5G-PPP Software Network White Paper 畫重點筆記

From Webscale to Telco, the Cloud Native Journey

https://5g-ppp.eu/white-papers/

這邊是一篇”畫重點”的筆記,關於 5G & Cloud Native ,From 5G-PPP(5G Infrastructure Public Private Partnership) 的白皮書。

1 Introduction

  • Software in 5G-PPP so far
    • from “boxes” to “functions”, and from “protocols” to “APIs”
  • Cloud impact in general
  • Cloud impact in telecom ecosystem in particular

    • covering Service-Oriented Architecture (SOA), Microservices Architecture (MSA) and Service-Based Architecture (SBA), the latter being adopted in next generation CORE [15]
    • telcograde enhancements that should be added in frameworks like Kubernetes, monitoring, stateless design, etc…
    • What are the specific requirements between Webscale and telco players?
    • What gaps do we have in container management eco-system to achieve telco-grade performance?
    • Which segments are critical from latency perspective?
    • What features are required to support micro-services architecture in all the segments?
    • Which factors are difficult to implement in telco (from https://12factor.net)?
  • 章節介紹如下:

    • 2 介紹了基於服務的體系結構,12個因素以及網絡,虛擬化,編排等所需的技術。
    • 3 列出了電信公司的要求。
    • 4 描述了電信級的增強功能。
    • 5 簡要概述了技術推動因素,開源和標準。
    • 6 結論。

2 Cloud Native: a Webscale View

SBA(Service-Based Architecture)

3 ways to implement:
either as a network element on a dedicated hardware
as a software instance running on a dedicated hardware
as a virtualized / cloud-native function instantiated on an appropriate platform

利用雲軟件技術,3GPP NF架構可實現更高的靈活性,可編程性,自動化以及顯著的成本/能耗降低。

2.1 Microservice Architecture

提供超可靠,低延遲的通信和高速
為此,需要在架構中實現高度靈活性,可歸納如下:

  • 支持對網絡的不同要求,如網絡容量,數據速率,傳輸延遲,信息安全;
  • 支持向運營商的服務和第三方應用程序公開網絡功能
  • 支持輕鬆部署和維護。 每個功能都應該能夠根據新的要求進行升級,並根據系統能力進行橫向擴展,而不會影響其他功能。

SBA benefits to 5G:

  • Easy update of Network:
    • Finer granularity allows individual services to be upgraded with minimal impact to other services.
    • Facilitated continuous integration reduces the time-to-market for installing bug fixes and rolling out new network features and operator applications.
  • Extensibility:
    • Light-weighted service-based interfaces are needed to communicate across services.
  • Modularity & Reusability:
    • The network is composed of modularized services reflecting the network capabilities and provides support to key 5G features such as network slicing.
    • A service can be easily invoked by other services (with appropriate authorization), enabling each service to be reused as much as possible.
  • Openness

    • Together with some management and control functions (i.e. authentication, authorization, accounting), the information about a 5G network can be easily exposed to external users such as 3rd parties through a specific service without complicated protocol conversion

      2.2 Twelve Factors

https://12factor.net/zh_cn/

2.3 Technology for Cloud Native

Cloud Native Trail Map
https://github.com/cncf/landscape/blob/master/README.md#trail-map

3 Telco Requirements

  • 5G Service Enablers
    • eMBB – Enhanced Mobile Broadband
    • mMTC – Massive Machine Type Communications
    • URLLC –Ultra-Reliable and Low Latency Communications

IMT-2020 5G Triangle

  • 3.1 Service Requirement: 99.999%
  • 3.2 Application Type: like multi-access edge computing (MEC)
  • 3.3 Deployment Environment
  • 3.4 Operability: Need monitoring system
  • 3.5 Business Environment
  • 3.6 Human Factors

4 Toward Telco Grade Webscale Frameworks

4.1 Need for Telco Grade features

  • Open and modular software
  • Intelligence in software
  • Scalable and efficient

  • Typically, telco key performance indicators taken into account include latency and bandwidth, availability and security.

    • For instance, since each microservice contributes in the overall latency, it is challenging to predict the latency of a specific service, especially in cases of large and distributed systems.
    • container management technologies (Kubernetes, Mesos, Swarm) are using an overlay network (Layer 4) which is not optimized for low latency requirements, e.g. in the cloud RAN
    • network availability, as 99.999% availability is commonly set by the operators. Currently, cloud-native applications are not built to handle bandwidth, latency and network availability requirements.
    • container management include the lack of a dynamic carrier-grade orchestration, the management of containers across different sites and data centers and the lack of centralized controllers for networking aspects with respect to provisioning, resiliency, management/coordination, automatic network configuration and visibility of traffic from container-to-container across networks -whether physical or virtual.
  • 為了滿足上述要求,必須滿足以下條件:

    • Automation of operations, upgrade, backup and restore as well as restart capabilities
    • Monitoring, performance counter, alarms and logging/trace support
    • Security and tenant isolation.

4.2 Twelve Factors in Telco Domain

  • Build/Release/Run (12.V) is not a part of ETSI standards
  • dependency declaration and management (12.II) should be of particular concern
  • the codebase (12.I) and Dev/Prod parity (12.X) which should accommodate various deployments strategies over a potentially multi-cluster multi-vendor environment.
  • factors 12.VIII (Concurrency) and 12.VI (Processes) 12.IX (Disposability) and 12.XI (Logs) pose the greatest challenges ahead for the participating 5G projects.
  • Logs (12.XI) speed, heterogeneity and variability of origin will force a readjustment of current telco methodologies.
  • Disposability (12.IX), i.e. small start-up times and graceful termination, is major concern for five nines availability systems, especially for emergency services and in relation to QoS constraints.
  • the factor on administrative processes (12.XII) seems a key aspect, and especially critical since it has less to do with technology evolution.

4.3 Telco-Grade Features

Several features must be integrated to the aforementioned frameworks:

  1. Multi-network interfaces
  2. Service function chaining
  3. Data plane acceleration
    • low packet processing time to reach very low latency
    • predictability and stability of packet processing delay to minimize jitter
    • guaranteed and prioritized bandwidth for each Telco workload to prevent network contention
    • low CPU consumption for network tasks to allow low energy usage
    • native network performance for Telco workloads
  4. Enhanced platform awareness
    • CPU pinning to avoid unpredictable latency and host CPU overcommit by dedicating CPUs to the Telco containers
    • Numa awareness to improve the utilization of compute resources for Telco containers that need to avoid cross NUMA node memory access
    • huge pages to accelerate the memory management by using larger page sizes.
  5. Environment aware scheduling

5 Technology Enablers – Open source and Standards

5.1 Standards

5.2 Open Source Software

可以參考 CNCF 的軟體來實作
MANO frameworks such as Linux Foundation’s ONAP [41], ONF XOS [42], Cloudify [43] and ETSI OSM [44] are starting to evolve towards this approach for microservices.

6 Conclusion

  • The VNFs are now broken into pieces, support continuous integration and continuous development (CI/CD) and interact using service meshes.
  • Compare the three architectures inspired from the domain driven design
    • Service Oriented Architecture
    • Service Based Architecture
    • Microservice Architecture
  • the new VNFs, microservice, are designed, a set of technology used to deploy, orchestrate, network and monitor them.
  • Telco grade features
  • The telco requirements that are needed to be supported in community developed open source.
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