rtgwg N. Kumar
Internet-Draft C. Pignataro
Intended status: Informational D. Kumar
Expires: January 8, 2017 Cisco Systems, Inc.
G. Mirsky
Ericsson
M. Chen
Huawei Technologies
E. Nordmark
Arista Networks
S. Pallagatti
Juniper Networks
D. Mozes
Mellanox Technologies Ltd
July 7, 2016
Overlay OAM Requirements
draft-ooamdt-rtgwg-ooam-requirement-01
Abstract
This document describes a list of functional requirements for
Operations Administration and Maintenance (OAM) in various Overlay
and Service networks like Service Function Chaining (SFC), Bit Index
Explicit Replication (BIER), Network Virtualization over Layer 3
(NVO3).
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). Note that other groups may also distribute
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Drafts is at http://datatracker.ietf.org/drafts/current/.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 8, 2017.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements notation . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Detailed Requirement List . . . . . . . . . . . . . . . . . . 4
4.1. Fault Management . . . . . . . . . . . . . . . . . . . . 5
4.1.1. Pro-active Fault Management . . . . . . . . . . . . . 5
4.1.2. On-demand Fault Management . . . . . . . . . . . . . 5
4.2. Performance Management . . . . . . . . . . . . . . . . . 6
4.3. Alarm Indication Suppression . . . . . . . . . . . . . . 7
4.4. Overlay Network Resiliency . . . . . . . . . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
We have witnessed and participated in design of new paradigms in the
networking that are aimed to address network virtualization, service
function chaining, and multicast services. New paradigms require new
architectural concepts, principles and components. [RFC7365] defines
a framework for Data Center Network Virtualization over Layer 3
(NVO3). [RFC7665] describes the architecture for creating and
maintaining Service Function Chains (SFCs) in a network.
[I-D.ietf-bier-architecture] defines a stateless multicast
architecture for optimal multicast packet forwarding using "Bit Index
Explicit Replication" (BIER). These frameworks are defined in a
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flexible manner that they are transport agnostic and may be deployed
on various underlay networks such as IPv4, IPv6 and MPLS.
The above mentioned new architectural concepts and principles have
been combined into new network layers with distinct encapsulation
headers. For example, [I-D.ietf-sfc-nsh] defines an encapsulation
header as Network Service Header (NSH) to realize Service Function
Path. While [RFC7348] (VxLAN) and [RFC7637] (NVGRE) are different
encapsulation header proposed for NVO3, [I-D.ietf-nvo3-vxlan-gpe]
extends VxLAN further to be used for Service Function Chain (SFC).
Similarly, [I-D.ietf-bier-mpls-encapsulation] defines the BIER
encapsulation header over MPLS network and
[I-D.xu-bier-encapsulation] describes the BIER encapsulation header
over IP network.
Introduction of the new Overlay networks, sets forth new Operations,
Administration and Maintenance (OAM) requirements that can be
addressed by enhancing the existing toolset or developing new
protocols. For example, [I-D.ietf-sfc-oam-framework] defines the
framework for SFC OAM, [I-D.nordmark-nvo3-transcending-traceroute]
proposes a way to perform traceroute in NVO3 networks and
[I-D.kumarzheng-bier-ping] proposes on-demand connectivity
verification and fault isolation procedure (Ping and Trace) on BIER
network.
The goal of this document is to identify and list the OAM
requirements commonly applicable to new Overlay networks which can
further be used to analyze the existing OAM tools. The identified
gaps can be addressed, either through enhancing existing OAM tools
and if necessary, constructing new OAM tools, that can be used as a
common unified OAM toolset to support and perform various OAM
functions including proactive and on-demand path monitoring and
service validation on the new Overlay network.
2. Requirements notation
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. Terminology
ECMP: Equal Cost Multipath
SFC: Service Function Chaining
BIER: Bit Index Explicit Replication
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NVO3: Network Virtualization over L3
OAM: Operations, Administration and Maintenance
MPLS: Multiprotocol Label Switching
VxLAN: Virtual Extensible Local Area Network
NVGRE: Network Virtualization Using Generic Routing Encapsulation
Centralized Controller: An external standalone or virtual entity with
topology awareness and with an ability to interact with network
devices for OAM functionality.
Overlay nodes: Network nodes participating in the Overlay network.
Underlay Network or Underlay Layer: The network that provides
connectivity between the Overlay nodes. MPLS network providing LSP
connectivity between BIER nodes is an example for underlay layer.
Overlay Network or Overlay Layer: A network layer that is built on
top another network layer. VxLAN-GPE over IP network is an example
for Overlay layer.
4. Detailed Requirement List
This section lists the OAM requirement for different Overlay
networks. The below listed requirement MUST be supported with any
underlay transport network:
REQ#1: The listed requirements MUST be supported with any type of
transport layer over which the overlay network can be
realized.
REQ#2: It MUST be possible to initialize Overlay OAM between any
node towards any node(s) in the overlay network.
REQ#3: It SHOULD be possible to initialize an Overlay OAM from a
centralized controller.
REQ#4: Overlay OAM MUST support proactive and on-demand OAM
monitoring and measurement methods.
REQ#5: Overlay OAM MUST support unidirectional OAM methods for
continuity check, connectivity verification and performance
measurement.
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REQ#6: Overlay OAM packets SHOULD be fate sharing with data traffic,
i.e. in-band with the monitored traffic, i.e. follow exactly
the same overlay and transport path as data plane traffic,
in forward direction, i.e. from ingress toward egress end
point(s) of the OAM test.
REQ#7: Overlay OAM MUST support bi-directional OAM methods. Such
OAM methods MAY combine in-band monitoring or measurement in
forward direction and out-of-band notification in the
reverse direction, i.e. from egress to ingress end point of
the OAM test.
REQ#8: Overlay OAM MUST support Path Maximum Transmission Unit (MTU)
Discovery from the overlay layer over any transport layer.
4.1. Fault Management
4.1.1. Pro-active Fault Management
Availability, not as performance metric, is understood as ability to
reach the node, i.e. the fact that path between ingress and egress
does exist. Such OAM mechanism also referred as Continuity Check.
REQ#9: Overlay OAM MUST support pro-active monitoring of any virtual
node availability in the given overlay network.
REQ#10: Overlay OAM MUST support Remote Defect Indication (RDI)
notification by egress to the ingress, i.e. source of
continuity checking.
REQ#11: Overlay OAM MUST support connectivity verification.
Definition of mis-connectivity defect entry and exit
criteria are outside the scope of this document.
4.1.2. On-demand Fault Management
REQ#12: Overlay OAM MUST support fault localization of Loss of
Continuity check at Overlay layer.
REQ#13: Overlay OAM MAY support fault localization of Loss of
Continuity check at transport layer.
REQ#14: Overlay OAM MUST support tracing path in overlay network
through the overlay nodes.
REQ#15: Overlay OAM MAY support tracing path in underlay network
connecting overlay border nodes.
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REQ#16: Overlay OAM MAY support verification of the mapping between
its data plane state and client layer services.
REQ#17: Overlay OAM MUST have the ability to discover and exercise
equal cost multipath (ECMP) paths in its underlay network.
REQ#18: Overlay OAM MUST be able to trigger on-demand FM with
responses being directed towards initiator of such proxy
request.
4.2. Performance Management
Section 3.4 and Section 3.5 of [RFC7799] defines the definition for
Active and Passive mode of Performance Measurement (PM) methods.
This section lists the requirements for both active and passive PM
methods. Passive PM is a measurement method that should not modify
the actual data packet processing behavior on underlay and overlay
network. Accordingly, it should be supported by the Overlay nodes.
REQ#19: Overlay OAM MUST support active one-way packet delay
measurement.
REQ#20: Overlay OAM MUST support passive one-way packet delay
measurement.
REQ#21: Overlay OAM MUST support active two-way packet delay
measurement.
REQ#22: Overlay OAM MUST support packet delay variation measurement.
REQ#23: Overlay OAM MUST support active end to end packet loss
measurement.
REQ#24: Overlay OAM MUST support passive end to end packet loss
measurement.
REQ#25: Overlay OAM SHOULD support active per-segment packet delay
measurement.
REQ#26: Overlay OAM SHOULD support passive per-segment packet delay
measurement.
REQ#27: Overlay OAM SHOULD support active per-segment packet loss
measurement.
REQ#28: Overlay OAM SHOULD support passive per-segment packet loss
measurement.
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REQ#29: Overlay OAM MUST support delivered packet throughput
measurement.
4.3. Alarm Indication Suppression
REQ#30: Overlay OAM MUST support defect notification mechanism, like
Alarm Indication Signal.
REQ#31: Any virtual node in the given overlay network MAY originate a
defect notification addressed to any node in that network.
4.4. Overlay Network Resiliency
REQ#32: Overlay OAM MUST support methods to enable survivability of
an overlay network. These recovery methods MAY use
protection switching and restoration.
5. IANA Considerations
This document does not propose any IANA consideration.
6. Security Considerations
This document list the OAM requirement for various Overlay
encapsulations and may have security implications. For example, if
proactive FM is required, the security implication is that a passive
eavesdropper can know when the session is down. Or, proactive FM may
be used either to launch DoS or to highjack session and impact state,
e.g. cause protection switchover. These security implications are
natural results of the requirements, and do not depend on the
particular implementation. Whether existing security mechanisms of
existing protocols proposed to be re-used in OAM for overlay networks
are adequate or require enhancements is for further study. New OAM
protocols for overlay networks must consider their security mechanism
to on per-solution basis.
7. Acknowledgement
The Authors would like to thank Ron Bonico, Tal Mizrahi, Alia Atlas
and Saumya Dikshit for their review and comments.
8. References
8.1. Normative References
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[I-D.ietf-bier-architecture]
Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and
S. Aldrin, "Multicast using Bit Index Explicit
Replication", draft-ietf-bier-architecture-03 (work in
progress), January 2016.
[I-D.ietf-bier-mpls-encapsulation]
Wijnands, I., Rosen, E., Dolganow, A., Tantsura, J., and
S. Aldrin, "Encapsulation for Bit Index Explicit
Replication in MPLS Networks", draft-ietf-bier-mpls-
encapsulation-04 (work in progress), April 2016.
[I-D.ietf-nvo3-vxlan-gpe]
Kreeger, L. and U. Elzur, "Generic Protocol Extension for
VXLAN", draft-ietf-nvo3-vxlan-gpe-02 (work in progress),
April 2016.
[I-D.ietf-sfc-nsh]
Quinn, P. and U. Elzur, "Network Service Header", draft-
ietf-sfc-nsh-05 (work in progress), May 2016.
[I-D.ietf-sfc-oam-framework]
Aldrin, S., Krishnan, R., Akiya, N., Pignataro, C., and A.
Ghanwani, "Service Function Chaining Operation,
Administration and Maintenance Framework", draft-ietf-sfc-
oam-framework-01 (work in progress), February 2016.
[I-D.kumarzheng-bier-ping]
Kumar, N., Pignataro, C., Akiya, N., Zheng, L., Chen, M.,
and G. Mirsky, "BIER Ping and Trace", draft-kumarzheng-
bier-ping-03 (work in progress), July 2016.
[I-D.nordmark-nvo3-transcending-traceroute]
Nordmark, E., Appanna, C., and A. Lo, "Layer-Transcending
Traceroute for Overlay Networks like VXLAN", draft-
nordmark-nvo3-transcending-traceroute-02 (work in
progress), March 2016.
[I-D.xu-bier-encapsulation]
Xu, X., somasundaram.s@alcatel-lucent.com, s., Jacquenet,
C., and R. Raszuk, "A Transport-Independent Bit Index
Explicit Replication (BIER) Encapsulation Header", draft-
xu-bier-encapsulation-05 (work in progress), June 2016.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
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[RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
eXtensible Local Area Network (VXLAN): A Framework for
Overlaying Virtualized Layer 2 Networks over Layer 3
Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014,
<http://www.rfc-editor.org/info/rfc7348>.
[RFC7365] Lasserre, M., Balus, F., Morin, T., Bitar, N., and Y.
Rekhter, "Framework for Data Center (DC) Network
Virtualization", RFC 7365, DOI 10.17487/RFC7365, October
2014, <http://www.rfc-editor.org/info/rfc7365>.
[RFC7637] Garg, P., Ed. and Y. Wang, Ed., "NVGRE: Network
Virtualization Using Generic Routing Encapsulation",
RFC 7637, DOI 10.17487/RFC7637, September 2015,
<http://www.rfc-editor.org/info/rfc7637>.
[RFC7665] Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
Chaining (SFC) Architecture", RFC 7665,
DOI 10.17487/RFC7665, October 2015,
<http://www.rfc-editor.org/info/rfc7665>.
[RFC7799] Morton, A., "Active and Passive Metrics and Methods (with
Hybrid Types In-Between)", RFC 7799, DOI 10.17487/RFC7799,
May 2016, <http://www.rfc-editor.org/info/rfc7799>.
8.2. Informative References
[I-D.ietf-bier-oam-requirements]
Mirsky, G., Nordmark, E., Pignataro, C., Kumar, N.,
Aldrin, S., Zheng, L., Chen, M., Akiya, N., and S.
Pallagatti, "Operations, Administration and Maintenance
(OAM) Requirements for Bit Index Explicit Replication
(BIER) Layer", draft-ietf-bier-oam-requirements-01 (work
in progress), March 2016.
Authors' Addresses
Nagendra Kumar
Cisco Systems, Inc.
7200 Kit Creek Road
Research Triangle Park, NC 27709
US
Email: naikumar@cisco.com
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Carlos Pignataro
Cisco Systems, Inc.
7200 Kit Creek Road
Research Triangle Park, NC 27709-4987
US
Email: cpignata@cisco.com
Deepak Kumar
Cisco Systems, Inc.
3700 Cisco Way
SJ
US
Email: dekumar@cisco.com
Greg Mirsky
Ericsson
Email: gregory.mirsky@ericsson.com
Mach Chen
Huawei Technologies
Email: mach.chen@huawei.com
Eric Nordmark
Arista Networks
Email: nordmark@acm.org
Santosh Pallagatti
Juniper Networks
Email: santosh.pallagatti@gmail.com
David Mozes
Mellanox Technologies Ltd
Email: davidm@mellanox.com
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