Exchange Online & Teams Migration
Migration of a business-critical messaging platform to a cloud-based architecture with voice integration
Problem
The company was running aging on-premises messaging and telephony infrastructure approaching end of support. The fragmented setup created operational overhead and limited scalability.
Approach
Two-phase migration strategy — telephony first, mailboxes second (smaller blast radius, builds operational confidence before the larger migration):
- Teams Calling — Direct Routing with SBC high availability (chosen over Calling Plan for cost control, number portability, and leverage of existing SBC investment)
- Exchange Online — Bridge architecture for hybrid coexistence (enables staged migration with zero downtime while maintaining mail flow between on-premises and cloud)
- Public folders — Modernized and migrated using PowerShell automation pipeline
- Security uplift — License upgrade for advanced threat protection (ATP, Attack Simulation, Safe Attachments/Links)
Key Challenges Solved
- Voice interoperability — IVR compatibility issues resolved through media bypass and early media configuration adjustments
- Hybrid coexistence — Bridge-based migration with proper mail flow connectors and email authentication (SPF/DKIM/DMARC)
- Provider evaluation — Structured evaluation of SIP trunk providers considering number portability risks
Outcome
- Complete migration with zero downtime — Enterprise-wide transition to Exchange Online and Teams with uninterrupted operations
- Unified communication platform — Messaging, telephony, and collaboration consolidated on a single platform
- Improved security posture — Advanced Threat Protection, Attack Simulation, and Safe Attachments/Links enabled enterprise-wide
- Carrier independence — Direct Routing enables flexible provider switching without platform changes
Hybrid Identity & User Lifecycle Automation
Fully standardized employee onboarding and offboarding automation
What It Does
- Self-service portal — HR-initiated provisioning via a low-code portal
- On-premises orchestration — PowerShell pipeline for Active Directory account provisioning, fileshare permissions, and cloud group memberships
- Cloud onboarding — Automatic mailbox configuration, licensing, and phone number assignment via Azure Automation and Graph API
- Lifecycle management — Standardized onboarding and offboarding process across all IT systems, triggered by a single HR action
Centralized Log Aggregation and Anomaly Detection
Enterprise-wide SIEM platform with Elastic Stack
Problem
Security-relevant events — failed logins, account lockouts, authentication attempts, application errors — were scattered across the entire server fleet with no way to correlate or alert on patterns. Threats like password spray attacks were invisible without centralized visibility.
What It Does
- Infrastructure — Elasticsearch-Logstash-Kibana cluster in high availability configuration
- Data ingestion — Multi-source collection: application logs, performance metrics, Windows events, and uptime monitoring
- Security dashboards — Correlation of account lockouts with failed login patterns for real-time detection of password spray attacks, brute force attempts, and anomalous authentication behavior
- Operational monitoring — Performance metrics, uptime monitoring, and compliance reporting across the full server fleet
Outcome
- Centralized security visibility — From scattered, uncorrelatable logs to enterprise-wide real-time threat detection
- Automated detection — Password spray attacks, brute force attempts, and anomalous authentication behavior detected in real time
- Operational transparency — Correlation of performance data, availability, and security events across the entire infrastructure