Echo Request and Echo Reply for Overlay Networks
draft-ooamdt-rtgwg-demand-cc-cv-02

Abstract

This document defines Overlay Echo Request and Echo Reply that enable on-demand Continuity Check, Connectivity Verification among other operations in overlay networks.

Status of This Memo

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This Internet-Draft will expire on August 31, 2017.

Copyright Notice

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Table of Contents

• 1. Introduction
• 1.1. Conventions used in this document
• 1.1.1. Terminology
• 1.1.2. Requirements Language
• 2. On-demand Continuity Check and Connectivity Verification
• 2.1. Requirements Towards On-demand CC/CV OAM
• 2.2. Proposed Solution
• 2.3. Overlay Echo Request Transmission
• 2.4. Overlay Echo Request Reception
• 2.5. Overlay Echo Reply Transmission
• 2.6. Overlay Echo Reply Reception
• 3. IANA Considerations
• 3.1. Overlay Echo Request/Echo Reply Type
• 3.2. Overlay Ping Parameters
• 3.3. Overlay Echo Request/Echo Reply Message Types
• 3.4. Overlay Echo Reply Modes
• 4. Security Considerations
• 5. Contributors
• 6. Acknowledgment
• 7. References
• 7.1. Normative References
• 7.2. Informative References
• Authors' Addresses

1. Introduction

Operations, Administration, and Maintenance (OAM) toolset provides methods for fault management and performance monitoring in each layer of the network, in order to improve their ability to support services with guaranteed and strict Service Level Agreements (SLAs) while reducing operational costs.

1.1. Conventions used in this document

1.1.1. Terminology

Term "Overlay OAM" used in this document interchangeably with longer version "set of OAM protocols, methods and tools for Overlay networks". And "Overlay ping" is used intercheangeably with longer version Overlay Echo Request/Reply.

CC Continuity Check

CV Connectivity Verification

ECMP Equal Cost Multipath

FM Fault Management

Geneve Generic Network Virtualization Encapsulation

GUE Generic UDP Encapsulation

MPLS Multiprotocol Label Switching

NVO3 Network Virtualization Overlays

OAM Operations, Administration, and Maintenance

SFC Service Function Chaining

SFP Service Function Path

VXLAN Virtual eXtensible Local Area Network

VXLAN-GPE Generic Protocol Extension for VXLAN

1.1.2. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

2. On-demand Continuity Check and Connectivity Verification

2.1. Requirements Towards On-demand CC/CV OAM

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 (CC). Connectivity Verification (CV) extends Continuity Check functionality in order to provide confirmation that the desired source is connected to the desired sink.

Echo Request/Reply OAM mechanism enables detection of the loss of continuity defect, its localization and collection information in order to discover root cause. These are requirements considered:

• REQ#1: MUST support fault localization of Loss of Continuity check at Overlay layer.
• REQ#2: MAY support fault localization of Loss of Continuity check at transport layer.
• REQ#3: MUST support tracing path in overlay network through the overlay nodes.
• REQ#4: MAY support tracing path in underlay network connecting overlay border nodes.
• REQ#5: MAY support verification of the mapping between its data plane state and client layer services.
• REQ#6: MUST have the ability to discover and exercise equal cost multipath (ECMP) paths in its underlay network.
• REQ#7: MUST be able to trigger on-demand FM with responses being directed towards initiator of such proxy request.

2.2. Proposed Solution

    
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      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         Version Number        |         Global Flags          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Message Type  |   Reply mode  |  Return Code  | Return S.code |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Sender's Handle                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         Sequence Number                       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                              TLVs                             ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+