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Versions: (draft-tissa-trill-oam-req) 00 01 02 03 04 05 RFC 6905

TRILL Working Group                                  Tissa Senevirathne
Internet Draft                                                    CISCO
Intended status: Informational                               David Bond
                                                                    IBM
                                                             Sam Aldrin
                                                              Yizhou Li
                                                                 Huawei
                                                            Rohit Watve
                                                                  CISCO
                                                         Anoop Ghanwani
                                                                   DELL
                                                             Jon Hudson
                                                                Brocade
                                                           Naveen Nimmu
                                                               Broadcom
                                                          Radia Perlman
                                                                  Intel
                                                            Tal Mizrahi
                                                                Marvell

                                                           July 7, 2012
Expires: January 2013



   Requirements for Operations, Administration and Maintenance (OAM) in
                                   TRILL
                      draft-ietf-trill-oam-req-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
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   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




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   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html

   This Internet-Draft will expire on December 7, 2012.

Copyright Notice

   Copyright (c) 2012 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
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   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.



Abstract

   OAM (Operations, Administration and Maintenance) is a general term
   used to identify functions and toolsets to troubleshoot and monitor
   networks. This document presents, OAM Requirements applicable to
   TRILL. Also presented in this document is the proposed frame
   structure for TRILL OAM messages.

Table of Contents


   1. Introduction...................................................3
      1.1. Contributors..............................................3
   2. Conventions used in this document..............................4
   3. Terminology....................................................4
   4. OAM Requirements...............................................5
      4.1. Data Plane................................................5
      4.2. Connectivity Verification.................................5
         4.2.1. Unicast..............................................5
         4.2.2. Multicast............................................6
      4.3. Continuity Check..........................................6
      4.4. Path Tracing..............................................7
      4.5. General Requirements......................................7
      4.6. Performance Monitoring....................................8
         4.6.1. Packet Loss..........................................8


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         4.6.2. Packet Delay.........................................8
      4.7. ECMP Utilization..........................................9
      4.8. Security and Operational considerations...................9
      4.9. Fault Indications.........................................9
      4.10. Defect Indications......................................10
      4.11. Live Traffic monitoring.................................10
   5. General Format of TRILL OAM Messages..........................10
      5.1. Requirements of OAM Message channel......................12
   6. Security Considerations.......................................12
   7. IANA Considerations...........................................12
   8. References....................................................12
      8.1. Normative References.....................................12
      8.2. Informative References...................................13
   9. Acknowledgments...............................................13

1. Introduction

   OAM (Operations, Administration and Maintenance) generally covers
   various production aspects of a network. In this document we use the
   term OAM as defined in [RFC6291].

   Success of any mission critical network depends on the ability to
   proactively monitor networks for faults, performance, etc. as well
   as its ability to efficiently and quickly troubleshoot defects and
   failures.  A well-defined OAM toolset is a vital requirement for
   wider adoption of TRILL as the next generation data forwarding
   technology in larger networks such as data centers.

   In this document we define the Requirements for TRILL OAM. Also the
   proposed format for OAM frames is presented.

   It is assumed that the readers are familiar with the OAM concepts
   and terminologies defined in other OAM standards such as [8021ag],
   [RFC5860]. This document does not attempt to redefine the terms and
   concepts specified elsewhere.



1.1. Contributors

   The following members were part of the design team that produced
   this document. Their names are listed below in alphabetical order.

   Anoop Ghanwani, David Bond, Donald Eastlake, Jon Hudson, Naveen
   Nimmu, Radia Perlman, Rohit Watve, Sam Aldrin, Shivakumar Sundaram,
   Tal Mizrahi, Thomas Narten, Tissa Senevirathne, Yizhou Li.



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2. Conventions used in this document

   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 RFC-2119 [RFC2119].
   Although this document is not a protocol specification, the use of
   this language clarifies the instructions to protocol designers
   producing solutions that satisfy the requirements set out in this
   document.

3. Terminology

   Section: The term Section refers to a partial segment of a path
   between any two given RBridges. As an example, consider the case
   where RB1 is connected to RBx via RB2,RB3 and RB4. The segment
   between RB2 to RB4 is referred to as a Section of the path RB1 to
   RBx.

   Flow: The term Flow indicates a set of packets that share the same
   path and per-hop behavior (such as priority). A flow is typically
   identified by a portion of the inner payload that affects the hop-by
   hop forwarding decisions. This may contain Layer 2 through Layer 4
   information.

   All Least Cost Paths: The term "all least cost paths" refers to all
   potentially available least cost paths from a given source to a
   specified destination RBridge as determined by the TRILL network
   topology learned from IS-IS. ECMP: Equal Cost Multi Path.

   Connectivity: The term connectivity indicates reachability between
   an arbitrary RBridge RB1 and any other RBridge RB2. The specific
   path can be either explicit (e.g. specific flow) or unspecified.
   Unspecified means taking whatever the path connectivity verification
   message happen to take.

   Continuity Verification: Continuity Verification refers to proactive
   verification of Connectivity between two RBridges at periodic
   intervals and generation of explicit notification when Connectivity
   failures occur.

   Fault: The term Fault refers to an inability to perform a required
   action, e.g., an unsuccessful attempt to deliver a packet.

   Defect: The term Defect refers to an interruption in the normal
   operation, such that over a period of time no packets are delivered
   successfully.



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   Failure: The term Failure refers to the termination of the required
   function over a longer period of time. Persistence of a defect for a
   period of time is interpreted as a failure.

4. OAM Requirements

4.1. Data Plane

   OAM frames, utilized for connectivity verification, continuity
   checks, performance measurements, etc., MUST follow the same path as
   the specified flow.

   OAM frames, utilized for connectivity verification, continuity
   checks, performance measurements, etc., when a specific flow is not
   specified MUST follow whatever the path TRILL choose based on
   current topology, per-hop forwarding behavior and default flow
   entropy.

   RBridges MUST have the ability to identify OAM frames destined for
   them or which require processing by the OAM plane from normal data
   frames.

   RBridges MUST have the ability to differentiate between OAM frames
   and data frames experiencing errors.



   TRILL OAM frames MUST be confined to the TRILL domain and MUST NOT
   be forwarded out of the TRILL domain. E.g. they must not be sent as
   native frames on an end station service enabled port

   OAM MUST have the capability to provide services for both IP and
   non-IP flows.

   OAM MUST be able to function in IP and non-IP infrastructure.

4.2. Connectivity Verification

4.2.1. Unicast

   OAM MUST have the ability to verify connectivity from an arbitrary
   RBridge RB1 to any other RBridge RB2.

   OAM MUST have the ability to verify connectivity from an arbitrary
   RBridge RB1 to any other RBridge RB2 for a specific flow.




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   An RBridge SHOULD have the ability to verify the above connectivity
   tests on sections. As an example, assume RB1 is connected to RB5 via
   RB2, RB3 and RB4. An operator SHOULD be able to verify the RB1 to
   RB5 connectivity on the section from RB3 to RB5. The difference is
   that the ingress and egress TRILL nicknames in this case are RB1 and
   RB5 as opposed to RB3 and RB5, even though the message itself may
   originate at RB3.

   OAM MUST have the ability to invoke the above functions on-demand.

4.2.2. Multicast

   OAM MUST have the ability to verify connectivity, from an arbitrary
   RBridge RB1, to either to a specific set of RBridges or all member
   RBridges, for a specified multicast tree. This functionality is
   referred to as verification of the un-pruned multicast tree.

   OAM MUST have the ability to verify connectivity, from an arbitrary
   RBridge RB1, to either to a specific set of RBridges or all member
   RBridges, for a specified multicast tree and for a specified flow.
   This functionality is referred to as verification of the pruned
   tree.

   OAM MUST have the ability to invoke the above functions on-demand.

4.3. Continuity Check

   [RFC5860] defines Continuity Check as the ability of end points to
   monitor liveliness of a path or a section of a path [RFC5860]. We
   use similar semantics in this document where end points are the
   ingress or egress RBridges.

   OAM MUST provide functions that allow any arbitrary RBridge RB1 to
   perform a Continuity Check to any other RBridge.

   OAM MUST provide functions that allow any arbitrary RBridge RB1 to
   perform a Continuity Check to any other RBridge for a specified
   flow.

   OAM SHOULD provide functions that allow any arbitrary RBridge to
   perform a Continuity Check to any other RBridge over all available
   least cost paths.

   OAM SHOULD provide the ability to perform a Continuity Check on
   sections of any path within the network.




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   OAM SHOULD provide the ability to perform a multicast Continuity
   Check for specified multi-destination tree(s) as well as specified
   multi-destination tree and flow combinations. The former is referred
   to as an un-pruned multi-destination tree Continuity Check and the
   latter is referred to as a pruned tree Continuity Check.

   OAM implementations SHOULD support at least a minimum frequency of 1
   second of Continuity check.

   OAM implementations SHOULD support multiple concurrent Continuity
   sessions from and/or to the same RBridge.



4.4. Path Tracing

   OAM MUST provide the ability to trace a path between any two
   RBridges per specified unicast flow.

   OAM SHOULD provide the ability to trace all least cost paths between
   any two RBridges.

   OAM SHOULD provide functionality to trace all branches of a
   specified multi-destination tree (un-pruned tree)

   OAM SHOULD provide functionality to trace all branches of a
   specified multi-destination tree for a specified flow (pruned tree).

4.5. General Requirements

   OAM MUST provide the ability to initiate and maintain multiple
   concurrent sessions for multiple OAM functions between any arbitrary
   RBridge RB1 to any other RBridge.

   OAM MUST NOT require extensions to or modifications of the TRILL
   header.

   OAM MUST provide a single OAM framework for all TRILL OAM functions

   OAM, as practical and as possible, SHOULD provide a single framework
   between TRILL and other similar standards.

   OAM MUST maintain related error and operational counters. SUCH
   counters MUST be accessible via network management applications
   (e.g. SNMP).

   Operations of OAM MUST NOT result in errors on end devices.


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   OAM MAY be required to provide the ability to specify a desired
   response mode for a specific OAM message. The desired response mode
   can be either in-band, out-of band or none.

   The OAM Framework MUST be extensible to future needs of TRILL and
   the needs of other standard organizations.

   OAM MAY provide methods to verify control plane and forwarding plane
   alignments.

   OAM SHOULD leverage existing OAM technologies, where practical.

4.6. Performance Monitoring

4.6.1. Packet Loss

   In this document, term loss of a packet is used as defined in
   [RFC2680] (see Section 2.4 of RFC2680).

   NOTE: Term simulated flow below indicates a flow that is generated
   by an RBRidge RB1 for OAM purposes. The fields of the simulated flow
   may or may not be identical to the actual data. However, simulated
   flow is required to follow the intended path.

   OAM SHOULD provide the ability to measure packet loss statistics for
   a simulated flow from any arbitrary RBridge RB1 to any other
   RBridge.

   OAM SHOULD provide the ability to measure packet loss statistics
   over a segment, for a simulated flow between any arbitrary RBridge
   RB1 to any other RBridge.

   OAM SHOULD provide the ability to measure simulated packet loss
   statistics between any two RBridges over all least cost paths.

   An RBridge SHOULD be able to perform the above packet loss
   measurement functions either proactively or on-demand.

4.6.2. Packet Delay

   There are two types of packet delays -- one-way delay and two-way
   delay (Round Trip Delay).

   One-way delay is defined in [RFC2679] as the time elapsed from the
   start of transmission of the first bit of a packet by an RBridge
   until the reception of the last bit of the packet by the destination
   RBridge.


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   Two-way delay is also referred to as Round Trip Delay is defined
   similar to [RFC2681]; i.e. the time elapsed from the start of
   transmission of the first bit of a packet by an RBridge until the
   reception of the last bit of the packet by the same RBridge.

   OAM SHOULD provide functions to measure two-way delay between two
   RBridges for a specified flow.

   OAM SHOULD provide functions to measure two-way delay between two
   RBridges for a specified flow over a specific section.

   OAM MAY provide functions to measure one-way delay between two
   RBridges for a specified flow.

   OAM MAY provide functions to measure one-way delay between two
   RBridges for a specified flow over a specific section.



4.7. ECMP Utilization

   OAM MAY provide functionality to monitor the effectiveness of per-
   hop ECMP hashing. For example, individual RBridges could maintain
   counters that show how packets are being distributed across equal
   cost next hops for a specified destination RBridge or RBridges as a
   result of ECMP hashing.

4.8. Security and Operational considerations

   Methods MUST be provided to protect against exploitation of OAM
   framework for security and denial of service attacks.

   Methods SHOULD be provided to prevent OAM messages causing
   congestion in the networks. Periodically generated messages with
   high frequencies may lead to congestion, hence methods such as
   shaping or rate limiting SHOULD be utilized.

4.9. Fault Indications

   The term Fault refers to an inability to perform a required action,
   e.g., an unsuccessful attempt to deliver a packet [OAMOVER]. The
   unsuccessful attempt may be due to Hop Count expiry, invalid
   nickname, etc.

   OAM MUST provide a Fault Indication framework to notify faults to
   the ingress RBRidge of the flow or other interested parties (such as
   syslog servers).


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   OAM MUST provide functions to selectively enable or disable
   different types of Fault Indications.

4.10. Defect Indications

   [OAMOVER] defines "The term Defect refers to an interruption in the
   normal operation, such as a consecutive period of time where no
   packets are delivered successfully."

   OAM SHOULD provide a framework for Defect Detection and Indication.

   OAM implementations that provide Defect Indication MUST provide
   methods to selectively enable or disable Defect Detection per defect
   type.

   OAM implementations that provide Defect Indication MUST provide
   methods to configure Defect Detection thresholds per different types
   of defects.

   OAM implementations that provide Defect Indication facilities MUST
   provide methods to log defect indications to a locally defined
   archive such as log buffer or SNMP traps.

   OAM implementations that provide Defect Indication facilities SHOULD
   provide a Remote Defect Indication framework that facilitates
   notifying the originator/owner of the flow experiencing the defect,
   which is the ingress RBridge.

   Remote Defect Indication MAY be either in-band or out-of-band.

4.11. Live Traffic monitoring

   OAM implementations MAY provide methods to utilize live traffic for
   troubleshooting and performance monitoring.

   Implementations MAY leverage Data Driven CFM [8021Q] or IPFIX
   [RFC5101] for the purpose of performance monitoring.

5. General Format of TRILL OAM Messages

   The TRILL forwarding paradigm allows an implementation to select a
   path from a set of equal cost paths to forward a packet. Selection
   of the path of choice is implementation dependent. However, it is a
   common practice to utilize Layer 2 through Layer 4 information in
   the inner payload for path selection.




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   As specified above, OAM Messages are required to follow the exact
   path as the data packets.

   The proposed frame format for TRILL OAM messages is as follows.

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                               |
   .    Outer Header               . (variable)
   |                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                               |
   +    TRILL Header               + 8 bytes
   |                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                               |
   .   Flow Entropy                . 128 bytes
   .                               .
   |                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                               |
   .   OAM Message Channel         . Variable
   .                               .
   |                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



                   Figure 1 Frame format of OAM Messages



   Outer Header: Media dependent header. For Ethernet this included
   Destination MAC, Source MAC, VLAN (optional) and EtherType fields.

   TRILL Header: Minimum of 8 bytes when the Extended Header is not
   included [RFC6325]

   Flow Entropy: This is a 128 byte Fixed size opaque field. The field
   MUST be padded with zeros when the flow entropy is less than 128
   bytes. Flow entropy emulates the forwarding behavior of the desired
   data packets.

   OAM Message Channel: This is a variable size section that carries
   OAM related information. Reusing existing OAM message definitions
   such as [RFC4379] and [8021ag] will be explored.




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5.1. Requirements of OAM Message channel

   The OAM Message channel header MUST contain a version number

   The OAM Message channel header MUST contain flags that facilitate
   hardware level processing. (e.g. indicate this is two-way delay
   measurement probe)

   The OAM Message channel MUST contain time stamping in fixed
   locations to facilitate hardware level performance monitoring. (e.g.
   delay measurements).

   The OAM Message channel MUST have the ability to be extensible to
   include future capabilities without requiring a change to the
   version of the message header. (e.g. include TLV structures)

   The OAM Message header MUST contain a unique marker that allows for
   identifying the presence of the OAM channel. This marker MUST
   provide equal or better uniqueness compared to the IP checksum
   define in [RFC791]

   The OAM Message SHOULD provide methods to include arbitrary data to
   test functions such as MTU testing.

6. Security Considerations

   Security Requirements are specified in section 4.8.

7. IANA Considerations

   <TBD>

8. References

8.1. Normative References

   [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.

   [OAMOVER] Mizrahi, T, et.al., "An Overview of Operations,
             Administration, and Maintenance (OAM) Mechanisms", draft-
             ietf-opsawg-oam-overview-06, Work in Progress, March 2012.

   [RFC5860] Vigoureux, M., et.al., "Requirements for Operations,
             Administration and Maintenance (OAM) in MPLS Transport
             Networks", RFC5860, May 2010.



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   [RFC4377] Nadeau, T., et.al., "Operations and Management (OAM)
             Requirements for Multi-Protocol Label Switched (MPLS)
             Networks", RFC 4377, February 2006.

8.2. Informative References

   [RFC6325] Perlman, R., et.al., "Routing Bridges (RBridges): Base
             Protocol Specification", RFC 6325, July 2011.

   [RFC5101] Claise, B., "Specification of the IP Flow Information
             Export (IPFIX) Protocol for the Exchange of IP Traffic
             Flow Information", RFC5101, January 2008.

   [RFC2680] Almes, G., et.al. "A One-way Packet Loss Metric for IPPM",
             RFC 2680, September 1999.

   [RFC2679] Almes, G., et.al. "A One-way Delay Metric for IPPM", RFC
             2679, September 1999.

   [RFC2681] Almes, G., et.al. "A Round-trip Delay Metric for IPPM",
             RFC 2681, September 1999.

   [RFC6291] Anderson, L., et.al. "Guidelines for the Use of the "OAM"
             Acronym in the IETF", RFC 6291, June 2011.

   [8021ag] IEEE, "Virtual Bridged Local Area Networks Amendment 5:
             Connectivity Fault Management", 802.1ag, 2007.

   [8021Q] IEEE, "Media Access Control (MAC) Bridges and Virtual
             Bridged Local Area Networks", IEEE Std 802.1Q-2011,
             August, 2011.

   [RFC791] "Internet Protocol", RFC 791, September 1981.

   [RFC4379] Kompela, K., et.al. "Detecting Multi-protocol Label
             Switched (MPLS) Data Plane Failures", RFC 4379, February
             2006.

   [RFC4377] Nadeau, T., et.al. "Operations and Management (OAM)
             Requirements for Multi-protocol Label Switched
             (MPLS)Networks", RFC 4377, February 2006.

9. Acknowledgments

   Special acknowledgments to IEEE 802.1 chair, Tony Jeffree for
   allowing us to solicit comments from IEEE 802.1 group. Also



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   recognized are the comments received from IEEE group, Ayal Loir and
   others.

   This document was prepared using 2-Word-v2.0.template.dot.

Authors' Addresses

   Tissa Senevirathne
   CISCO Systems
   375 East Tasman Drive
   San Jose, CA 95134
   USA.

   Phone: +1-408-853-2291
   Email: tsenevir@cisco.com


   David Bond
   IBM
   2051 Mission College Blvd
   Santa Clara, CA 95054
   USA

   Phone: +1-603-339-7575
   Email: mokon@mokon.net


   Sam Aldrin
   Huawei Technologies
   2330 Central Express Way
   Santa Clara, CA 95951
   USA

   Email: aldrin.ietf@gmail.com















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   Yizhou Li
   Huawei Technologies
   101 Software Avenue,
   Nanjing 210012
   China

   Phone: +86-25-56625375
   Email: liyizhou@huawei.com

   Rohit Watve
   CISCO Systems
   375 East Tasman Drive
   San Jose, CA 95134
   USA.

   Phone: +1-408-424-2091
   Email: rwatve@cisco.com


   Anoop Ghanwani
   DELL
   350 Holger Way
   San Jose, CA 95134
   USA.

   Phone: +1-408-571-3500
   Email: Anoop@duke.alumni.duke.edu

   John Hudson
   Brocade
   120 Holger Way
   San Jose, CA 95134
   USA.

   Email: jon.hudson@gmail.com


   Naveen Nimmu
   Broadcom
   9th Floor, Building no 9, Raheja Mind space
   Hi-Tec City, Madhapur,
   Hyderabad - 500 081, INDIA

   Phone: +1-408-218-8893
   Email: naveen@broadcom.com




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   Radia Perlman
   Intel Labs
   2700 156th Ave NE, Suite 300,
   Bellevue,  WA  98007
   USA.

   Phone: +1-425-881-4824
   Email: radia.perlman@intel.com


   Tal Mizrahi
   Marvell
   6 Hamada St.
   Yokneam, 20692 Israel

   Email: talmi@marvell.com

































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