Teams Direct Routing and Contact Center as a Service (CCaaS) are often presented as competing "cloud voice" choices. They're not the same kind of thing — Direct Routing is PSTN connectivity for your users, while CCaaS is a contact center platform for your agents. But the way you combine them determines whether your voice estate is one clean system or two parallel stacks that leak money.
This comparison is for enterprises deciding how to serve both everyday users and contact-center agents on Microsoft Teams.
What Each One Actually Is
Teams Direct Routing connects your own certified SBC to Teams Phone, giving all your users PSTN calling through the carrier of your choice. Every user — including agents — can have full inbound and outbound calling. Effective trunking cost is typically $0.50–$1.50 per user per month, on top of the Teams Phone Standard license.
CCaaS (Genesys Cloud, NICE CXone, Five9, Talkdesk, and others) is an outsourced contact center: queueing, IVR, routing, workforce engagement management, quality management, and omnichannel — priced per agent, typically $50–$150+ per agent per month, sometimes with per-minute usage on top.
Architecture Option 1: Teams + Direct Routing, CCaaS as a Connector
The modern pattern: Direct Routing carries all PSTN for the tenant, and your CCaaS platform integrates natively into Teams as a certified contact center solution. Agents live in Teams; the CCaaS connector brings queueing, routing, and supervisor tooling into the Teams client. One phone number inventory, one telephony stack, one place where calls enter.
- Pros — single number management, single admin plane, no double trunking, agents keep one client, internal and external calls stay on-net
- Cons — contact center features limited to what the Teams-connector edition of your CCaaS supports; deep omnichannel AI features often lag the standalone product
Architecture Option 2: Parallel Stacks
The legacy pattern: CCaaS handles the contact center with its own numbers and its own SIP/PSTN, while Teams (with Direct Routing or even Calling Plans) handles everyone else. This is where the hidden costs live:
- Two number inventories — numbers split across two providers, two porting processes, two reconciliation cycles
- Two admin and operations planes — moves/adds/changes in two systems, two monitoring stacks, two vendors to blame during an outage
- Transfer leakage — a contact-center agent transferring to a back-office expert crosses carriers, adding per-minute cost and quality risk
- Duplicate spend — you pay CCaaS per-agent prices for agents who also sit on a per-user Teams voice stack
The Cost Math
For a 3,000-user enterprise with a 100-agent contact center:
- Option 1 — Direct Routing trunking for everyone: roughly $1,500–$4,500/month; CCaaS Teams-connector licensing for 100 agents
- Option 2 — Direct Routing for 2,900 users plus a standalone CCaaS stack with its own trunking, numbers, and per-minute usage for 100 agents
The difference is rarely dramatic at the contact center itself — agent licenses dominate either way. The difference is in the periphery: number management, transfer paths, fault domains, and the operational cost of running two stacks. That's where Option 2 quietly loses.
When CCaaS-First Wins
- Your contact center is the business (e-commerce, support-heavy) and omnichannel — chat, email, social — is core, not an add-on
- You need mature workforce engagement management and quality management out of the box
- You rely on the CCaaS vendor's AI self-service and IVR capabilities as primary infrastructure
When Teams + Direct Routing Wins
- The overwhelming majority of your users are internal, not agents
- Your "contact center" is a small group with basic queueing needs
- Your workforce lives in Microsoft 365 and you want voice inside the same client
- You want a single carrier relationship and a single SBC as the PSTN gate for everything
The Practical Recommendation
For most enterprises on Microsoft 365, the clean architecture is: Direct Routing for all users, with a Teams-certified CCaaS connector for the contact center — one SBC, one carrier, one number inventory. Choose standalone CCaaS only when omnichannel and contact-center AI are genuinely your core business.
Either way, the SBC layer and carrier strategy should be decided once, for the whole tenant. Talk to us about the architecture, or start with the certified SBC list and our ROI calculator.