Dimensioning Challenges of Telecommunication Network Elements Migrating Onto the Cloud (Invited Paper)

The excursion on the long road of telecommunications is continuously evolving. Newer mobile generations, optimizations, modernizations, technology changes, and various mergers have been experienced in the past decades. Different drivers continuously shift physical network elements towards software (SW) only deployments in all IP telecommunication networks. The decoupling of application SW from hardware (HW) is accelerated by virtualization. The ‘cloudification’ of legacy telecommunication equipment made communication networks not only more flexible, but also opened new doors. Brand new services became available thanks to the ongoing fusion of two domains: telecommunications and IT (Information Technology). A new era called ‘Telco-Cloud’ was born. One original goal was to use commercial IT computing servers as HW platform hoping cost efficiency. Another expected benefit was the prompt use of existing experience in the operation and maintenance of IT HW in Data Centers. More and more network functions are virtualized on top of IT HW nowadays. However, the strict requirements of the legacy-Physical Network Function (PNF) based-telecommunications mandate special configurations and practices on cloud. The rapidly increasing amount of Virtual Network Functions (VNFs) and Cloud-native Network Functions (CNFs) introduces new concepts for dimensioning, deployment, operation, management, and monitoring. Some availability and operability requirements and expectations are inherited from the legacy PNF domain, meanwhile the telecommunication world itself undergoes a continuous change towards Telco-Cloud and 5G/6G. This paper overviews the evolution steps to Telco-Cloud. The challenges in the dimensioning and availability design are discussed, and some concepts and examples are presented on NF and network levels.