diff --git a/features/fedramp_extensions.feature b/features/fedramp_extensions.feature
index ad74628be..9c6bbcbd4 100644
--- a/features/fedramp_extensions.feature
+++ b/features/fedramp_extensions.feature
@@ -122,6 +122,7 @@ Examples:
   | information-type-system |
   | inter-boundary-component-has-information-type |
   | inter-boundary-component-information-type-has-class-attribute |
+  | interconnection-component-linked-has-protocol |
   | interconnection-direction |
   | interconnection-security |
   | inventory-item-allows-authenticated-scan |
@@ -390,6 +391,8 @@ Examples:
   | inter-boundary-component-has-information-type-PASS.yaml |
   | inter-boundary-component-information-type-has-class-attribute-FAIL.yaml |
   | inter-boundary-component-information-type-has-class-attribute-PASS.yaml |
+  | interconnection-component-linked-has-protocol-FAIL.yaml |
+  | interconnection-component-linked-has-protocol-PASS.yaml |
   | interconnection-direction-FAIL.yaml |
   | interconnection-direction-PASS.yaml |
   | interconnection-security-FAIL.yaml |
diff --git a/src/content/rev5/examples/ssp/xml/fedramp-ssp-example.oscal.xml b/src/content/rev5/examples/ssp/xml/fedramp-ssp-example.oscal.xml
index 5b681cd60..e0605f9db 100644
--- a/src/content/rev5/examples/ssp/xml/fedramp-ssp-example.oscal.xml
+++ b/src/content/rev5/examples/ssp/xml/fedramp-ssp-example.oscal.xml
@@ -2315,6 +2315,54 @@ approved.</p>
       </protocol>
     </component>
 
+    <component uuid="11111111-2222-4000-8000-009000200006" type="interconnection">
+       <title>Authorized Connection Information System Name</title>
+       <description>
+          <p>Describe the purpose of the external system or service.</p>
+       </description>
+       <prop name="nature-of-agreement" value="contract" ns="http://fedramp.gov/ns/oscal"/>
+       <prop name="authentication-method" value="yes" ns="http://fedramp.gov/ns/oscal">
+          <remarks>
+             <p>If 'yes', describe the authentication method in the remarks.</p>
+             <p>If 'no', explain why no authentication is used in the remarks.</p>
+             <p>If 'not-applicable', attest explain why authentication is not applicable in the remarks.</p>
+          </remarks>
+       </prop>
+       <prop name="information-type" class="incoming" value="C.3.5.1" ns="http://fedramp.gov/ns/oscal"/>
+       <prop name="information-type" class="incoming" value="C.3.5.8" ns="http://fedramp.gov/ns/oscal"/>
+       <prop name="ipv4-address" class="local" value="10.1.1.1"/>
+       <prop name="ipv6-address" class="local" value="::ffff:10.1.1.1"/>
+       <prop name="ipv4-address" class="remote" value="10.2.2.2"/>
+       <prop name="ipv6-address" class="remote" value="::ffff:10.2.2.2"/>
+       <prop name="connection-security" value="tls-1.3" ns="http://fedramp.gov/ns/oscal"/>
+       <prop name='diagram-label' ns='http://fedramp.gov/ns/oscal' value='label'/>
+       <link rel="used-by" href="#11111111-2222-4000-8000-009000100002">
+          <text>UUID of remote system</text>
+       </link>
+       <link rel="used-by" href="#11111111-2222-4000-8000-009000000000">
+          <text>UUID of remote system</text>
+       </link>
+       <link rel="used-by" href="#11111111-2222-4000-8000-009000100001">
+          <text>UUID of remote system</text>
+       </link>
+       <status state="operational"/>
+       <responsible-role role-id="provider">
+          <party-uuid>44444444-2222-4000-8000-004000000001</party-uuid>
+       </responsible-role>
+       <responsible-role role-id="isa-poc-remote">
+          <party-uuid>11111111-2222-4000-8000-004000000008</party-uuid>
+       </responsible-role>
+       <responsible-role role-id="isa-poc-local">
+          <party-uuid>11111111-2222-4000-8000-004000000008</party-uuid>
+       </responsible-role>
+       <responsible-role role-id="administrator">
+          <prop name="privilege-uuid" value="11111111-2222-4000-8000-008000000004" ns="http://fedramp.gov/ns/oscal"/>
+          <party-uuid>11111111-2222-4000-8000-004000000010</party-uuid>
+          <party-uuid>11111111-2222-4000-8000-004000000011</party-uuid>
+          <party-uuid>11111111-2222-4000-8000-004000000012</party-uuid>
+       </responsible-role>
+    </component>
+
     <!-- Appendix M - Inventory -->
     <inventory-item uuid="11111111-2222-4000-8000-011000000001">
       <description>
diff --git a/src/validations/constraints/content/ssp-interconnection-component-linked-has-protocol-INVALID.xml b/src/validations/constraints/content/ssp-interconnection-component-linked-has-protocol-INVALID.xml
new file mode 100644
index 000000000..ee440c824
--- /dev/null
+++ b/src/validations/constraints/content/ssp-interconnection-component-linked-has-protocol-INVALID.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<?xml-model href="https://github.com/usnistgov/OSCAL/releases/download/v1.1.3/oscal_ssp_schema.xsd" schematypens="http://www.w3.org/2001/XMLSchema" title="OSCAL complete schema"?>
+<system-security-plan xmlns="http://csrc.nist.gov/ns/oscal/1.0" uuid="df903c4c-6bb5-4b78-8a71-c5baa06a9f2e">
+    <system-implementation>
+        <component uuid="11111111-2222-4000-8000-009000200002" type="interconnection">
+           <link rel="used-by" href="#11111111-2222-4000-8000-009000200003">
+           </link>
+        </component>
+        <component uuid="11111111-2222-4000-8000-009000200003" type="service">
+           <!-- <protocol name="smtp">
+           </protocol> Missing protocol assembly. -->
+        </component>
+    </system-implementation>
+</system-security-plan>
\ No newline at end of file
diff --git a/src/validations/constraints/fedramp-external-constraints.xml b/src/validations/constraints/fedramp-external-constraints.xml
index 4b0a10584..ea9c91114 100644
--- a/src/validations/constraints/fedramp-external-constraints.xml
+++ b/src/validations/constraints/fedramp-external-constraints.xml
@@ -680,6 +680,18 @@
         </constraints>
     </context>
 
+    <context>
+        <metapath target="/system-security-plan/system-implementation/component"/>
+        <constraints>
+            <let var="interconnection-component-used-by-href" expression=".[@type=('interconnection', 'connection')]/link[@rel='used-by']/@href"/>
+            <expect id="interconnection-component-linked-has-protocol" target=".[@type=('interconnection', 'connection')]" test="some $href in $interconnection-component-used-by-href satisfies count(../component[@uuid=substring-after($href,'#')]/protocol) >= 1" level="ERROR">
+                <formal-name>Linked Interconnection Component Has Protocol</formal-name>
+                <prop namespace="https://docs.oasis-open.org/sarif/sarif/v2.1.0" name="help-url" value="https://automate.fedramp.gov/documentation/ssp/4-ssp-template-to-oscal-mapping/#ports-protocols-and-services"/>
+                <message>In a FedRAMP SSP, at least one of the interconnection "used-by" linked components MUST have at least one protocol assembly.</message>
+            </expect>
+        </constraints>
+    </context>
+
 
     <context>
         <metapath target="/system-security-plan/system-implementation/inventory-item"/>
diff --git a/src/validations/constraints/unit-tests/interconnection-component-linked-has-protocol-FAIL.yaml b/src/validations/constraints/unit-tests/interconnection-component-linked-has-protocol-FAIL.yaml
new file mode 100644
index 000000000..486bafceb
--- /dev/null
+++ b/src/validations/constraints/unit-tests/interconnection-component-linked-has-protocol-FAIL.yaml
@@ -0,0 +1,8 @@
+# Driver for the invalid interconnection-component-linked-has-protocol constraint unit test.
+test-case:
+  name: The invalid interconnection-component-linked-has-protocol constraint unit test.
+  description: Test that the FedRAMP SSP interconnection "used-by" linked component does not have a protocol assembly.
+  content: ../content/ssp-interconnection-component-linked-has-protocol-INVALID.xml
+  expectations:
+  - constraint-id: interconnection-component-linked-has-protocol
+    result: fail
\ No newline at end of file
diff --git a/src/validations/constraints/unit-tests/interconnection-component-linked-has-protocol-PASS.yaml b/src/validations/constraints/unit-tests/interconnection-component-linked-has-protocol-PASS.yaml
new file mode 100644
index 000000000..486e1de1a
--- /dev/null
+++ b/src/validations/constraints/unit-tests/interconnection-component-linked-has-protocol-PASS.yaml
@@ -0,0 +1,8 @@
+# Driver for the valid interconnection-component-linked-has-protocol constraint unit test.
+test-case:
+  name: The valid interconnection-component-linked-has-protocol constraint unit test.
+  description: Test that the FedRAMP SSP interconnection "used-by" linked component has a protocol assembly.
+  content: ../../../content/rev5/examples/ssp/xml/fedramp-ssp-example.oscal.xml
+  expectations:
+  - constraint-id: interconnection-component-linked-has-protocol
+    result: pass
\ No newline at end of file