Investigate the critical role of cybersecurity in ensuring the integrity, confidentiality, and availability of telecommunications networks and data communications. Discuss common threats and vulnerabilities faced by telecommunications systems, including malware, phishing, and denial$-$of$-$service attacks. Explore techniques for securing network infrastructure, such as encryption, authentication, access control, and intrusion detection$/$prevention systems. Analyze case studies of notable cyber attacks on telecommunications networks and the lessons learned for improving cybersecurity practices in the field.