5G Core implementation: Challenges in the field

With an emerging demand for higher speeds, lower latency, and increasing connection density,  telecommunications providers have started implementing 5G. While the initial roll-out usually takes months, the entire process is going to take years. This is because designing and implementing 5G entails a number of challenges. These include deployment and operations of the physical infrastructure and VNFs (Virtual Network Functions) onboarding and orchestration. In this blog, we present the benefits of using Juju charms for 5G Core implementation purposes. It is shown how the aforementioned challenges can be overcome. Finally, we demonstrate how a telco can implement 5G Core with Juju charms, using BT as an example.

Challenges related to NFV adoption

Adopting NFV (Network Functions Virtualisation) requires implementing the following two layers: NFVI (NFV Infrastructure) and MANO (MANagement and Orchestration). According to the OPNFV (Open Platform for NFV) architecture, NFVI is usually deployed based on OpenStack which provides the cloud IaaS (Infrastructure-as-a-Service) functionality and / or Kubernetes – a container orchestration platform. These solutions, however, are known from being difficult to deploy and operate, especially in distributed environments consisting of hundreds of nodes. Moreover, telco use cases usually require certain extensions, such as complex SDN (Software Defined Networking) or DPDK (Data Plane Development Kit), to be enabled which makes the whole process even harder.

With regards to MANO, contrary to early generations of NFV technology, 5G brings in specific requirements for VNFs onboarding and orchestration. Instead of just running legacy monolithic software blocks in a virtualised environment, 5G VNFs are going to be fully cloud-native. This means that they have to be re-designed based on a microservices architecture. Those microservices will later run inside highly available and massively scalable VMs or containers, which introduces another layer of complexity over the already complex cloud environment.

Using Juju charms for 5G Core implementation

In order to satisfy the demanding requirements for service orchestration and lifecycle management, Canonical has developed Juju – an application modelling tool. Juju uses charms – a collection of scripts and metadata – which contain all necessary logic required to install, configure and operate applications. By using charms for 5G Core implementation purposes, telcos can benefit from a full automation, declarative DevOps approach and facilitated operational tasks, such as upgrades or backups. All of those operations are managed by the Juju controller. Combining it with other Canonical’s open-source tools helps to reduce the time required to deploy 5G Core from months to days.

As stated in the previous section, an open source NFVI is usually implemented based on OpenStack and Kubernetes. Canonical provides both Charmed OpenStack and Charmed Kubernetes, which allows both platforms to be deployed with charms. This means telcos can just model their NFVI by creating a YAML file in which it is possible to:

• define the number of machines being deployed
• define the desired SDN solution to be used
• add or remove certain services (such as monitoring)
• turn on / off certain features (such as DPDK).

The rest of the work is done by the charms under the control of Juju. Moreover, daily operational tasks, such as OpenStack upgrades, can be also performed by just launching an action against the Juju controller. This is a huge improvement compared to legacy deployment methods and operations tools based on custom scripts and imperative playbooks.

With regards to the MANO layer, Canonical provides OSM (Open Source MANO) which delivers an open source stack aligned with ETSI NFV Information Models. The whole OSM stack can again be deployed by Juju on top of a Kubernetes cluster, but the OSM itself also uses charms for VNFs onboarding and orchestration, including all DayN configuration tasks.

Use case: BT

In order to overcome the challenges associated with 5G Core implementation, BT, one of the biggest telcos in Europe, has recently turned to Canonical.. Having years of experience in private cloud deployments, Canonical will not only provide BT with the basis of a cloud but also help them to spread the power of Juju across their telco-specific use cases. By utilising Juju for NFVI deployment purposes, BT is aiming to use it as an NFVI / VIM (Virtual Infrastructure Manager) installer.

To build NFVI for their 5G Core, BT will use Charmed OpenStack and Canonical’s open source tools to automate the deployment and operations. The whole stack includes MAAS for bare metal provisioning, Ubuntu Server LTS as the operating system, Juju for application modelling and orchestration, LXD for control services containerisation, and various charmed applications. Charms will be used to deploy not only OpenStack, but also a variety of supporting services, such as the whole logging and monitoring stack.

Conclusions

Implementing and operating the 5G core is a challenging and complex task. However, by using charms, the entire complexity gets relaxed allowing telcos to focus on implementing VNFs rather than the 5G Core itself.

For more information about Canonical solutions for telecommunications visit our NFV website.