7.1 Migration Strategy Overview¶
7.1.1 Executive Summary¶
Migration Program Overview¶
migration_program:
name: "Abhavtech SD-WAN Transformation"
objective: "Migrate from legacy MPLS WAN to Cisco Catalyst SD-WAN"
current_state:
wan_technology: "MPLS"
monthly_cost: "$XX,XXX"
sites: 9
circuits: 18 (primary + backup per site)
pain_points:
- "High MPLS costs"
- "Long provisioning times (45-60 days)"
- "Limited application visibility"
- "No direct internet access"
- "Complex multi-vendor management"
target_state:
wan_technology: "Cisco Catalyst SD-WAN"
projected_monthly_cost: "$XX,XXX"
transport_diversity: "MPLS + Internet + 5G/LTE"
benefits:
- "40% cost reduction"
- "Application-aware routing"
- "Direct internet access"
- "Centralized management"
- "SD-Access fabric integration"
timeline:
total_duration: "16 weeks"
phases: 4
target_completion: "Q2 2025"
Key Success Factors¶
success_factors:
executive_sponsorship:
importance: "Critical"
sponsor: "CTO"
involvement: "Weekly steering committee"
business_continuity:
importance: "Critical"
approach: "Zero production outage tolerance"
validation: "Pre-migration testing"
stakeholder_alignment:
importance: "High"
stakeholders:
- "IT Operations"
- "Application Teams"
- "Security Team"
- "Business Units"
communication: "Weekly updates"
technical_readiness:
importance: "High"
requirements:
- "SD-Access fabric operational"
- "Controller infrastructure deployed"
- "Team training completed"
change_management:
importance: "High"
process: "ITIL-aligned"
cab_approval: "Required for all migrations"
7.1.2 Migration Approach¶
Phased Migration Strategy¶
migration_phases:
phase_1_foundation:
name: "Foundation & Pilot"
duration: "Weeks 1-4"
objectives:
- "Deploy controller infrastructure"
- "Configure templates and policies"
- "Migrate pilot site"
- "Validate integration with SD-Access"
sites:
- "Bangalore Branch (pilot)"
success_criteria:
- "Controllers operational"
- "Pilot site fully functional"
- "No production impact"
phase_2_branch_rollout:
name: "Branch Site Migration"
duration: "Weeks 5-8"
objectives:
- "Migrate remaining branch sites"
- "Establish hub connectivity"
- "Enable application policies"
sites:
- "Delhi Branch"
- "Noida Branch"
- "Frankfurt Branch"
- "Dallas Branch"
success_criteria:
- "All branches migrated"
- "Application performance validated"
- "User acceptance confirmed"
phase_3_hub_migration:
name: "Hub Site Migration"
duration: "Weeks 9-12"
objectives:
- "Migrate hub sites with full redundancy"
- "Establish SD-Access fabric handoff"
- "Enable advanced features"
sites:
- "Chennai Hub"
- "London Hub"
- "New Jersey Hub"
success_criteria:
- "Hub sites migrated"
- "SD-Access integration verified"
- "Full mesh established"
phase_4_primary_hub:
name: "Primary Hub & Optimization"
duration: "Weeks 13-16"
objectives:
- "Migrate Mumbai primary hub"
- "Full MPLS decommissioning"
- "Performance optimization"
sites:
- "Mumbai Hub"
success_criteria:
- "All sites on SD-WAN"
- "MPLS circuits decommissioned"
- "Cost savings realized"
Migration Principles¶
migration_principles:
business_first:
description: "Business continuity above all"
implementation:
- "Zero tolerance for production outages"
- "Rollback procedures ready"
- "Fallback to MPLS always available"
gradual_cutover:
description: "Progressive traffic migration"
implementation:
- "Dual-stack during migration"
- "Traffic engineering for controlled cutover"
- "Monitor before full cutover"
validate_before_proceed:
description: "Thorough validation at each step"
implementation:
- "Defined acceptance criteria"
- "Stakeholder sign-off"
- "Performance baseline comparison"
automation_first:
description: "Automate where possible"
implementation:
- "Template-based deployment"
- "Automated testing"
- "Scripted validation"
7.1.3 Site Migration Sequencing¶
Migration Order Rationale¶
migration_sequencing:
sequencing_criteria:
business_criticality:
weight: 30
consideration: "Migrate lower-risk sites first"
technical_complexity:
weight: 25
consideration: "Simple sites before complex"
geographic_distribution:
weight: 20
consideration: "Spread across regions"
sd_access_integration:
weight: 15
consideration: "Sites with fabric handoff later"
circuit_readiness:
weight: 10
consideration: "Internet circuit availability"
site_prioritization:
tier_1_pilot:
sites: ["Bangalore"]
characteristics:
- "Medium criticality"
- "Low complexity"
- "Good fallback options"
- "Experienced local IT support"
timeline: "Week 3-4"
tier_2_branches:
sites: ["Delhi", "Noida", "Frankfurt", "Dallas"]
characteristics:
- "Standard branch configuration"
- "No fabric handoff"
- "Single/dual WAN Edge"
timeline: "Weeks 5-8"
tier_3_regional_hubs:
sites: ["Chennai", "London", "New Jersey"]
characteristics:
- "Hub configuration"
- "Fabric handoff (Chennai)"
- "Dual WAN Edge HA"
timeline: "Weeks 9-12"
tier_4_primary_hub:
sites: ["Mumbai"]
characteristics:
- "Primary hub"
- "Full fabric handoff"
- "Maximum complexity"
- "Highest criticality"
timeline: "Weeks 13-16"
Site Migration Topology¶
MIGRATION SEQUENCE TOPOLOGY
===========================
Phase 1 (Pilot):
+-------------------+
| Mumbai Hub |
| (MPLS Only) |
+--------+----------+
|
| MPLS
|
+--------v----------+
| Bangalore Branch |
| (SD-WAN Pilot) |
+-------------------+
Phase 2 (Branch Rollout):
+-------------------+
| Mumbai Hub |
| (MPLS + SD-WAN) |
+--------+----------+
|
+--------------+--------------+
| | |
+----v----+ +-----v-----+ +----v----+
| Delhi | | Noida | | Frankfurt|
| SD-WAN | | SD-WAN | | SD-WAN |
+---------+ +-----------+ +----------+
Phase 3-4 (Hub Migration):
+-------------------+
| Mumbai Hub |<----+
| SD-WAN Primary | |
+--------+----------+ |
| |
+--------------+----+----+-----+
| | | |
+----v----+ +-----v-+ | +-v-------+
| Chennai | | London| | |New Jersey|
| SD-WAN | | SD-WAN| | | SD-WAN |
+---------+ +-------+ | +---------+
| |
v v
[SD-Access [Branch Sites]
Fabric]
7.1.4 Risk Management¶
Migration Risk Register¶
risk_register:
high_risks:
risk_001:
name: "Production outage during migration"
probability: "Medium"
impact: "Critical"
mitigation:
- "Maintain MPLS throughout migration"
- "Extensive pre-migration testing"
- "Defined rollback procedures"
- "Maintenance window execution"
owner: "Project Manager"
risk_002:
name: "Application performance degradation"
probability: "Medium"
impact: "High"
mitigation:
- "Baseline performance before migration"
- "Configure application-aware routing"
- "Monitor during and after migration"
- "Quick rollback capability"
owner: "Network Lead"
risk_003:
name: "SD-Access integration failure"
probability: "Low"
impact: "High"
mitigation:
- "Pre-validate in lab environment"
- "Staged integration approach"
- "Cisco TAC engagement"
owner: "Integration Lead"
medium_risks:
risk_004:
name: "Circuit provisioning delays"
probability: "High"
impact: "Medium"
mitigation:
- "Order circuits 8 weeks ahead"
- "Track provisioning status"
- "Have backup provider options"
owner: "Procurement"
risk_005:
name: "Skills gap in operations team"
probability: "Medium"
impact: "Medium"
mitigation:
- "Training before migration starts"
- "Cisco partner support during migration"
- "Knowledge transfer sessions"
owner: "Training Lead"
risk_006:
name: "Controller capacity insufficient"
probability: "Low"
impact: "Medium"
mitigation:
- "Right-size controller deployment"
- "Monitor controller resources"
- "Scale-up plan ready"
owner: "Architecture Lead"
Risk Response Matrix¶
risk_response:
production_impact:
trigger: "User-reported issues or monitoring alerts"
immediate_actions:
- "Assess impact scope"
- "Engage on-call engineer"
- "Prepare rollback if needed"
escalation_path:
15_minutes: "Project Manager"
30_minutes: "IT Director"
60_minutes: "CTO"
migration_failure:
trigger: "Site migration does not complete successfully"
immediate_actions:
- "Execute rollback procedure"
- "Document failure details"
- "Root cause analysis"
escalation_path:
immediate: "Project Manager"
next_day: "Steering Committee"
vendor_issues:
trigger: "Cisco TAC or partner escalation required"
immediate_actions:
- "Open TAC case"
- "Provide all diagnostic data"
- "Engage partner account team"
escalation_path:
24_hours: "Partner escalation"
48_hours: "Cisco account team"
7.1.5 Governance Structure¶
Project Organization¶
project_governance:
steering_committee:
chair: "CTO"
members:
- "IT Director"
- "Network Manager"
- "Security Manager"
- "Business Representatives"
meeting_frequency: "Weekly"
responsibilities:
- "Strategic decisions"
- "Budget approval"
- "Risk acceptance"
- "Go/No-go decisions"
project_team:
project_manager:
responsibilities:
- "Overall project delivery"
- "Timeline management"
- "Stakeholder communication"
- "Risk management"
technical_lead:
responsibilities:
- "Technical design"
- "Migration execution"
- "Problem resolution"
- "Team coordination"
network_engineers:
count: 2
responsibilities:
- "Site migrations"
- "Configuration"
- "Testing"
security_engineer:
responsibilities:
- "Security policy"
- "Compliance validation"
- "Integration with SOC"
external_support:
cisco_partner:
role: "Implementation support"
engagement: "On-site during critical migrations"
cisco_tac:
role: "Technical escalation"
engagement: "As needed"
Decision Framework¶
decision_framework:
go_no_go_criteria:
pre_migration:
mandatory:
- "All prerequisites met"
- "Rollback procedure tested"
- "Stakeholder notification complete"
- "Monitoring in place"
recommended:
- "Lab validation complete"
- "Similar site migrated successfully"
during_migration:
continue_criteria:
- "No critical errors"
- "Traffic flowing normally"
- "Within maintenance window"
stop_criteria:
- "Critical application impact"
- "Unable to complete within window"
- "Unexpected errors"
post_migration:
success_criteria:
- "All validation tests pass"
- "Performance within baseline"
- "No user complaints"
- "Monitoring stable for 24 hours"
rollback_criteria:
- "Critical issues unresolved"
- "Performance significantly degraded"
- "Business-critical application failure"
7.1.6 Communication Plan¶
Stakeholder Communication¶
communication_plan:
internal_communications:
executive_updates:
audience: "CTO, IT Director, Business Leaders"
frequency: "Weekly"
format: "Executive summary email + dashboard"
content:
- "Overall progress"
- "Key milestones"
- "Risks and issues"
- "Upcoming activities"
project_team:
audience: "All project team members"
frequency: "Daily during migration"
format: "Stand-up meeting"
content:
- "Previous day accomplishments"
- "Current day plan"
- "Blockers"
it_operations:
audience: "NOC, Help Desk"
frequency: "Before each migration"
format: "Briefing + documentation"
content:
- "Migration schedule"
- "Expected impacts"
- "Escalation procedures"
end_users:
audience: "Affected site users"
frequency: "Before each migration"
format: "Email notification"
content:
- "Migration date and time"
- "Expected downtime (if any)"
- "Contact for issues"
external_communications:
vendor_coordination:
audience: "Cisco, ISP providers"
frequency: "As needed"
format: "Email, meetings"
customer_notification:
audience: "External customers (if affected)"
frequency: "Before major migrations"
format: "Formal notification"
Communication Templates¶
communication_templates:
pre_migration_notice:
subject: "SD-WAN Migration Notice - [Site Name] - [Date]"
content: |
Dear Team,
This is to inform you of a planned SD-WAN migration for [Site Name].
Date: [Date]
Time: [Start Time] - [End Time] IST
Expected Impact: [None/Minimal/Brief interruption]
What to expect:
- [Description of changes]
Action required:
- [Any user actions needed]
For any issues, contact:
- Help Desk: [Number]
- Emergency: [Number]
Regards,
IT Team
post_migration_update:
subject: "SD-WAN Migration Complete - [Site Name]"
content: |
Dear Team,
The SD-WAN migration for [Site Name] has been completed successfully.
Completion Time: [Time]
Status: [Successful/Completed with notes]
Next steps:
- [Any follow-up actions]
Please report any issues to Help Desk.
Regards,
IT Team
Document version: 1.0 Last updated: 2025 Classification: Internal Use