dSIPRouter Friday: Real-World Deployment — How a Detroit MSP Cut VoIP Costs by 60%

Welcome to dSIPRouter Friday — your end-of-week dose of real-world success stories and deployment insights!

This week, we're sharing how a managed service provider in Detroit transformed their clients' voice infrastructure using dSIPRouter — and slashed costs in the process.

The Challenge

Metro Tech Solutions, a Detroit-based MSP serving 45 small businesses, faced a common problem:

• Clients were locked into expensive hosted PBX contracts
• Each client had separate SIP trunks with different providers
• No centralized management or visibility
• Average client spending: $800/month on voice services

Sound familiar?

The Solution: Centralized SIP Routing

Metro Tech deployed a single dSIPRouter instance to serve all 45 clients:

Architecture Overview

┌─────────────────────────────────────────────────────┐
│                   dSIPRouter                        │
│         (Centralized SIP Proxy/SBC)                │
├─────────────────────────────────────────────────────┤
│  ┌─────────┐  ┌─────────┐  ┌─────────┐            │
│  │Client A │  │Client B │  │Client C │  ... x45   │
│  │FreePBX  │  │FusionPBX│  │ 3CX     │            │
│  └────┬────┘  └────┬────┘  └────┬────┘            │
│       └───────────┼───────────┘                    │
│                   ▼                                 │
│         ┌─────────────────┐                        │
│         │  Carrier Pool   │                        │
│         │ • Telnyx (Primary)                       │
│         │ • Twilio (Backup)                        │
│         │ • Local ILEC    │                        │
│         └─────────────────┘                        │
└─────────────────────────────────────────────────────┘

Key Configuration Decisions

1. Domain-Based Routing
Each client gets their own domain in dSIPRouter:
- clienta.metrotech.voip
- clientb.metrotech.voip

This keeps traffic isolated while sharing infrastructure.

2. Least-Cost Routing
dSIPRouter routes calls to the cheapest available carrier:
- Local calls → Regional ILEC (lowest rates)
- Long distance → Telnyx (best LD rates)
- International → Twilio (broadest coverage)

3. Automatic Failover
If Telnyx goes down, calls automatically route to Twilio — clients never notice.

The Results

After 6 months of operation:

Cost Breakdown

Before (per client):
- Hosted PBX: $400/month
- SIP trunk: $200/month
- Support overhead: $200/month
- Total: $800/month

After (per client):
- Self-hosted PBX: $50/month (VPS)
- Pooled SIP (via dSIPRouter): $150/month
- Reduced support: $120/month
- Total: $320/month

Lessons Learned

What Worked Well

✅ Pooled DID Management — Buying DIDs in bulk through one account dramatically reduced per-number costs.

✅ Centralized CDR — One dashboard for all client call records made troubleshooting 10x faster.

✅ TLS Everywhere — Encrypting all SIP traffic eliminated the VoIP fraud attempts they'd been battling.

What They'd Do Differently

⚠️ Start with monitoring — They wished they'd set up Prometheus/Grafana from day one instead of retrofitting it later.

⚠️ Document everything — As the deployment grew, tribal knowledge became a liability. Now they maintain runbooks for every procedure.

Try It Yourself

Want to replicate this setup? Here's how to get started:

1. Deploy dSIPRouter: Installation Guide
2. Configure multi-tenant routing: Domain Routing Docs
3. Set up carrier failover: Carrier Groups Tutorial

Free Consultation

Thinking about a similar deployment? The dSIPRouter team offers free architecture consultations for MSPs. Schedule a call.

Your Story?

Have a dSIPRouter success story to share? We'd love to feature it! Reach out on GitHub Discussions or email the team.

Have a great weekend! 🎉

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