Develop a comprehensive disaster recovery plan for your communications infrastructure. Identify critical components such as [VoIP Servers], [PBX Systems], and [Internet Connectivity], and assess the impact of each on your operations. Define recovery time objectives (RTO) and recovery point objectives (RPO) for each critical component, and develop a step-by-step recovery procedure that ensures minimal disruption to communications during a crisis. Include key contacts and backup resources, such as alternative service providers or equipment suppliers.