SRv6 for Power Grid
draft-lu-srv6ops-srv6-for-power-grid-00

Network Working Group                                              J. Lu
Internet-Draft                 China Southern Power Grid Company Limited
Intended status: Experimental                                    X. Geng
Expires: 24 April 2025                                            Huawei
                                                         21 October 2024

                          SRv6 for Power Grid
                draft-lu-srv6ops-srv6-for-power-grid-00

Abstract

   This document outlines the deployment of Segment Routing over IPv6
   (SRv6) in the power grid communication network, including power grid
   services, requirement analysis, network structure and different srv6
   deployment scenarios.

Requirements Language

   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].

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirement Analysis of Network for Power Grid  . . . . . . .   3
     2.1.  Requirements for Network Capabilities in Power Grid
           Services  . . . . . . . . . . . . . . . . . . . . . . . .   3
       2.1.1.  Production Services . . . . . . . . . . . . . . . . .   3
       2.1.2.  Management Office Services  . . . . . . . . . . . . .   4
       2.1.3.  Electricity Trading . . . . . . . . . . . . . . . . .   4
     2.2.  Gap Analysis for Power Grid Data Network  . . . . . . . .   5
       2.2.1.  Challenges in Multi-Service Integration and
               Assurance . . . . . . . . . . . . . . . . . . . . . .   5
       2.2.2.  Limited Network Scalability . . . . . . . . . . . . .   5
   3.  Network Structure in Power Grid . . . . . . . . . . . . . . .   5
   4.  SRv6 Deployment Scenario in Power Grid  . . . . . . . . . . .   6
     4.1.  SRv6 Migration  . . . . . . . . . . . . . . . . . . . . .   6
     4.2.  SRv6 Inter-domain . . . . . . . . . . . . . . . . . . . .   7
     4.3.  SRv6 based Path Selection and Load balancing  . . . . . .   7
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   8.  Normative References  . . . . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   Segment Routing over IPv6 (SRv6) has seen increasing deployment in
   service provider networks, driven by its ability to simplify network
   operations and improve scalability.  SRv6 extends the capabilities of
   traditional IP routing by enabling flexible path steering, traffic
   engineering, and network programmability, as specified in existing
   RFCs such as RFC 8754 and RFC 8986.  These features make SRv6
   particularly suitable for complex network environments like the power
   grid, where diverse and critical services need to be supported
   efficiently.

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   The power grid communication network supports multiple services with
   varying requirements, including real-time monitoring, substation
   communication, and control system coordination.  The hierarchical
   network structure, comprising backbone and municipal levels, provides
   a robust foundation for deploying SRv6 to meet these demands.  SRv6's
   ability aligns well with the needs of power grid services, enabling
   efficient management of service-level agreements (SLAs) and enhancing
   network reliability.

   This document presents the experience of deploying SRv6 in a power
   grid communication network, covering aspects such as service
   requirements, network structure, and various deployment scenarios.

2.  Requirement Analysis of Network for Power Grid

2.1.  Requirements for Network Capabilities in Power Grid Services

   The power grid network supports two primary service categories:
   production dispatch & management and marketing information.  These
   are further divided into voice, data, and video communications, each
   with specific network requirements to ensure reliable power grid
   operations

2.1.1.  Production Services

   • Voice Communication:

      Dispatch Calls: Critical voice communications between dispatch
      centers, power plants, and substations must maintain high
      availability with the highest priority.

   • Video Communication:

      Substation Surveillance: Video data from unmanned substations is
      crucial for monitoring specific areas in real time.  This data
      requires transmission rates between 384 kbit/s and 8 Mbit/s
      (commonly 2 Mbit/s), with a transmission delay of ≤250 ms, an
      error rate not exceeding 10^-5, and availability requirements of
      99.9%.

   • Data Communication:

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      Relay Protection and Safety Automation: Signals for relay
      protection between high-voltage transmission lines and grid safety
      devices must be highly reliable and have low, fixed transmission
      delays, including fast command information and real-time data for
      safety devices.  High reliability and low transmission delay are
      essential for safety signals, with requirements such as delays
      below 50.

      Dispatch Automation Data: Real-time monitoring and control data
      for grid operation are required.  Remote data includes telemetry,
      signaling, control, and regulation information, with transmission
      rates ranging from 64 kbit/s to 384 kbit/s, a delay of ≤250 ms,
      and an error rate of 10^-5.

2.1.2.  Management Office Services

   • Management Information Services:

      Management information services include financial management,
      marketing, production planning, human resources management, safety
      supervision information, and information support systems.

   • Management Office Services:

      Management office services cover office communication and
      information management to meet internal and external enterprise
      communication needs.

2.1.3.  Electricity Trading

   • Energy Metering Data:

      Transmission methods can include dispatch data networks or
      dedicated circuits, with a transmission error rate not exceeding
      10^-6 and availability requirements of 99.99%.

   • Trading Data:

      Spot and futures market data involve substantial data volumes,
      demanding high transmission accuracy for forecasting and
      transactions.

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2.2.  Gap Analysis for Power Grid Data Network

   Traditional MPLS-based power grid data network could provide secure
   network isolation and multi-service integration.  However, with the
   growing scale of the grid network and the surge in digital services,
   MPLS technology faces challenges in meeting requirements of power
   grid.  The main gaps are as follows:

2.2.1.  Challenges in Multi-Service Integration and Assurance

   • Limitations of QoS and Traffic Engineering: Although MPLS
   theoretically supports Quality of Service (QoS) and traffic
   engineering for bandwidth guarantees, these techniques have
   limitations.  For example MPLS RSVP TE (Traffic Engineering) requires
   pre-reserving bandwidth at each network node, resulting in a complex
   deployment process New digital services demand more advanced network
   assurance technologies to support comprehensive multi-service
   integration.

2.2.2.  Limited Network Scalability

   • Increased Demand for Address Space and IPv6 Transition: The new
   power system, driven by renewable energy, requires interaction
   between diverse sources, network load, and storage, leading to a need
   for extensive network connectivity.  The deployment of intelligent
   terminals will necessitate a shift to an IPv6 single-stack network,
   which the current MPLS network does not support.

   • Limited Traffic Scheduling Flexibility: With the rise of smart
   substations and video surveillance, network bandwidth demands are
   increasing.  MPLS struggles to balance traffic across multiple paths,
   resulting in uneven bandwidth utilization and congestion.

3.  Network Structure in Power Grid

   The power grid communication network is structured into two levels:
   backbone and municipal.  Each level consists of three layers—core,
   aggregation, and access—creating a clear network topology that
   facilitates traffic path determination and adjustment.

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   The core layer of the backbone level adopts a fully meshed network
   architecture.  The aggregation layer routers are connected in a dual-
   uplink tree topology, linking to the access layer devices, which
   helps distribute traffic and reduce the load on the core routers.
   Access layer devices are connected to different aggregation equipment
   based on service requirements or geographical locations.  Key
   departments such as the headquarters dispatch center, headquarters
   office area, and data centers are directly connected to the national
   backbone network.

   Each municipal network operates as a separate Autonomous System (AS)
   and also comprises the core, aggregation, and access layers, with
   dual uplinks to the upper-level network.  Most access devices in the
   municipal networks use either ring topology or dual-uplink tree
   topology, connecting to substations, power supply bureaus, dispatch
   centers, and other local facilities.

   The power grid communication network supports two types of service
   scenarios based on the scope of business access: intra-domain closed-
   loop services and inter-domain cross-access services.

   In the intra-domain scenario, the access network facilitates business
   activities within a single domain, such as connecting from a power
   supply station to the municipal data center.  This setup is centrally
   managed within the domain and uses EVPN L3VPN over SRv6 Policy for
   service delivery.  All network elements within the domain are
   controlled by a unified controller, enabling rapid service
   provisioning, efficient intra-domain traffic path planning, and
   traffic optimization.

   For the inter-domain scenario, where cross-domain business access is
   required, the network accommodates the transition from traditional
   MPLS VPN networks by adopting the Option A inter-domain approach.
   This method helps address synchronization issues during network
   upgrades and ensures a smooth transition across domains.  The entire
   network is planned under a unified framework set by the power grid
   corporation, with clearly defined VPN categories across the network.
   Through segmented deployment of EVPN L3VPN over SRv6 Policy, each
   segment can be optimized for business traffic.

4.  SRv6 Deployment Scenario in Power Grid

4.1.  SRv6 Migration

   TBD

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4.2.  SRv6 Inter-domain

   TBD

4.3.  SRv6 based Path Selection and Load balancing

   TBD

5.  IANA Considerations

   This document makes no request of IANA.

   Note to RFC Editor: this section may be removed on publication as an
   RFC.

6.  Security Considerations

7.  Acknowledgements

8.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

Authors' Addresses

   Jiangang Lu
   China Southern Power Grid Company Limited
   Email: lujiangang@gddd.csg.cn

   Xuesong Geng
   Huawei
   Email: gengxuesong@huawei.com

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