Case Study · Infrastructure & Observability

Replacing a licensed enterprise
monitoring stack — 80% cost reduction.

A large enterprise was spending heavily on vendor licensing across HP, Cisco, Splunk, SolarWinds, and others for critical network monitoring. We replaced the entire stack with open source and best-of-breed alternatives — preserving every capability, improving performance, and cutting costs by 80%.

IndustryEnterprise IT / Network Operations
EngagementTechnology Consulting & Delivery
ClientConfidential
80%
Cost reduction

Licensing, support contracts, and per-seat fees eliminated

10+
Tools replaced

Every proprietary tool mapped to a capable open source alternative

0
Functionality lost

Full feature parity achieved across all monitoring domains

↑
Performance gained

Leaner stack, purpose-configured, with better resolution metrics

The Challenge

Mission-critical monitoring. Unsustainable cost.

The client operated a large, distributed enterprise network — thousands of devices across multiple sites, running 24/7. The monitoring stack that kept it visible had been assembled over years from best-of-breed vendors: Cisco for discovery and configuration, HP for fault management, Splunk for log aggregation and SIEM, SolarWinds for performance metrics, and PagerDuty for alerting.

Each tool worked. But together they represented an enormous, growing licensing burden. Splunk alone — charged per GB of daily log ingestion — had become the single largest line item in the IT budget. Cisco DNA Center and HP NNM carried per-device fees that scaled with the network. AppDynamics billed per CPU. PagerDuty charged per user.

The ask was direct: eliminate the cost without eliminating the capability. Every alert, every dashboard, every topology view, every security feed had to continue functioning. The operations team could not miss a beat.

What was at stake
  • 24/7 fault detection across thousands of devices
  • Real-time security monitoring and intrusion detection
  • Log aggregation from network, server, and application layers
  • NetFlow traffic analysis and bandwidth trending
  • Configuration versioning and change alerts
  • On-call alerting with escalation and scheduling
Primary cost drivers
  • Splunk per-GB ingestion at enterprise scale
  • Cisco per-device licensing across all tools
  • HP enterprise node-tier contracts
  • SolarWinds per-element annual renewals
  • PagerDuty per-user SaaS subscriptions
  • Vendor support contracts on top of each
Architecture

Before & after the migration

BeforeProprietary stack · High licensing cost
Enterprise Network
Routers · Switches · Firewalls · Servers · Applications
↓
Collection
Cisco PrimeHP NNMSolarWinds NPMCisco NetFlow
Log & Security
Splunk EnterpriseHP ArcSightCisco Stealthwatch
Management
Cisco DNA CenterHP Network AutomationAppDynamics
Alerting
PagerDutyVendor Dashboards
↓
Siloed dashboards · Vendor portals
No unified view · Context switching between tools
AfterOpen source stack · 80% lower cost
Enterprise Network
Routers · Switches · Firewalls · Servers · Applications
↓
Collection
LibreNMSPrometheus + Exportersntopng / nfdumpZabbix
Log & Security
Logstash → ElasticsearchSuricata + ZeekWazuh SIEM
Management
NetBox (CMDB)Oxidized (Config)Jaeger (Tracing)
Visualise & Alert
GrafanaKibanaAlertmanager + OnCall
↓
Grafana · Unified observability plane
Single pane of glass across all layers
Tool Migration Map

Every tool. Every replacement. No gaps.

Each proprietary tool was audited against its actual usage. A capable open source alternative was selected, validated, and configured to match or exceed the original functionality before the licensed tool was decommissioned.

Monitoring DomainProprietary ToolCost DriverOSS ReplacementOutcome
Network Discovery & TopologyCisco Prime InfrastructurePer-device licensing + support contractsLibreNMSAuto-discovery, topology maps, SNMP polling — all retained
Fault ManagementHP Network Node Manager (NNM)Enterprise node-based license tiersZabbixRicher alerting with custom thresholds and escalation policies
Log Management & SIEMSplunk EnterprisePer-GB daily ingestion — the largest single cost itemELK Stack (Elasticsearch · Logstash · Kibana)Unlimited log ingestion, full-text search, custom dashboards
Performance MonitoringSolarWinds NPMPer-element license with annual renewalPrometheus + GrafanaHigher resolution metrics, flexible retention, superior visualisation
Traffic & Flow AnalysisCisco NetFlow AnalyzerPer-interface / per-flow licensingntopng + nfdumpReal-time flow analysis, bandwidth trending, top-talker reports
Network Config ManagementHP Network AutomationEnterprise license with device count capsOxidized + RancidGit-backed config versioning for every device, diff alerts on change
CMDB & Asset InventoryCisco DNA CenterSaaS subscription + per-seat access costsNetBoxFull IPAM, rack management, asset tracking — self-hosted and customised
Security & Intrusion DetectionCisco Stealthwatch + HP ArcSightPer-flow and per-agent licensingSuricata + Zeek + WazuhDeep packet inspection, threat hunting, SIEM — integrated into the same stack
Alert Routing & On-CallPagerDutyPer-user monthly subscriptionPrometheus Alertmanager + Grafana OnCallSame escalation policies, schedules, and integrations — no per-seat cost
APM & TracingAppDynamicsPer-agent CPU-based licensingPrometheus + Jaeger + OpenTelemetryDistributed tracing, service maps, latency breakdown fully retained
Our Approach

Methodical migration. Zero downtime.

01

Full stack audit

We began with a complete inventory of every licensed tool in use — its function, the data it processed, the dashboards and alerts it powered, and its actual cost. Each tool was assessed against real usage patterns, not theoretical capability. Several tools were underused; some were redundant.

02

Tool-by-tool mapping

For every proprietary tool, we identified and documented the best-fit open source alternative. This was not a generic recommendation — each replacement was evaluated against the client's specific environment, data volumes, alert rules, and team workflows. The full mapping was documented in a structured migration matrix.

03

Parallel deployment

New tools were deployed alongside existing ones. For a defined validation period, both stacks ran simultaneously. Alerts, dashboards, and data were compared side-by-side. Only once the open source stack demonstrated full parity — on every metric, every alert, every dataset — was the licensed tool decommissioned.

04

Custom configuration

Off-the-shelf open source tools rarely match an enterprise environment out of the box. We built custom dashboards, alert rules, integrations, and retention policies specific to this client's network topology and operational workflows. The result was a more tailored stack than the vendor tools it replaced.

05

Team handover

The operations team needed to own the new stack. We ran knowledge transfer sessions, documented the architecture, and built runbooks for common operational tasks. The team was proficient before we stepped back — not dependent on us to keep things running.

Technologies Deployed

The open source stack

LibreNMS
Network discovery, topology, SNMP polling
Zabbix
Fault management, threshold alerting
Prometheus
Metrics collection, time-series storage
Grafana
Unified dashboards, visualisation layer
Elasticsearch
Log indexing and full-text search
Logstash
Log ingestion, parsing, and enrichment
Kibana
Log exploration and SIEM dashboards
Wazuh
SIEM, threat detection, compliance monitoring
Suricata
Network intrusion detection (IDS/IPS)
Zeek
Network traffic analysis and forensics
ntopng
NetFlow analysis, bandwidth trending
NetBox
CMDB, IPAM, rack and asset inventory
Oxidized
Network config backup, Git versioning
Alertmanager
Alert routing, deduplication, escalation
Jaeger
Distributed tracing, service maps
OpenTelemetry
Telemetry instrumentation standard
Work with us

Paying too much for your monitoring stack?

If vendor licensing is eating your IT budget, we can audit your stack, map the alternatives, and manage the migration — without operational disruption.