Network Deployment Phases
Reference description of the standard phases in a network infrastructure deployment program, from initial discovery through post-deployment operations handover.
Contents
Phase 1: Discovery and Assessment
Discovery establishes the current state of existing infrastructure and the requirements for the new deployment. Activities include physical site surveys (telecommunications room conditions, cable pathway availability, electrical capacity, cooling adequacy), logical network assessment (current addressing scheme, VLAN design, routing protocols), inventory of existing equipment (model, age, firmware version, support status), and application requirements gathering from key application owners. Discovery outputs form the technical basis for design decisions in the next phase.
Phase 2: Design
Design translates discovery findings and requirements into detailed technical specifications. A comprehensive network design package includes: physical topology diagram showing equipment placement and cable runs, logical topology showing switching hierarchy, VLAN structure, and routing design, IP addressing plan, security policy definition (network segmentation, access control lists, firewall rules), management and monitoring architecture, and high-availability design with failover behaviour documented. Design review by a second engineer before approval reduces the probability of implementation issues caused by design errors.
Phase 3: Procurement
Infrastructure procurement lead times for network equipment range from a few weeks for catalogue items to several months for custom configurations or during periods of supply constraint. Initiating procurement immediately after design approval reduces total program duration. Verify that all ordered equipment is on the approved hardware list for the software versions and features required by the design. Document the procurement schedule and identify long-lead items early so the program plan can account for their delivery timing.
Phase 4: Installation and Configuration
Physical installation covers equipment mounting, cabling, power connection, and labelling. Configuration applies the technical design to each device: hostname, management access, VLAN configuration, routing, security policies, and management platform registration. Configuration should be applied from a standardized template rather than manually configured device by device, reducing configuration inconsistencies. Record all configuration changes in change management documentation. Photograph equipment installations for the as-built documentation package.
Phase 5: Testing and Validation
Testing verifies that the deployed infrastructure operates according to the design specifications before cutover affects production services. Test categories include: connectivity tests (verify expected layer 2 and layer 3 reachability between all required endpoints), performance tests (verify throughput meets requirements for critical paths), failover tests (verify that redundancy mechanisms operate correctly by simulating individual component failures), and application tests (verify that key applications function correctly through the new infrastructure in a pre-production environment). Document all test results and sign off on test completion before initiating cutover.
Phase 6: Cutover
Cutover migrates production services from existing to new infrastructure. Cutover planning defines the sequence of services to migrate, the rollback procedure if critical issues are encountered, the communication plan for affected users and application teams, and the monitoring approach during and after cutover. For large-scale deployments, phased cutover (migrating by floor, building, or business unit) reduces the blast radius of any issue encountered and allows the implementation team to refine procedures between cutover events.
Phase 7: Operations Handover
Operations handover transfers responsibility for ongoing management of the deployed infrastructure from the implementation team to the operations team. Handover documentation includes: as-built topology diagrams updated to reflect the actual deployed configuration, device inventory with serial numbers, support contract details, and firmware versions, runbooks for common operational tasks, and escalation contacts for vendor support. A structured handover knowledge transfer session reduces the learning curve for the operations team and identifies any operational procedures that require further documentation before the implementation team disengages.