MDR, MSSP, and SOC are three cybersecurity models people routinely confuse. A SOC (Security Operations Center) is your own team, processes, and monitoring technology that you build and run yourself. An MSSP outsources security-device and alert management. MDR is an outcome-focused service: it detects threats and actively responds, not just notifies.
How MDR differs from an MSSP
The core distinction is what the provider is accountable for and how their work is measured. An MSSP (Managed Security Service Provider) grew historically out of outsourced infrastructure operations: the provider runs your firewalls, IDS/IPS, antivirus, gateways, and SIEM, generates alerts, and hands them to you. Its metric is device uptime and event volume processed. Incident response usually stays on the customer's side: the MSSP says "we see suspicious activity," but investigating and stopping the attack is on you.
MDR (Managed Detection and Response) works differently. Per Gartner's definition, MDR services deliver remotely delivered modern security operations center (SOC) functions focused on rapid detection, analysis, investigation, and active response through threat mitigation and containment. The MDR metric is the outcome: mean time to detect (MTTD) and mean time to respond (MTTR), not the number of tickets closed. An MDR provider does not just forward an alert — it triages, filters false positives, and on a confirmed threat isolates the host, blocks the account, or rolls back the malicious process.
In practice the line blurs: many MSSPs added MDR offerings, and some MDR providers also take on device management. But the fundamental difference holds: an MSSP manages your tools, MDR manages your risk.
- MSSP focus: technology, devices, operations, compliance, event volume.
- MDR focus: threats, attacker behavior, response speed, damage reduction.
- Technology: an MSSP often works on top of your SIEM; MDR typically brings its own EDR/XDR-based telemetry stack.
- Response: the MSSP notifies, MDR acts — up to remote containment.
For the underlying terms, read the standalone explainers: what is MDR and what is an MSSP.
MDR vs an in-house SOC
An in-house SOC is when the organization fully builds and runs its own monitoring center: it hires analysts, buys and tunes SIEM, EDR, and orchestration (SOAR), writes playbooks, and staffs shifts around the clock. NIST's SP 800-61 and related guidance describe such a center as the backbone of the incident-handling lifecycle: detection, analysis, containment, eradication, and recovery. Full control over data and process is the in-house SOC's main advantage.
But this model carries a high cost to stand up and sustain. True 24/7 coverage needs at least five to six analyst shifts to cover every hour without burnout. On top of that come SIEM licenses (often priced by log volume), detection engineers who write and maintain rules, and a constant battle against alert fatigue. The cybersecurity skills shortage makes hiring and retaining strong analysts especially hard.
MDR removes most of that burden: the provider brings a ready-made team, battle-tested playbooks, and telemetry across many customers, which yields broader threat context. The trade-off is less control and dependency on someone else's stack and SLA. Many mature organizations land on a hybrid: they keep a small internal SOC for governance, business context, and incident ownership, and hand off overnight coverage, first-line triage, and threat hunting to an MDR provider.
The rule of thumb is simple: build your own if control, customization, and data sovereignty are critical and you have the budget for a team. Choose MDR if you need outcomes and speed without a multi-year SOC build from scratch.
What each model includes
To keep the comparison concrete, here is a typical scope of work. Exact boundaries vary by provider, but the overall picture holds.
- In-house SOC: log collection and retention, SIEM/EDR/SOAR deployment and maintenance, detection rule engineering, 24/7 monitoring, alert triage, incident investigation, full response and recovery, reporting to leadership and regulators.
- MSSP: security-device management (firewalls, IPS, gateways), baseline SIEM monitoring and correlation, alert generation and escalation, vulnerability and patch management, compliance reporting. Response is usually advisory.
- MDR: sensor deployment (EDR/XDR/NDR), continuous behavior-based monitoring and detection, expert triage and investigation, proactive threat hunting, active response (host isolation, account lockout, containment), root-cause remediation guidance.
It is important to understand that neither an MSSP nor MDR fully replaces internal risk-management functions. The business owner still defines asset criticality, approves acceptable containment actions, and is accountable for long-term recovery and post-incident lessons. Both MSSP and MDR are force multipliers, not a full delegation of responsibility.
SIEM and EDR are the technology foundation beneath all three models. If you are missing the basics, see what is SIEM: without centralized event collection, no SOC works at all.
Comparison table: SOC vs MSSP vs MDR
| Criterion | In-house SOC | MSSP | MDR |
|---|---|---|---|
| What it is | Your internal monitoring center: people, process, technology | Outsourced security-device and alert management | Managed threat detection and active response service |
| Who operates | Your team | Provider runs the tools, you own the risk | Provider owns detection and response |
| Scope | Full lifecycle: logs, SIEM/EDR, detections, 24/7 monitoring, response | Devices, baseline correlation, alert escalation, compliance | EDR/XDR telemetry, behavioral detection, threat hunting, triage |
| Response | Full, in-house | Notification (advisory) | Active: isolation, lockout, containment |
| Cost model | CAPEX + ongoing OPEX (salaries, SIEM licenses) | Per device / log volume / source | Subscription per endpoint / user / asset |
| Best for | Large, regulated organizations with budget and control needs | Those needing device operations and compliance | SMBs and anyone prioritizing speed and outcomes |
Cost and SLA
The models differ not only in scope but in how price is formed and which commitments the SLA locks in.
An in-house SOC is mostly capital and ongoing operating expense: analyst and engineer salaries, SIEM licensing (often by data volume — gigabytes or events per second), storage infrastructure, and staff training and retention. The SLA here is internal: you set your own MTTD/MTTR targets and answer for them yourself. The upside is predictability and control; the downside is a high cost base that grows with scale.
An MSSP is usually priced by the number of managed devices, log volume, or number of sources. Its SLA more often covers service availability and time to react to an alert (for example, escalation within N minutes), but not the actual stopping of an attack. Accountability for the incident outcome stays fuzzy.
MDR is most commonly priced per endpoint, per user, or by the volume of protected assets, on a subscription. The key difference is that the SLA is tied to an outcome: the provider commits to time to detect and — more importantly — time to respond and contain. The presence of active-response commitments in the SLA is the practical way to tell genuine MDR from "an MSSP with good marketing."
Do not compare offers on the sticker price alone. A seemingly identical quote can hide a fundamentally different scope: is threat hunting included, who pays for investigation, is there a monthly incident cap, does the price cover active containment or only notification? Always request a written RACI matrix and concrete SLA metrics.
How to choose by company size
There is no single right answer — the choice depends on maturity, regulation, budget, and risk tolerance. But there are workable guideposts by scale.
- Small business (up to ~100 employees). Building your own SOC is almost never economical. MDR is usually optimal: fast start, active response, and expertise without hiring a team. An MSSP fits if your main pain is device management and basic compliance rather than advanced detection.
- Mid-market (~100–1000 employees). A hybrid usually wins: MDR for 24/7 detection and response plus, possibly, an MSSP for infrastructure operations. A small internal security group manages the providers and owns business context.
- Large enterprise (1000+ employees, regulated industries). An in-house SOC is often justified for control, custom detections, and data sovereignty, frequently augmented by MDR for overnight shifts, surge capacity, and specialized threat hunting.
A practical decision algorithm:
- Assess maturity: do you have the people, processes, and technology for 24/7 monitoring? If not, do not try to build a SOC "for future growth."
- Identify the main gap: not enough hands to operate tools (→ MSSP) or not enough expertise to detect and respond to real attacks (→ MDR)?
- Check regulatory requirements for data localization and ownership — they may dictate an in-house or local SOC.
- Calculate total cost of ownership (TCO), not just the sticker price: people, licenses, training, downtime during an incident.
- Demand an SLA with response and containment metrics, not availability alone.
To assess your current perimeter objectively before talking to providers, start with a basic attack-surface self-check: verify your security headers, TLS certificates, open ports, and DNS yourself — that gives you the facts for a concrete conversation about whether you need MDR, an MSSP, or a SOC.
FAQ
Does MDR replace a SIEM?
No. A SIEM is a platform for collecting and correlating events, while MDR is a service on top of telemetry. Many MDR providers bring their own EDR/XDR-based stack and may not require your SIEM, but the centralized-logging function does not disappear — it is built into the service.
Can an MSSP perform response?
Some MSSPs have expanded into response, but classically an MSSP notifies you of an incident while the customer investigates and stops the attack. If a provider promises active containment with an MTTR SLA, that is effectively an MDR function as Gartner defines it.
Do I still need my own SOC if I have MDR?
Not necessarily. For small and mid-sized businesses, MDR often covers the need entirely. Large organizations benefit from a hybrid: an internal SOC for governance and context plus MDR for 24/7 coverage and threat hunting.
Which is cheaper — MDR or an in-house SOC?
For most companies below large scale, MDR is cheaper on total cost of ownership: you avoid hiring five to six analyst shifts and carrying SIEM licenses. An in-house SOC starts to pay off at large volumes and under strict control and data-localization requirements.
How does MDR differ from EDR?
EDR (Endpoint Detection and Response) is an endpoint technology; MDR is a managed service that uses EDR (and other telemetry) together with human analysts. Buying EDR without a team means having a tool with no operators. See the explainer on what is EDR.
Where should I start the selection?
With an honest assessment of maturity and your main gap. If you lack detection expertise and response speed, look at MDR. If you need device operations and compliance, an MSSP. If control and data sovereignty are critical and you have the budget, build a SOC, augmenting it with MDR where needed.