SC-47: Alternate Communications Paths

The sc-47: alternate communications paths requirement is about keeping command-and-control communications working during the exact conditions that break normal channels: network outages, degraded routing, denial-of-service, cloud service disruption, compromised email, or an incident that forces you to isolate parts of the environment. SC-47 sits in the System and Communications Protection (SC) family and focuses specifically on communications paths used for operational direction, escalation, and coordination.

For a Compliance Officer, CCO, or GRC lead, SC-47 becomes actionable when you translate “alternate communications paths” into a small set of concrete, pre-approved options that your operations and incident response teams will actually use. That means: (1) identify which communications are truly “command and control” for system operations, (2) ensure at least one alternate path is meaningfully independent from the primary path, (3) train staff and run tests, and (4) retain evidence that proves the capability exists and works.

This page gives you requirement-level implementation guidance: scope, ownership, step-by-step actions, artifacts to retain, and common audit pitfalls, based on the control statement in NIST SP 800-53 Rev. 5. ¹

Regulatory text

Control statement (excerpt): “Establish {{ insert: param, sc-47_odp }} for system operations organizational command and control.” ²

What the operator must do

You must establish alternate communications paths that support system operations command-and-control. Practically, an assessor will expect you to show:

• You identified which communications are required to run and recover systems (command-and-control).
• You implemented at least one alternate path that can be used if normal channels are unavailable or untrusted.
• You can switch to the alternate path under defined conditions.
• The alternate path is maintained (accounts, devices, contact lists, permissions) and tested.

Because the control text uses an organization-defined parameter (“{{ insert: param, sc-47_odp }}”), you must write down your definition of “alternate communications paths” and the scope of “system operations organizational command and control” in your environment. That definition becomes the standard you are audited against. ²

Plain-English interpretation

SC-47 means: if the normal way your teams coordinate operations is down or compromised, you still have a reliable way to direct actions. This is not about end-user business communications; it targets the communications that run the system: on-call paging, incident bridges, war-room chat, escalation to cloud admins, direction to isolate networks, emergency changes, and crisis approvals.

A clean way to interpret “alternate” for audit and operations:

• Alternate = usable under different failure modes than the primary path (power, ISP, identity provider, email domain, collaboration suite, enterprise network).
• Alternate = pre-provisioned and authorized (no scrambling to create accounts mid-incident).
• Alternate = known, documented, and practiced.

Who it applies to

Entity scope

• Federal information systems and organizations implementing NIST SP 800-53 controls. ³
• Contractor systems handling federal data, where NIST SP 800-53 controls are flowed down via contract, ATO boundary requirements, or agency security requirements. ³

Operational context (what to include)

Include communications used by:

• NOC/SOC operations (incident triage, containment direction, status reporting).
• SRE / platform operations (outage mitigation, rollback direction, emergency access workflows).
• IT operations (identity, network, endpoint, telecom, email administration).
• Crisis management where it directly directs technical response (executive comms belong here only if they gate technical actions).

Exclude or de-prioritize:

• General employee communications that do not direct system operations (unless your environment relies on them for operational command-and-control).

What you actually need to do (step-by-step)

Step 1: Define “command-and-control communications” for your environment

Document the minimum set of communications required to:

• Declare an incident/outage
• Mobilize responders
• Assign tasks and track completion
• Approve emergency changes
• Communicate “disconnect/isolate/shutdown” decisions

Output: a short SC-47 scope statement and a communication dependency map (primary channels and what they depend on).

Step 2: Identify realistic failure and compromise modes

Run a quick tabletop with IT/SecOps and list plausible conditions that would break or poison primary comms:

• Collaboration suite outage
• Email compromise or domain lockout
• Corporate VPN failure
• Identity provider outage blocking access to chat/bridge tools
• Network segmentation during containment

Output: SC-47 failure-mode list with “primary channel impact” and “alternate channel used.”

Step 3: Design alternate paths that are meaningfully independent

Independence is the make-or-break point in audits. If your “alternate” depends on the same identity system, same network, or same vendor, it may fail the same way.

Common patterns that assess well:

• Out-of-band conferencing: a bridge line hosted outside your primary collaboration stack.
• Out-of-band paging/SMS: separate provider or pre-configured on-call escalation not tied to corporate SSO.
• Secondary secure messaging: a separately administered channel with break-glass access (and clear rules for use).
• Radio/satellite for specific high-availability or critical infrastructure contexts (only if relevant to your ops model).

Output: an Alternate Communications Paths Design (one page) listing each path, owner, dependencies, and activation trigger.

Step 4: Establish governance and operating procedure

Write an SC-47 procedure that answers, in plain language:

• Who can declare “primary comms degraded/untrusted”
• How to activate the alternate path (exact steps)
• Where the current contact roster lives and how it’s updated
• How to handle authentication if SSO is down (break-glass accounts, pre-shared codes, or offline token processes)
• Which communications are allowed over the alternate path (avoid spilling sensitive data into insecure channels)

Tie the procedure to your incident response process so teams use it under stress, not only for audits.

Step 5: Provision, secure, and maintain the alternate path

Minimum operational controls that prevent the alternate path from becoming shelfware:

• Pre-provision accounts, roles, and licenses (if needed)
• Store critical access details in a controlled, accessible location during outages
• Assign an owner for roster hygiene (on-call rotations change constantly)
• Confirm the alternate path works from outside corporate networks (home network, mobile)

Step 6: Test and exercise

Run exercises that prove the path works under realistic constraints:

• Primary chat/email assumed unavailable
• Participants required to join via alternate method
• A short “command-and-control” script: declare incident, assign tasks, confirm acknowledgments, share status cadence

Record results, issues, and remediation actions. This is often the most persuasive evidence for assessors because it shows operational readiness, not just design intent.

Step 7: Map ownership, procedures, and recurring evidence (audit readiness)

SC-47 is frequently failed on evidence, not engineering. Create a control record that maps:

• Control owner (role and name)
• In-scope systems/teams
• Procedure references
• Evidence list and collection frequency

Daydream (or any GRC system you already run) fits here as the system of record to track control ownership, link procedures, and collect recurring artifacts without relying on heroics before an assessment.

Required evidence and artifacts to retain

Keep artifacts that prove design, implementation, and operation:

1. SC-47 control narrative (how alternate paths are established; what “alternate” means in your org).
2. Communications dependency map (primary vs. alternate, dependencies such as SSO, ISP, corporate network).
3. Procedure / runbook for comms failover (activation triggers, steps, roles).
4. Access management evidence for the alternate path (admin list, break-glass approach, approvals).
5. Contact roster and maintenance records (who updates it, evidence of updates).
6. Test/exercise records (tabletop notes, screenshots, bridge attendance logs, after-action reports, tickets showing fixes).
7. Training/awareness evidence for responders (short job aid, onboarding checklist for on-call staff).

Common exam/audit questions and hangups

Assessors and auditors tend to press on:

• “What’s the alternate path, exactly?” Vague answers fail. Name the tool/provider and show the runbook.
• “Is it independent?” If both primary and alternate require the same SSO tenant, the same corporate VPN, or the same SaaS vendor, explain why that still meets your failure-mode assumptions or add another path.
• “How do you know it works?” Show an exercise record with an assumption that primary comms are down.
• “Who owns it?” “The SOC” is not ownership. Assign a role accountable for operability and evidence.
• “What triggers failover?” You need defined triggers (unavailable, degraded, untrusted/compromised).

Frequent implementation mistakes (and how to avoid them)

1. Alternate path shares the same dependency chain.
   Fix: document dependencies and choose at least one out-of-band option that bypasses your most likely single points of failure.

2. No break-glass access plan.
   Fix: define how responders authenticate when SSO is unavailable or suspected compromised, and practice it.

3. Contact lists rot.
   Fix: make roster updates part of on-call rotation changes and attach it to a change/ticket workflow.

4. Runbook exists but nobody follows it.
   Fix: embed the comms-failover step into incident templates and run a drill that forces its use.

5. Evidence is scattered.
   Fix: centralize artifacts in your GRC record (Daydream or equivalent): owner, links, and a recurring evidence checklist.

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this requirement, so this page does not list enforcement examples.

Operational risk still matters: if you cannot coordinate response during a communications outage or compromise, containment and recovery slow down, decision-making fragments, and you are more likely to take inconsistent actions (for example, partial isolation that preserves attacker access). SC-47 reduces that operational fragility by pre-establishing a viable command-and-control channel. ³

Practical execution plan (30/60/90)

You can execute SC-47 quickly if you timebox decisions and focus on evidence.

First 30 days (establish and document)

• Name a control owner and backups.
• Write your SC-47 scope statement (what counts as command-and-control).
• Identify primary comms and their dependencies.
• Choose at least one alternate path and document why it remains viable under your top failure modes.
• Draft the comms failover runbook and a one-page responder job aid.

By 60 days (implement and operationalize)

• Provision accounts, roles, and break-glass access for the alternate path.
• Publish and train: on-call teams, incident commanders, IT admins.
• Integrate SC-47 into incident response templates (declare, mobilize, alternate comms step).
• Start evidence collection in your GRC system: narrative, runbook, roster, access list.

By 90 days (prove it works and keep it alive)

• Run at least one exercise that forces alternate path usage and produces an after-action record.
• Fix issues found in the exercise (tickets + closure evidence).
• Establish a recurring maintenance routine: roster updates, access reviews, and periodic comms tests.
• Confirm artifact completeness for assessment: a single SC-47 record with linked evidence.

Frequently Asked Questions

What counts as an “alternate communications path” for SC-47?

It’s a pre-established way to coordinate system operations command-and-control when the normal channel is unavailable or untrusted. The key test is whether it remains usable under the failure modes that break your primary channel. ²

Does SC-47 require multiple alternate paths?

The control text requires you to “establish” alternate communications paths, but it leaves the organization-defined details to you. In practice, pick an alternate that covers your highest-risk failure modes and document your rationale. ²

If our primary comms is Microsoft Teams/Slack, can our alternate be another channel in the same tool?

That rarely meets the intent because the same outage, identity issue, or tenant compromise can affect both. If you keep it, document the dependency analysis and add an out-of-band option for the failure modes that would take the platform down.

How do we handle authentication if SSO is down or suspected compromised?

Define a break-glass approach that does not depend on the same failing control plane, and restrict it tightly (limited admins, logging, approvals where feasible). Then test it in an exercise so you know it works under pressure.

What evidence do auditors accept for SC-47?

Auditors typically want a runbook, proof the alternate path exists (accounts/configuration), a maintained contact roster, and at least one exercise record showing the path was used successfully. Keep it all mapped to an owner and a recurring evidence plan.

How should we scope SC-47 in a multi-cloud or hybrid environment?

Scope by operational command-and-control functions, not by cloud. If the same incident management process covers AWS, Azure, and on-prem, your alternate paths can be shared, but document how responders reach each environment during an outage.

Footnotes

1. NIST SP 800-53 Rev. 5; NIST SP 800-53 Rev. 5 OSCAL JSON

2. NIST SP 800-53 Rev. 5 OSCAL JSON

3. NIST SP 800-53 Rev. 5