PoV: Bringing Telco PaaS functionality to Project Sylva with XGVela integration [Draft]

1. Objective

As XGVela Telco PaaS has rich feature set to manage and monitor Network functions, this paper trying to evaluate the fitment of XGVela to Telco PaaS requirements of Project Sylva and identify integration gaps and aligning roadmaps.

1. About Project Sylva

The project Sylva is an industry grade cloud native platform to cover telco and edge use cases. Started as exploratory mode by 5 carriers Deutsche Telekom, Telefonica, Telecom Italia, Vodafone, Orange  and Two network vendors Ericsson and Nokia.  It defines a framework with all prerequisites - 5G, OpenRAN, EDGE cases and provides reference implementation  covering specific Hardware, network cards, GPU with multi tenancy, service mesh advanced security, sustainability features.

Key Objectives:

• • Simplify & Automate the operational model.
  • Interoperability - Validation program, large adoption
  • Reduce the fragmentation of the Telco Cloud
  • Reduce Cost (opensource, mutualization) and avoid lock-in

Sylva is amalgamation of multiple open source components from CNCF, LF Networking and Edge.  It consists of IaaS, CaaS and PaaS layers.  Even Though the primary focus is Kubernetes, it also has legacy support of Openstack, VMware etc.,

1. About  XGVela

XGVela  is 5G cloud-native open-source framework that introduces Platform-as-a-Service (PaaS) capabilities for telecom operators. Main target of it is for delivering common and reusable PaaS capabilities required in the processes of network function development/running, network cloud management/maintenance, network cloud capability exposure and etc., so that applications are lightweight and contain only code to deliver the intended business logic.  Also its management-related Telco PaaS functions implements services, configuration management, fault management, log management, performance management, topology management and high availability for the managed NFs. 

XGVela High-Level Architecture:

XGVela PaaS capabilities:

General PaaS section of XGVela can provide the abstract tools, services and environment required in the process of development, deployment, running, operation and management of applications and their associated services. General PaaS capabilities are standard cloud capability which can be offered by any cloud provider, and it will have the capabilities to be shared by a number of industry specific PaaS including Telco PaaS. In short, General PaaS refers to commonly used PaaS capabilities by all industries (e.g. service mesh, API GW, LB, observability) and existing open-source PaaS implementations (e.g. Istio, envoy, Zookeeper, Grafana). XGVela takes those implementations for integration instead of re-inventing the wheels.

The Adaptation Layer is unique enhancement of General PaaS capability when applied to telecom scenario. To avoid coupling with General PaaS, the enhancement would be implemented in the form of plug-ins, drivers, and other non-invasive forms. In telecom scenario, the General PaaS capability is usually used in combination with corresponding adaptation layer enhancement points. For example, many load balancer software supports HTTP, TCP, UDP, while for 5G network functions, e.g. UPF, protocols like PFCP, GTPU are used in control plane and data plane flow. If a developer wants to use existing open-source load balancer in 5G core, PFCP and GTPU protocol analysis capability should be enhanced for that LB and delivered together with the LB to provide service.

The Telco PaaS focuses on delivering telecom specific PaaS capabilities, which implements telecom features such as multi-tenancy, multiple network plane, network function topology, network function configuration, etc. These capabilities are used to serve telecom network functions and telecom management systems. Some Telco PaaS needs to interwork with General PaaS to deliver complete PaaS service.

These above PaaS capabilities together constitute XGVela, which provides all "platform" services for cloud native Telecom workloads. Developers can make combinations freely of general PAAS, general PAAS + adaptation and telco PAAS based on requirements.

1. How XGVela Complements Sylva for Telco PaaS

The advantages that XGVela based for telco application and telco cloud features:

1. 1. The heartbeat/healthcheck need to be much faster for telco app compared to regular non-telco microservices.
   2. Kubernetes supports the liveness/readiness which are in the orders of 10s of seconds. However, telco app needs sub second heartbeat check.
   3. Dynamic injections of configuration to the telco network functions required without restarting network functions.
   4. Typical network functions contains multiple smaller microservices to realize overall telco functionality. Health checks and monitoring should be across the components of the network function instead of individual PODs.
   5. Topology of a network function consisting of multiple microservices, how the traffic flowing across services is critical for the monitoring.

   6. Opportunities to generalize certain Telco specific functions such as subscriber tracing, Lawful Intercept (LI), CDR (Call Data Records), etc.

   7. The fault management service implements 3GPP compliant fault and alarm management model and provides interfaces for application µService to publish and subscribe to various events.

   8. Kubernetes does not meet fast HA requirements needed for certain Telco stateful services, whereas it provides overlay HA capability by supporting Active-Standby model in a distributed scalable fashion.

1. Next Steps

1. Reference Documents