represented
in the Length field. in the Length field.
Note that the Data Channel ID is given in the context of the sender Note that the Data Channel ID is given in the context of the sender
of the ConfirmChannelStatus message. of the ConfirmChannelStatus message.
The data-channel ID must be encoded as a label value. Based on the The Data Channel ID must be encoded as a label value. Based on the
type of signal e.g. SONET/SDH, Lambda etc. the encoding methodology type of signal (e.g., Synchronous Optical Network/Synchronous Digital
used will be different. For SONET/SDH the label value is encoded as Hierarchy (SONET/SDH), Lambda, etc.), the encoding methodology
used will be different. For SONET/SDH, the label value is encoded as
per [RFC4606]. per [RFC4606].
4.3. Message Construction 5.3. Message Construction
Data_Link Class is included in ConfirmDataChannelStatus and Data_Link Class (as defined in Section 13.12 of [RFC4204]) is
ConfirmDataChannelStatusAck messages, which is defined in section included in ConfirmDataChannelStatus and ConfirmDataChannelStatusAck
13.12 in [RFC4204]. messages.
The status of the TE link end MUST be carried by the Data Channel The status of the TE link end MUST be carried by the Data Channel
Status subobject which is defined in section 4.2 of this document. Status subobject, which is defined in Section 5.2 of this document.
The new subobject MUST be part of Data_Link Class. The new subobject MUST be part of Data_Link Class.
In the case of SDH/SONET, DATA Channel ID in the new subobject SHOULD In the case of SONET/SDH, the Data Channel ID in the new subobject
be used to identify each timeslot of the data link. SHOULD be used to identify each timeslot of the data link.
4.4. Backward Compatibility 5.4. Backward Compatibility
Some nodes running in the network may only support the LMP Message Some nodes running in the network might only support the LMP Message
Types, which are already defined in [RFC4204]. The three new types of Types, which are already defined in [RFC4204]. The three new types
LMP message defined in this document can not be recognized by these of LMP messages defined in this document cannot be recognized by
nodes. The unknown message behavior is not being specified in these nodes. The behavior of an LMP node that receives an unknown
[RFC4204], it's suggested to discard the unknown message silently. message is not specified in [RFC4204] and will be clarified in a
The mechanism defined in this document presumes a certain non- separate document.
standard behavior of existing/non-document supporting nodes. To use
this mechanism all nodes MUST have the extensions described in this
document for compatibility.
5. Procedures Since the behavior of legacy nodes must be assumed to be unknown,
this document assumes that a deployment intended to support the
function described in this document will consist completely of nodes
that support the protocol extensions also described in this document.
Adjacent nodes MAY send data channel status confirmation related LMP In the future, it may be the case that LMP will be extended to allow
messages. Periodical timers or some other events requesting the function support to be detected. In that case, it may become
possible to deploy this function in a mixed environment.
6. Procedures
Adjacent nodes MAY send data channel status confirmation-related LMP
messages. Periodical timers or some other events requesting the
confirmation of channel status for the data link may trigger these confirmation of channel status for the data link may trigger these
messages. It's a local policy decision to start the data channel messages. It's a local policy decision to start the data channel
status confirmation process. The procedure is described below: status confirmation process. The procedure is described below:
. Initially, the SENDER constructs a ConfirmDataChannelStatus . Initially, the SENDER constructs a ConfirmDataChannelStatus
message which MUST contain one or more DATA_LINK objects. message that MUST contain one or more DATA_LINK objects. The
DATA_LINK object is defined in [RFC4204]. Each DATA_LINK object DATA_LINK object is defined in [RFC4204]. Each DATA_LINK object
MUST contain one or more Data Channel Status subobjects. The Data MUST contain one or more Data Channel Status subobjects. The Data
Channel ID field in the Data Channel Status subobject MUST Channel ID field in the Data Channel Status subobject MUST
indicate which data channel needs to be confirmed, and MUST report indicate which data channel needs to be confirmed, and MUST report
the data channel status at the SENDER. The the data channel status at the SENDER. The
ConfirmDataChannelStatus message is sent to the RECEIVER. ConfirmDataChannelStatus message is sent to the RECEIVER.
. Upon reception of a ConfirmDataChannelStatus message, the RECEIVER . Upon receipt of a ConfirmDataChannelStatus message, the RECEIVER
MUST extract the data channel statuses from the MUST extract the data channel statuses from the
ConfirmDataChannelStatus message, and SHOULD compare these with ConfirmDataChannelStatus message and SHOULD compare these with its
its data channel statuses for the reported data channels. If a data channel statuses for the reported data channels. If a data
data channel status mismatch is found, the mismatch result SHOULD channel status mismatch is found, the mismatch result SHOULD be
be reported to the management plane for further action. The reported to the management plane for further action. The RECEIVER
RECEIVER also SHOULD send the ConfirmDataChannelStatusAck message also SHOULD send the ConfirmDataChannelStatusAck message, which
which MUST carry all the local end statuses of the requested data MUST carry all the local end statuses of the requested data
channels to the SENDER. channels to the SENDER.
. If the RECEIVER is not able to support or to begin the . If the RECEIVER is not able to support or to begin the
confirmation procedure, the ConfirmDataChannelStatusNack message confirmation procedure, the RECEIVER MUST send a
MUST be responded with the ERROR_CODE which indicates the reason ConfirmDataChannelStatusNack message containing the ERROR_CODE
of rejection. that indicates the reason for rejection.
. Upon reception of a ConfirmDataChannelStatusAck message, the . Upon receipt of a ConfirmDataChannelStatusAck message, the SENDER
SENDER MUST compare the received data channel statuses at the MUST compare the received data channel statuses at the remote end
remote end with the data channel statuses at the local end. If a with the data channel statuses at the local end. If a data
data channel status mismatch is found, the mismatch result SHOULD channel status mismatch is found, the mismatch result SHOULD be
be reported to the management plane for further action. reported to the management plane for further action.
The data channel status mismatch issue identified by LMP may be The data channel status mismatch issue identified by LMP may be
automatically resolved by RSVP restart. For example, the restarting automatically resolved by RSVP restart. For example, the restarting
node may also have damaged its data plane. This leaves the data node may also have damaged its data plane. This leaves the data
channels mismatched. But RSVP restart will re-install the data plane channels mismatched. However, RSVP restart will re-install the data
state in the restarting node. The issue may also be resolved via RSVP plane state in the restarting node. The issue may also be resolved
soft state timeout. via RSVP soft state timeout.
If the ConfirmDataChannelStatus message is not recognized by the If the ConfirmDataChannelStatus message is not recognized by the
RECEIVER, the RECEIVER ignores this message, and will not send out an RECEIVER, the RECEIVER ignores this message and will not send out an
acknowledgment message to the SENDER. acknowledgment message to the SENDER.
Due to message loss problem, the SENDER may not be able to receive Due to the message loss problem, the SENDER may not be able to
the acknowledgment message. receive the acknowledgment message.
ConfirmDataChannelStatus SHOULD be sent using LMP [RFC4204] reliable ConfirmDataChannelStatus SHOULD be sent using LMP [RFC4204] reliable
transmission mechanisms. If after the retry limit is reached, a transmission mechanisms. If, after the retry limit is reached, a
ConfirmDataChannelStatusAck message or a ConfirmDataChannelStatusNack ConfirmDataChannelStatusAck message or a ConfirmDataChannelStatusNack
message is not received by the SENDER, the SENDER SHOULD terminate message is not received by the SENDER, the SENDER SHOULD terminate
the data channel confirmation procedure. the data channel confirmation procedure and SHOULD raise an alert to
the management plane.
6. Security Considerations 7. Security Considerations
[RFC4204] describes how LMP messages between peers can be secured, [RFC4204] describes how LMP messages between peers can be secured,
and these measures are equally applicable to the new messages defined and these measures are equally applicable to the new messages defined
in this document. in this document.
The operation of the procedures described in this document does not The operation of the procedures described in this document does not
of themselves constitute a security risk since they do not cause any of itself constitute a security risk because it does not cause any
change in network state. It would be possible, if the messages were change in network state. It would be possible, if the messages were
intercepted or spoofed to cause bogus alerts in the management plane intercepted or spoofed, to cause bogus alerts in the management
and so the use of the LMP security measures are RECOMMENDED. plane, and so the use of LMP security measures described in [RFC4204]
is RECOMMENDED.
Note that operating the procedures described in this document may Note that performing the procedures described in this document may
provide a useful additional security measure to verify that data provide a useful additional security measure to verify that data
channels have not been illicitly modified. channels have not been illicitly modified.
7. IANA Considerations 8. IANA Considerations
7.1. LMP Message Types 8.1. LMP Message Types
IANA maintains the "Link Management Protocol (LMP)" registry which IANA maintains the "Link Management Protocol (LMP)" registry, which
has a subregistry called "LMP Message Type". IANA is requested to has a subregistry called "LMP Message Type". IANA has made the
make three new allocations from this registry as follows. The message following three new allocations from this registry.
type values are suggested and to be confirmed by IANA.
Value Description Value Description
------ --------------------------------- ------ ---------------------------------
32 ConfirmDataChannelStatus 32 ConfirmDataChannelStatus
33 ConfirmDataChannelStatusAck 33 ConfirmDataChannelStatusAck
34 ConfirmDataChannelStatusNack 34 ConfirmDataChannelStatusNack
7.2. LMP Data Link Object Subobject 8.2. LMP Data Link Object Subobject
IANA maintains the "Link Management Protocol (LMP)" registry which IANA maintains the "Link Management Protocol (LMP)" registry, which
has a subregistry called "LMP Object Class name space and Class type has a subregistry called "LMP Object Class name space and Class type
(C-Type)". This subregistry has an entry for the DATA_LINK object, (C-Type)". This subregistry has an entry for the DATA_LINK object,
and there is a further embedded registry called "DATA_LINK Sub-object and there is a further embedded registry called "DATA_LINK Sub-object
Class name space". IANA is requested to make the following allocation Class name space". IANA has made the following allocation from this
from this embedded registry. The value shown is suggested and to be embedded registry.
confirmed by IANA.
Value Description Value Description
------ --------------------------------- ------ ---------------------------------
9 Data Channel Status 9 Data Channel Status
8. Acknowledgments 8.3. LMP Error_Code Class Type
We would like to thank Adrian Farrel, Dimitri Papadimitriou, Lou IANA maintains the "Link Management Protocol (LMP)" registry, which
Berger for their useful comments. has a subregistry called "LMP Object Class name space and Class type
(C-Type)". This subregistry has an entry for the ERROR_CODE object.
IANA has allocated the following new value for an ERROR_CODE class
type.
9. References C-Type Description Reference
------ ---------------------------- ---------
4 ConfirmDataChannelStatusNack [This RFC]
9.1. Normative References 9. Acknowledgments
The authors would like to thank Adrian Farrel, Dimitri Papadimitriou,
and Lou Berger for their useful comments.
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4204] J. Lang, Ed., "Link Management Protocol (LMP)", RFC 4204, [RFC4204] Lang, J., Ed., "Link Management Protocol (LMP)",
October 2005. RFC 4204, October 2005.
[RFC5511] A. Farrel, Ed., "Routing Backus-Naur Form (RBNF): A [RFC5511] Farrel, A., Ed., "Routing Backus-Naur Form (RBNF):
Syntax Used to Form Encoding Rules in Various Routing A Syntax Used to Form Encoding Rules in Various Routing
Protocol Specifications", RFC 5511, April 2009. Protocol Specifications", RFC 5511, April 2009.
9.2. Informative References 10.2. Informative References
[RFC2205] R. Braden, Ed., "Resource ReSerVation Protocol (RSVP) -- [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and
Version 1 Functional Specification", RFC 2205, September S. Jamin, "Resource ReSerVation Protocol (RSVP) --
1997 Version 1 Functional Specification", RFC 2205,
September 1997.
[RFC3209] D. Awduche, L. Berger, D. Gan, T. Li, V. Srinivasan, G. [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
RFC 3209, December 2001 Tunnels", RFC 3209, December 2001.
[RFC3473] L. Berger, Ed., "Generalized Multi-Protocol Label [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Switching (GMPLS) Signaling Resource ReserVation
Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC Protocol-Traffic Engineering (RSVP-TE) Extensions",
3473, January 2003 RFC 3473, January 2003.
[RFC5063] A. Satyanarayana, R. Rahman, "Extensions to GMPLS RSVP [RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions
Graceful Restart", RFC 5063, September 2007 in Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 4203, October 2005.
[RFC4203] K. Kompella, Ed., "OSPF Extensions in Support of [RFC4606] Mannie, E. and D. Papadimitriou, "Generalized Multi-
Generalized Multi-Protocol Label Switching (GMPLS)", RFC Protocol Label Switching (GMPLS) Extensions for
4203, October 2005 Synchronous Optical Network (SONET) and Synchronous
Digital Hierarchy (SDH) Control", RFC 4606, August 2006.
[RFC4606] E. Mannie, Ed., "Generalized Multi-Protocol Label [RFC5063] Satyanarayana, A., Ed., and R. Rahman, Ed., "Extensions
Switching (GMPLS) Extensions for Synchronous Optical to GMPLS Resource Reservation Protocol (RSVP) Graceful
Network (SONET) and Synchronous Digital Hierarchy (SDH) Restart", RFC 5063, October 2007.
Control", RFC 4606, August 2006
[RFC5307] K. Kompella, Ed., "IS-IS Extensions in Support of [RFC5307] Kompella, K., Ed., and Y. Rekhter, Ed., "IS-IS Extensions
Generalized Multi-Protocol Label Switching (GMPLS)", RFC in Support of Generalized Multi-Protocol Label Switching
5307, October 2008 (GMPLS)", RFC 5307, October 2008.
10. Authors' Addresses Contributor's Address
Dan Li Fatai Zhang
Huawei Technologies Huawei Technologies
F3-5-B R&D Center, Huawei Base, F3-5-B R&D Center, Huawei Base
Shenzhen 518129 China Shenzhen 518129 China
Phone: +86 755-289-70230 Phone: +86 755-289-72912
Email: danli@huawei.com EMail: zhangfatai@huawei.com
Huiying Xu Authors' Addresses
Dan Li
Huawei Technologies Huawei Technologies
F3-5-B R&D Center, Huawei Base, F3-5-B R&D Center, Huawei Base
Shenzhen 518129 China Shenzhen 518129 China
Phone: +86 755-289-72910 Phone: +86 755-289-70230
Email: xuhuiying@huawei.com EMail: danli@huawei.com
Fatai Zhang Huiying Xu
Huawei Technologies Huawei Technologies
F3-5-B R&D Center, Huawei Base, F3-5-B R&D Center, Huawei Base
Shenzhen 518129 China Shenzhen 518129 China
Phone: +86 755-289-72912 Phone: +86 755-289-72910
Email: zhangfatai@huawei.com EMail: xuhuiying@huawei.com
Snigdho C. Bardalai Snigdho C. Bardalai
Fujitsu Network Communications Fujitsu Network Communications
2801 Telecom Parkway, 2801 Telecom Parkway
Richardson, Texas 75082, USA Richardson, Texas 75082, USA
Phone: +1 972 479 2951 Phone: +1 972 479 2951
Email: snigdho.bardalai@us.fujitsu.com EMail: snigdho.bardalai@us.fujitsu.com
Julien Meuric Julien Meuric
France Telecom Orange Labs France Telecom Orange Labs
2, avenue Pierre Marzin 2, avenue Pierre Marzin
22307 Lannion Cedex, France 22307 Lannion Cedex, France
Phone: +33 2 96 05 28 28 Phone: +33 2 96 05 28 28
Email: julien.meuric@orange-ftgroup.com EMail: julien.meuric@orange-ftgroup.com
Diego Caviglia Diego Caviglia
Ericsson Ericsson
Via A. Negrone 1/A 16153 Via A. Negrone 1/A 16153
Genoa Italy Genoa Italy
Phone: +39 010 600 3736 Phone: +39 010 600 3736
Email: diego.caviglia@ericsson.com EMail: diego.caviglia@ericsson.com
11. Full Copyright Statement
Copyright (c) 2009 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 in effect on the date of
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Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.
This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November 10,
2008. The person(s) controlling the copyright in some of this
material may not have granted the IETF Trust the right to allow
modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other
than English.
12. Intellectual Property Statement
The IETF Trust takes no position regarding the validity or scope of
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Copies of Intellectual Property disclosures made to the IETF
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