What is a Packet Core Network Engineer?

What technical knowledge should I have to get an entry-level job as a Packet Core Network Engineer?

I often get asked this question by many fresh graduates, interns or people in telecom field who want to shift their domain to Packet Core Network.

First, here is a brief summary, Packet Core Network (or PS Core Network) is a part of Mobile Network Architecture responsible for providing data services to mobile users/devices. The most popular data service is "Access to Internet".

Packet Core Network Engineer is responsible for design, planning, deployment, maintenance, troubleshooting, and optimization of Packet Core Network (sometimes a Packet Core Engineer can focus only on some of the aforementioned roles, and then it can be named accordingly such as Packet Core Planning Engineer, Packet Core Operation Engineer or Packet Core Optimization Engineer).

Second, here are some pointers of what technical knowledge you need to have from my experience:

Packet Core Network Architecture

Knowledge about Mobile Network architecture in general (2G/3G/4G/5G), and especially Packet Core Network architecture (GPRS/EPC/5GC), its network elements' functions, procedures and protocols in details.

Routing and Switching

As a Packet Core Engineer, you will spend a lot of time working with IP/datacom engineers to establish/troubleshoot IP connectivity of Packet core nodes. So good Routing and Switching knowledge (TCP/IP, VLAN, subnetting, static routing and dynamic routing protocols) will make communication and collaboration more effective and efficient.

Network Function Virtualization (NFV)

NFV is nothing but the implementation of "Cloud Computing" technologies in the Telecom field. Nowadays, the use of dedicated Packet Core appliances is fading in favour of deploying Packet Core nodes over cloud infrastructure as it brings superior flexibility/reliability advantages. Such knowledge is necessary in scenarios where Packet Core Engineers are responsible for the management and deployment of NFV infrastructure, or they are heavily involved in collaborating with other engineers who do.