For communications service providers that are opening their radio access networks, RAN, to better support 5G, the hypervisor is the unheralded workhorse. Though it's often removed from the center of attention or overlooked entirely by bare-metal enthusiasts, it supplies the underlying foundation for building a flexible open RAN. The benefits of the hypervisor are multi-faceted:
- Supports disaggregation of the RAN in a multi-vendor network
- Enables multiple workloads on the same COTS hardware and multiple versions of operating systems
- Provides agility and automation to reap the full potential of new 5G revenue stream
- Supports high performance and low latency for telecom workloads
- Improves security for containerized workloads
An open RAN seeks to adopt the industry trajectory toward virtualization, software-defined networking, and network programmability. Indeed, 5G standards herald a cloud-native future, and part of that future lies in a vision to disaggregate the RAN and introduce RAN intelligent controllers that power network programmability.
But there's more: Virtualization and software-defined networking let you replace costly, purpose-built RAN hardware with cheaper commodity servers.
Consolidation on the common, shared hardware layer created by hypervisors improves utilization and increases efficiency. The software-defined nature of virtual machines (VMs) lets you manage your RAN stack with more agility, manage the functions at scale from a central location, and automate elasticity and security.
From Guiding Principles to a Multi-Vendor Reality
The hypervisor supplies the infrastructure that can be used now to support multiple vendors and extract your operations from the lock-in trap of a closed monolithic stack. Similarly, security is improved in multi-vendor networks as problems of using a single-vendor RAN stack are compounded if the components are closed systems without software transparency and without rapid announcements of discovered security vulnerabilities and their patches.
Multi-vendor environments that flourish through the adoption of standardized open interfaces and the resulting interoperability can lead to better protected environments and more secure telecommunications infrastructure, so much so that federal governments are beginning to either require or support multi-vendor environments. Emerging 5G security standards like the telecom security requirements, or TSRs, from the U.K.'s Center for Cyber Security (NCSC) require the use of multiple vendors.
Flexible Workload Workhorse
The hypervisor is also the underlying workhorse that lets you run and easily manage multiple workloads on the same hardware, and you can use different operating systems to support different network functions.
RAN workloads have stringent performance requirements measured in microseconds. The VMware hypervisor, VMware ESXi, has been optimized to remove jitter and meet the demanding requirements of RAN applications. VMware Telco Cloud Platform RAN, for instance, optimally allocates CPU, memory, and device resources on the same NUMA node to support performance-sensitive workloads. The VMware hypervisor uses the Precision Time Protocol (PTP) to meet the levels of accuracy required by RAN.
High Performance and Low Latency for RAN Workloads
But some contrarians might pose the question: Isn't there a performance tax for real-time RAN workloads on vSphere? The answer is no. VMware ran industry-standard real-time micro-benchmarks, namely cyclictest and oslat, to compare the performance of RAN workloads on vSphere and bare metal and found that performance is equivalent.
In addition to performance, operating CNFs in production requires security, lifecycle management, high availability, resource management, data persistence, networking, and automation ─ all of which are an integral part of vSphere and the VMware Telco Cloud.
Management and Automation
The management and automation capabilities of using hypervisors and VMs can significantly reduce the pain and problems that come with trying to use bare metal. With ESXi 7.0U3, you can, for instance, manage the NIC firmware and image directly. With VMware Telco Cloud Automation, late binding of node configurations can be accomplished with IPv6 support. The platform also optimizes the performance of large Kubernetes clusters and mixed workloads. Programmable resource provisioning optimizes the placement of 5G services, CNFs, CUs, and DUs, to maximize resources and RAN performance.
Boosting performance by selecting a Linux kernel version
With containers, a crucial factor is the version of the container host's kernel and its performance characteristics. Another performance advantage of running containers on virtual machines is that you can not only easily select the container host that you want to use but also maximize the CPU resources of the underlying hardware by running multiple VMs, each with its own choice of container host.
Conclusion
- Scale CNFs without the pain of adding, configuring, or managing physical hardware
- Select the best Linux kernel version for your workload
- Optimize the performance of large Kubernetes clusters and mixed workloads on shared infrastructure
- Automate lifecycle management of Kubernetes clusters, network functions, and 5G services
In a word, hypervisors are optimally designed to help you reap the full potential of new revenue streams in the 5G era.