This section provides an overview of the deployment topologies and considerations for 5G Core, RAN, OSS, and legacy NF use cases and architectures commonly used by Communication Service Providers (CSPs).
Telco Cloud Building Blocks
The figure below highlights the functional building blocks for the Telco Cloud, each of these building blocks needs a component set that specifically fulfills the needs of the Telco Cloud Platform from an end-to-end perspective.
Telco Cloud Infrastructure:
Hypervisor / VI: The hypervisor is an important component of the Telco Cloud. The Hypervisor allows for the ability to run (execute) multiple workloads on a single server, This serves to offer improved asset utilisation, a lower total cost of ownership and the ability to run divergent workloads simultaneously.
The hypervisor of choice for the Telco Cloud Platform is VMware ESXI coupled with the VI (Virtual Infrastructure) component vCenter creates the product set collectively known as vSphere. This layer provides the best-in-breed Hypervisor and Hypervisor Management capabiliies while continually evolving to support new and demanding Telco requirements.
In order to be efficient, the hypervisor should support the following advanced options to ensure optimal performance of all telco related workloads:
Enhanced Platform Awareness: (NUMA Alignment, CPU Pinning, Symmetrical Hyperthreading, SR-IOV support and so on).
IPv6 capabilities: To support modern IP addressing requirements from Telco Customers
Physical and Virtual device Pass-Through (PT): To provide capabilities to expose server hardware to the guest OS, for example inline ./ look-aside accelerators for RAN use cases
Energy Efficiency configurations: To be able to balance the requirements for high-performance with energy efficiency
Live Patching: To simplify security updates while minimizing operational impact
Software Defined Storage: The ability of Software Defined Storage (SDS) is to provide a highly scalable, performant and robust storage platform to the Telco Cloud, A shared storage environment that leverages software policies to be able to offer simultaneously multiple storage offerings based on the workload needs while also supporting the ability to dynamically change the storage requirements.
The architecture of choice for the Telco Cloud Platform is to leverage a HyperConverged infrastructure (HCI), in this model the Disks (SSDs / NVMe) that are physically installed in the server are used to provide a portion of the overall data-storage platform.
VMware vSAN is the preferred Software Defined Storage platform, although Telco Cloud operators are free to choose from the many interopable storage solutions that are compatible with the Hypervisor / VI layer. This include NVMe over Fabric, iSCSI, NFS, FCoE platforms.
vSAN is preferred as it provides the following options to maximise performance and storage operations across the Telco Cloud:
Highly Available Storage platform, with the ability to grow on demand without impacting pre-existing workloads
Highly performant: Able to deliver against the most I/O intensive workloads
Software Policy Support: To be able to leverage software policies to simplify and manage storage requiremens for multiple different workloads.
Cost eficient: does not require expensive external storage arrays which can complicate architectures.
Software Defined Networking: The ability of Software Defined Networking (SDN) is to provide a software based implementation of traditional switching, routing, security and other networking related features independent of the physical networking infrastructure. The SDN creates a separation of the control-plane and data-plane components of networking, leveraging manager or controller to run control plane components while forwarding is distributed throughout the infrastructure.
The platform of choice for the Telco Cloud Platform is VMware NSX. The NSX platform integrates with the vSphere Hypervisor to provide all of the requirement software networking constructs with maximum efficiency allowing for operators to be more agile in creating the required networking topologies reuqired for complex telco network functions.
In addition, several features from NSX have been enhanced based on the complex and wide-ranging requirements from telco customers including:
Enhanced Data Path (EDP) Forwarding: A hypervisor kernel based DPDK implementation to provide dramatically increased throughput for data-plane applications while still supporting traditional cloud architectural requirements
VRF & BGP eVPN: Advanced BGP Ethernet VPN topologies, couple with Virtualised Routing and Forwarding instances to allow for more control plane / data-plane scalability while supporting more modern and advanced network architectures.
IPv6 support: To comply with telco customer requirements for IPv6 across all components within the telco cloud.
Virtual Infrastructure Manager: The Virtual Infrastructure Manager (VIM) is a key component in the ETSI / NFV framework. The VIM is responsible for managing and controlling the underlying infrastructure, in the Telco Cloud Platform this mean the Hypervisor, Software Defined Storage and Software Defined Networking layers.
The VIM retains overall responsibility for the southbound interaction with the Telco Cloud Infrastructure tier as well as providing northbound interfaces for external orchestration platforms to integrate with
The platform of choice for the VIM layer is VMware Cloud Director. The VMware Cloud Director platform is a proven, robust VIM platform that has continually evolved to meet the stringest of reuirements for telco customers.
Cloud Director also has strong ties into the VI, Software Defined Networking and Software Defined Storage layers and complements the overall Telco Cloud Platform architecture, the VIM also supports a number of enhancements that are necessary for telco customers including:
Multi-Tenancy: A key component of the VIM layer is to provide multi-tenancy for different tenants, allowing for a controlled environment where different tenants can onboard workloads with vastly different requirements.
Resource Allocation: Cloud Director supports advanced resource allocation models that allow for the support of control-plane and data-plane network functions to co-exist on the same hardware and run side-by-side.
IPv6 support: To comply with telco customer requirements for IPv6 across all components within the telco cloud.
L4 - L7 Load Balancer: The Load-Balancer is a key component throughout the Telco Cloud Platform, this provides a secure and highly available platform for load-balancing services for some of the management components within the Telco Cloud Platform.
The functionality of this should also extend to supporting Load-Balancing for the VIM platform as well as Load-Balancing and Ingress services for cloud-native workloads, ideally a single platform should be used for operational simplicity and costing.
The platform of choice for the L4-L7 Load Balancer layer is VMware Advanced Load-Balancer (aka Avi). The VMware Advanced Load-Balancer offers full support for all workload types with a single managment plane and a scalable, distributed data-plane/
The VMware Advanced Load Balancer has evolved to support many use-cases and acts as a single platform for all L4 - L7 use-cases, specific enhancement for Telco workloads include:
SCTP Support: Support for Stream Control Transmission Protocol, a common replacement for TCP within telco applications
IPv6 support: To comply with telco customer requirements for IPv6 across all components within the telco cloud.
It should be noted that NSX does offer L4 Load-Balancing services, however this is constrained for usage in the Managment domain and only for those appliances provided as part of the Telco Cloud that require the uses of an external load-balancer. Thus while this may be viable for simple L4 Load-Balancing use-cases such as providing L4 Load-Balancing to the VIM layer (Cloud Director) it cannot be leveraged across workload domains or in the Kubernetes domain as a service LoadBalancer or Ingress.
Telco Cloud CaaS:
Kubernetes: Kubernetes has become the defacto standard orchestration platform for containerised / microservices based workloads, offering declarative models for workload deployments, self-healing capabilities as well as dynamic scaling and distributed deployment models.
Currently in the Telco Cloud Platform, for both Core and RAN use-cases the use of Kubernetes requires the use of a hypervisor layer. The Management/Control plane as well as the worker nodes of Kubernetes run as Virtual Machines atop of the hypervisor based infrastructure.
This model allows for different telco workloads to run on the same physical hosts, even workloads that have different Kubernetes version, different kernel versions (Real-Time vs. Non-Real Time Kernel releases) as well as diverse networking requirements - all serviced by the IaaS layer.
The Kubernetes distribution of choice for the Telco Cloud Platform is VMware Tanzu Kubernetes Grid. The VMware Tanzu Kubernetes Grid platform offers a wide range of kubernetes releases and functionality packed in a convenient model that reduces the complexity of building and supporting various kubernetes distributions.
The VMware Tanzu Kubernetes Grid component within the Telco Cloud Platform is also supplemented by additional features specific to the Telco Cloud Platform, including:
Complex networking architectures: Supporting Multus, SR-IOV and DPDK requirements for data-plane workloads
IPv6 capabilities: To support modern IP addressing requirements from Telco Customers
Physical and Virtual device Pass-Through (PT): To provide capabilities to expose server hardware to the kubernetes layer, for example exposing NIC PTP or GNSS timing capabilities to the Network Function
Telco Operators: The Telco Cloud Platform deploys additional operators into the VMware Tanzu Kubernetes environment to support massive automated customisation of the kubernetes environment, everything from changing kernel version and paramaters to exposing Platform Awareness features and supporting declarative requirements that govern how both the Virtual Machine, Guest Operating System and Kubernetes are configured
Telco Cloud Automation: Telco Cloud Automation (TCA) is a foundational component within the Telco Cloud Platform. TCA is responsible for the creation and lifecycle of both Kubernetes clusters as well as for the design, instantation lifecycle managment of both VNF and CNF based workloads.
The hypervisor of choice for the Telco Cloud Platform is VMware ESXI coupled with the VI (Virtual Infrastructure) component vCenter creates the product set collectively known as vSphere. This layer provides the best-in-breed Hypervisor and Hypervisor Management capabiliies while continually evolving to support new and demanding Telco requirements.
To simplify the operational capabilities of the Cloud Native Telco, TCA supports the following common requirements for Telco workloads
Multi Kubernetes Relases: Support for managing and providing efficent lifecycle management of Tanzu Kubernetes Grid clusters accross multiple releases to allow for operator defined cadence for cluster / NF lifecycle.
IPv6 capabilities: To support modern IP addressing requirements from Telco Customers
Infrastructure Policies: Supporting advanced configuration of Telco Workloads in a declarative fashion to allow Telco Operators to customise Kubernetes Cluster to be fit for the intended workload, this takes the complexity away from managing a fleet of diverse kubernetes clusters.
Tenancy: Support for tenancy and RBAC to allow for TCA to act as a secure tenant interface to the Telco Cloud Native environment, providing secure access to kubernetes clusters as well as the management platform.
Certificate Management: TCA provides the Telco operator with a simple interface to view and in the future manage all of the integrated components and their public facing certificates.
Workflow hub: Providing a serverless based workflow engine that allows for easy integration into CI/CD/CT toolchains and to complete the automation journey for Telco customers.
Telco Cloud Container Registry: The Telco Cloud Container registry is a major component within any cloud-native deployment. The Container Registry hosts the Open Container Initiative (OCI) Images and HELM charts. These are the cloud-native nework functions and the model of how they should be deployed in a kubernetes environments.
The Container Registry of choice for the Telco Cloud Platform is Harbor, this is provided as part of the Telco Cloud Platform as a cloud-native application. This integrates with Telco Cloud Automation and the Kubernetes clusters to simplify the requirements necessary to allow for Kubernetes to pull components from a secure Container Registry.
Harbor supports the Telco Cloud Platform by providing the following capabilities
Cloud-Native based deployment: The Container Registry provideds support for the self-healing capabilities of Kubernetes as well as being able to offer highly available models for the container registry in future releases.
Support for a modern cloud-native registry that supports both OCI images and the storing of HELM charts as OCI components.
Process Enhancements: built in processes for common activities such as Certificate replacement and storage expansion.
Telco Cloud Airgap Server : The Telco Cloud Airgap Server offers the capability for the operator to deploy and mange Kubernetes clusters with advanced configuration options without the requirement for external internet access.
For Telco workloads that require advanced configuration, such as Kernel revision changes, specific releases of DPDK or other kernel / OS related configuration these are dynamically added into the environment during workflow instantiation and are stored within the Airgap Platform.
The Airgap platform integrates with the Telco Cloud Platform and Telco Cloud Automation by securing the environment against internet access and also improving the deployment performance of kubernetes clusters.
The Airgap Server supports the Telco Cloud Platform by providing the following capabilities
Appliance based deployment for simple deployment onto the Telco Cloud management domain.
Support for tiered architectures to simplify the update / patching of the Telco Cloud environment,
Process Enhancements: built in processes for common activities such as Certificate replacement as well as integration to Telco cloud Automation for cascading changes across the Telco Cloud Platform.
Automation: The automation tooling comprises a number of components, from available SDKs / interfaces with modern programming languages as well as additional automation tooling appliances.
For Telco workloads that require advanced automation capabilities, Aria Automation Orchestrator can be integrated into the Telco Cloud Platform.
Aria Automation Orchestrator is an orchestration platform that closely integrates with both Telco Cloud Automation as well as the VIM layer (Cloud Director) and allows customers / tenants to create workflows to automate common actions.
Aria Automation Orchestrator is used to complement the functionality provided by the Workflow Hub component of the Telco Cloud Automation component,
The Automation Tooling supports the Telco Cloud Platform by providing the following capabilities
Simple Deployment: Appliance based deployment for simple deployment onto the Telco Cloud management domain, integration with the Load-Balancer to provide a highly available orchestration platform.
Workflow Library: Allows for the operator to leverage the built-in orchestration endpoints as well as leverage any pre-existing orchestration workflows that may exist from other network domains (such as the IT domain).
Telco Cloud Operations:
Platform Logging: Platform logging is an important element of the Telco cloud, the platform logging is responsible for logging and retaining / archiving all of the logging data from all components of the Telco Cloud Platform (including the applications if required). The platform logging should be able to collect security functions such as audit logs and changes to the platform.
The Platform logging of choice for the Telco Cloud Platform is Aria Operations for Logs, This component provides a highly scalable platform for logging data from all Telco Cloud resources, this can also capture logs from physical network devices and support the capabilities of log segmentation (user access) and log forwarding to external locations such as a SIEM platform.
In order to be efficient, the logging component should support the following advanced options to ensure optimal performance of all telco related workloads:
Scalable platform: Able to scale as the size of the Telco Cloud grows.
IPv6 capabilities: To support modern IP addressing requirements from Telco Customers
Strong AI / ML capabilities to simplify workflows and alerting
Support for all elements within the Telco Cloud from Physical to Service layers.
Platform Observability: Platform observability is an important elements of the Telco cloud, the platform observability is responsible for capturing platform wide metrics and creating dashboards, reporting and alerting to assist with operational issues.
The platform Observability should be able to cover all elements of the Telco Cloud, from the infrastructure layer, the CaaS layer and also includes the application level metrics,
The Platform Observability of choice for the Telco Cloud Platform is Aria Operations, This component provides a highly scalable platform for capturing all observability and metric related data across the entire Telco Cloud estate. The platform is extensible to support physical devices as well as the Telco Cloud components..
In order to be efficient, the observabilty component should support the following advanced options to ensure optimal performance of all telco related workloads:
Scalable platform: Able to scale as the size of the Telco Cloud grows, leveraging distributed architectures.
IPv6 capabilities: To support modern IP addressing requirements from Telco Customers
Strong AI / ML capabilities to simplify workflows and pro-active alerting.
Support for all elements within the Telco Cloud from Physical to Service layers.
Support for dashboard creation to customise based on customer requirements.
Network Inspection Tools: Network Inspection is an important elements for the Telco cloud, the network inspection tools are responsible for capturing network specific metrics as well as introducing support for physical network and firewalling platforms and the ability to trace network flows end-to-end.
The Network Inspection tools should be able to cover all elements of the Telco Cloud, from the infrastructure layer, the CaaS layer and physical layer from a networking perspective.
The Platform Observability of choice for the Telco Cloud Platform is Aria Operations for networks, This component provides a highly scalable platform for capturing all networking data across the entire Telco Cloud estate. The platform is extensible to support physical devices (Firewalls, Switches, Routers) as well as the Telco Cloud components..
In order to be efficient, the Network Inspection component should support the following advanced options to ensure optimal performance of all telco related workloads:
Scalable platform: Able to scale as the size of the Telco Cloud grows, leveraging distributed architectures.
IPv6 capabilities: To support modern IP addressing requirements from Telco Customers
Strong AI / ML capabilities to simplify workflows and pro-active alerting.
Support for all elements within the Telco Cloud from Physical to Service layers.
Support for dashboard creation to customise based on customer requirements.
Support for e2e packet tracing across SDN and physical neworking
Support for IPFIX ingestion and microsegmentation planning.
Telco Cloud Service Assurance: Service Assurance is a key elements for the Telco cloud, the Service Assurance elements is responsible for capturing applications specific metrics and data / logging to be able to perform service level monitoring and closed-loop remediation for 5G Core and RAN deployments.
The Service Assurance layer sits above platform observability, providing details and dashboard around network services, the metrics stretch across multiple layers from Optical, Physical networking, IP/MPLS layers to provide Assurance across multiple domains.
Telco Cloud Service Assurance. This component provides a highly scalable platform for capturing all networking data across the entire Telco Cloud estate. The platform is extensible to support physical devices (Firewalls, Switches, Routers) as well as the Telco Cloud components..
In order to be efficient, Telco Cloud Service Assurance supports the following advanced options to ensure optimal performance of all telco related workloads:
Scalable platform: Able to scale as the size of the Telco Cloud grows, leveraging distributed architectures.
IPv6 capabilities: To support modern IP addressing requirements from Telco Customers
Strong AI / ML capabilities to simplify workflows and pro-active alerting.
Support for all elements within the Telco Cloud across all domains
Support for dashboard creation to customise based on customer requirements.
Telco Cloud Bare Metal Automation: Bare Metal Automation offers an important component that allows for the bootstrapping (at large scale), automated deployment and configuration of the server hosts.
Bare Metal automation ranges from deployment of Guest Operating System platform to BIOS and Firmware configuration - to streamline the platform.
The Service Assurance layer sits above platform observability, providing details and dashboard around network services, the metrics stretch across multiple layers from Optical, Physical networking, IP/MPLS layers to provide Assurance across multiple domains.
Telco Cloud Service Assurance. This component provides a highly scalable platform for capturing all service data across the entire Telco Cloud estate.
In order to be efficient, Telco Cloud Service Assurance supports the following advanced options to ensure optimal performance of all telco related workloads:
Scalable platform: Able to scale as the size of the Telco Cloud grows, leveraging distributed architectures.
IPv6 capabilities: To support modern IP addressing requirements from Telco Customers
Strong AI / ML capabilities to simplify root-cause analysis and closed-loop remediation capabilities.
Support for all elements within the Telco Cloud across all domains
Support for dashboard creation to customise based on customer requirements.
Telco Cloud Use Cases
The Telco Cloud platform is built from a suite of components. The main offerings for the Telco Cloud are as follows:
Telco Cloud Platform Essentials
Telco Cloud Platform Advanced
Telco Cloud Platform RAN Essentials
Telco Cloud Platform - Centralized RIC (cRIC) with Service Management and Orchestration (SMO)
Each offering supports a range of use cases. This guide helps you understand the mapping between the Telco Cloud offerings and the operator use cases.
The offering and mapping are not strictly enforced. However, based on the different components between the Essentials and Advanced editions of Telco Cloud Platform, you can quickly get insights into benefits and use cases for the Advanced platform.
The following diagram illustrates the Telco Cloud Platform deployment models and their components.
Telco Cloud Platform Advanced includes the following additional capabilities over Essentials:
NSX Networking
Enhanced Data Plane Use Cases
T1 / T0 Routing
eVPN Architecture
VNF Integration with VMware Cloud Director™ and NSX
vSAN licensing (1 Tib per core in Advanced vs 100 Gib per core in Essentials based starting on vSphere 8.0U2)
VMware Telco Cloud Service Assurance™
Additional Telco Cloud Automation functionalities
CNF Onboarding, Design, and Lifecycle Management
Workflow Hub
Network Slicing
VMware Aria Operations™ for Networks
The workload capabilities available through Telco Cloud Platform Essentials are as follows:
TKG (CaaS) Cluster Deployment and CaaS Lifecycle Management (Including DIP Profiles)
VNF Onboarding and instantiation through TCA or VMware vCenter Server®
VNF Onboarding and Instantiation through VMware Cloud Director
Telco Cloud Platform Essentials does not include advanced networking configuration options available with NSX and as such supports only vSphere networking configurations. Additionally, Telco Cloud Platform Essentials supports CaaS cluster creation and lifecycle management, but does not support onboarding and instantiation of CNFs. VMware expects that all CNF LCM events are handled outside of TCA by third-party components.
The foundational elements of Telco Cloud Automation and vSphere, such as RBAC, Multi-Tenancy, and Kubernetes security configurations, remain the same in both Essentials and Advanced.
The following table outlines Telco Workload use cases and maps them to the Telco Cloud Platform Essentials and Advanced offerings.
NFs and Use Cases |
Workload Type |
Telco Cloud Platform Essentials |
Telco Cloud Platform Advanced |
Notes |
|---|---|---|---|---|
OSS / BSS without advanced networking |
VNF |
Yes |
Yes |
|
OSS / BSS with advanced networking |
VNF |
No |
Yes |
|
Cloud-Native OSS / BSS |
CNF |
No |
Yes |
CNF Onboarding and LCM are not available as part of Telco Cloud Platform Essentials |
VAS Services |
VNF |
Yes |
Yes |
|
Fixed Wireline Use Cases - Control Plane |
VNF |
Yes |
Yes |
Supported only with simple network architectures on Telco Cloud Platform Essentials |
Fixed Wireline Use Cases - Data Plane (CGNAT, BNG, vMCTS, and so on) |
VNF |
Yes |
Yes |
Low-Medium throughput and Scale use cases |
Fixed Wireline use cases - Data Plane (CGNAT, BNG, and so on) |
VNF |
No |
Yes |
Medium-High throughput and Scale use cases leveraging EDP |
5G SA / DM Core |
CNF |
No |
Yes |
|
5G Core supplemental applications |
CNF |
No |
Yes |
|
4G Legacy user-plane workloads |
VNF |
No |
Yes |
|
4G Legacy control-plane workloads |
VNF |
Yes |
Yes |
Telco Cloud Platform Essentials as an architecture supports predominantly VNF workloads without complex networking and Caas Management. CNF onboarding and instantiation are not available as part of Essentials.
The following diagram illustrates the workload supported in Telco Cloud Platform Advanced. Telco Cloud Platform provides a deeper integration between TCA and Cloud Director, and additional functionalities on the CaaS and CNF Management segment.
Telco Cloud Platform additionally encompasses RAN deployment models. Similar to Telco Cloud Platform Essentials and Advanced, Telco Cloud Platform RAN supports two main offerings in the RAN scenario.
The following diagram illustrates the Telco Cloud Platform RAN deployment models.
Similar to Telco Cloud Platform Essentials, Telco Cloud Platform Essentials for RAN focuses on Caas Cluster deployment and LCM. The Telco Cloud Platform Essentials for RAN platform does not include Telco Cloud Service Assurance and the instantiation and LCM of CNFs.
vSphere, TKG-M, and Aria Suite components are not part of the Centralized RIC with SMO, but they constitute the IaaS, CaaS, and O-Cloud layers of Telco Cloud Platform Essentials for RAN.
The following table outlines various RAN workload use cases and maps them to Telco Cloud Platform Essentials for RAN and cRIC+SMO offerings. The placement of the DU and CU in Distributed RAN (D-RAN) and Centralized RAN (C-RAN) does not impact this mapping.
NFs and Use Cases |
Workload Type |
Telco Cloud Platform Essentials RAN |
cRIC + SMO |
Notes |
|---|---|---|---|---|
Caas Management Only |
N/A |
Yes |
Yes |
Cluster Creation (inc Infra Profiles) |
DU Workloads |
CNF |
No |
Yes |
CNF Instantiation and LCM |
CU Workloads |
CNF |
No |
Yes |
CNF Instantiation and LCM |
Legacy VNFs illustrated in this diagram are not using NSX. If the legacy VNFs require NSX for advanced networking, or if the deployment architecture leverages NSX, then Telco Cloud Platform also require TCA Advanced configuration.
This diagram does not show a converged management domain that hosts components for managing non-Telco workloads.
Multi-Tier and Distributed Architecture
VMware Telco Cloud is a common platform from Core to RAN. This common platform can adapt and scale automatically depending on the workload deployed through VMware Telco Cloud Automation™.
To deploy all workload types such as VNFs and CNFs from 4G and 5G Core to RAN (including 4G Control functions, 4G EPC functions, 5G Core functions, and RAN DU/CU functions), the same infrastructure components, automation platforms, operational tooling, and CaaS infrastructure is leveraged end-to-end.
The 5G network must be dynamic and programmable to achieve business objectives. Network operators must be able to provision virtual network slices on-demand with QoS. This helps meet SLAs, provision functions to increase capacity using industry-standard APIs, and re-route traffic during congestion proactively and securely.
To handle the massive data traffic, 5G is designed to separate the user plane from the control plane and to distribute user plane functions as close to the end-user device as possible. As the user traffic increases, operators can add more user plane services without changing the control plane capacity. This distributed architecture can be realized by building the data center and network infrastructure based on hierarchical layers. The following diagram illustrates a hierarchical 5G design.
Applications such as RAN cell sites, sensors, and smart devices can reside on the network edge.
Far Edge: The network far edge is the aggregation point for the geographically distributed radio sites hosting RAN and IP routing aggregators. It might also host mobile edge computing software to support private 5G use cases for factory automation, remote presence, and so on. Access mobility and user plane termination functions of the 5G core can also reside on the far edge. The type and number of applications that can be hosted on the far-edge sites are limited by available power and space.
Near Edge: The near edge is the aggregation point for far edge sites. It hosts many of the services as the far edge. It also serves as a peering point to access the Internet or other infrastructure-related cloud services. In a distributed 5G Core, the UPF can be deployed at the near edge for distributed break-out points for efficient internet and off-ramp connectivity.
The central or core sites host infrastructure components such as the VMware Telco cloud management components, Kubernetes Management clusters, CICD toolchains, Operational Support Systems (OSS), Observability platforms, Kubernetes image repository, and so on.
Depending on the 5G deployment, control plane functions of the 5G core, subscriber database, and so on can reside in the core or regional data center.
RAN Architectures
The RAN network must adhere to the multi-tier and distributed architecture of the 5G Core and the specifications of the RAN environment.
The model of the Telco Cloud architecture allows CSPs to scale 5G deployments based on application requirements and user load. Modern Telco architecture consists of four levels: 5G subscriber databases, data repositories, resource orchestration, and service assurance are typically hosted in the Central, or core data centers. The central and regional data centers also serve as peering points for lawful intercept points. For redundancy, a pair of central data centers are deployed in geographically diverse sites.
In this diagram, the regional or domain data centers host the 5G core user plane function, voice services functions, and non-call processing infrastructure such as IPAM, DNS, and NTP servers. Inbound and outbound roaming traffic can also be routed from the regional data center to the edge. With the inclusion of RAN and CRAN / DRAN, the distribution of user plane functions becomes more visible.
The Telco Cloud Platform is a compute workload domain that can span from the Core and Regional / Domain Data Centers to individual cell sites.
DRAN architecture: The Cell site uses the Distributed RAN (DRAN) architecture. This architecture uses single hosts, distributed across thousands of remote cell sites. However, more complex architectures for cell sites (with redundancy) can be used.
CRAN architecture: Near-edge sites can implement a Centralized RAN (CRAN) architecture. This architecture uses a cluster of hosts for high availability, resiliency, and scale. In the CRAN model, RAN functions are deployed outside of the cell sites.
For more information about these two architectural models, see Telco Cloud - RAN Domains.
To support new applications and devices that require ultra-low latency, localized processing, and high-throughput networks, CSPs can push the 5G user plane closer to the application edge. At the same time, RAN dis-aggregation enables efficient hardware utilization and pooling gain and increases deployment flexibility while reducing the Capital Expenditure (CAPEX) and Operational Expenditure (OPEX) of Radio Access.
The core sites (Central, Regional, and Edge sites) are part of the 5G Core architecture, while the far edge or cell sites are also commonly part of the RAN architecture for CRAN and DRAN.
5G Service-Based Architecture
5G comes with the specification of a Service-Based Architecture (SBA). The basic principles of SBA are independent of vendors, products, and technologies. A service is a discrete unit of functionality that can be accessed remotely, acted upon, and updated independently. SBAs improve the modularity of products. The network functions creating the 5G service can be categorized into communicating services. With this approach, users can deploy services from different vendors into a single product.
The following diagram illustrates various 5G Core Control Plane functions. The UPF and RAN components are User Plane Functions responsible for radio control, packet routing, Deep Packet Inspection (DPI), and other router-based functions.
Containers are used as a portable and lightweight virtualization solution for 5G Service-Based Architecture (SBA). Kubernetes is one of the components to consider when delivering Carrier-Grade Container as a Service (CaaS). 5G Core network functions are deployed in a cloud-native form although VM-based components can also exist.
A Carrier-Grade CaaS platform requires a complex ecosystem of solutions and functions to form a pre-set business and operating model. The cloud infrastructure modernization changes not only the business model in service agility and metered revenue models but also challenges the silo operating model.
5G Core and RAN Connectivity Considerations
The following core and edge connectivity considerations are required to support different deployment models of 5G RAN:
Core and Edge connectivity: Core and Edge connectivity have a significant impact on the 5G core deployment and it provides application-specific SLAs. The radio spectrum type, connectivity, and available bandwidth also have an impact on the placement of CNFs.
WAN connectivity and Bandwidth: In the centralized deployment model, the WAN connectivity must be reliable between the sites. All 5G control traffic travels from the edge to the core, so any unexpected WAN outage prevents 5G user sessions from being established.
The fronthaul traffic forwarding from the Remote Radio Unit (RRU) to the DU can be significant in a C-RAN environment, so appropriate bandwidth and infrastructure sizing are required. The WAN sizing and redundant connectivity requirements must be based on the maximum expected throughput, as required Quality of Service (QoS) can be deployed to protect high-priority traffic between the RAN and Far Edge / Core sites.
Components deployment in Cell Site: Due to the physical constraints of remote Cell Site locations, deploy only the required functions at the Cell Site and the remaining components centrally. For example, observability and logging functions are often deployed centrally to provide universal visibility and control. Non-latency-sensitive user metrics are often forwarded centrally for processing.
Network Routing and Local Break-out: Each cell site or far-edge site routes the user plane and Internet traffic through the local Internet gateways, while the device communication involving management and non-real-time sensitive applications leverages the core.
