Clarify enabled/admin-status descriptions for coherent transceiver low-power-mode

release/models/interfaces/openconfig-interfaces.yang

@@ -51,7 +51,15 @@ module openconfig-interfaces {
     Section 4.c of the IETF Trust's Legal Provisions Relating
     to IETF Documents (http://trustee.ietf.org/license-info).";
 
-  oc-ext:openconfig-version "3.8.1";
+  oc-ext:openconfig-version "3.9.0";
+
+  revision "2026-04-23" {
+      description
+        "Clarify enabled and admin-status descriptions for
+        coherent transceiver low-power-mode behavior.";
+      reference
+        "3.9.0";
+  }
 
   revision "2026-01-06" {
       description
@@ -379,6 +387,25 @@ module openconfig-interfaces {
         "This leaf contains the configured, desired state of the
         interface.
 
+        When set to true, the interface is enabled and operational
+        traffic is permitted.
+
+        When set to false, the interface is administratively disabled.
+        For interfaces with a pluggable coherent transceiver (e.g.
+        ZR/ZR+ optics), setting this leaf to false SHOULD additionally
+        cause the transceiver module to be placed into low-power-mode,
+        conserving power and reducing thermal load when the interface
+        is not in use.  When a coherent transceiver is shared by
+        multiple channelized interfaces, the transceiver SHOULD only
+        enter low-power-mode after every channel sharing the module
+        has this leaf set to false.  This low-power-mode behavior
+        applies only to coherent optics; for interfaces using gray
+        (direct-detect) optics or non-pluggable interfaces (e.g.
+        fixed copper ports), setting this leaf to false disables the
+        interface without any optics-specific side effects, even when
+        the underlying module would otherwise support a low-power
+        mode.
+
         Systems that implement the IF-MIB use the value of this
         leaf in the 'running' datastore to set
         IF-MIB.ifAdminStatus to 'up' or 'down' after an ifEntry
@@ -633,7 +660,16 @@ module openconfig-interfaces {
         }
         enum DOWN {
           description
-            "Not ready to pass packets and not in some test mode.";
+            "Not ready to pass packets and not in some test mode.
+
+            For interfaces with a pluggable coherent transceiver
+            (e.g. ZR/ZR+ optics), the DOWN state indicates that the
+            transceiver module SHOULD also be in low-power-mode as a
+            result of the interface being administratively disabled
+            via the enabled configuration leaf, subject to all
+            channels sharing the transceiver being disabled.  This
+            does not apply to gray (direct-detect) optics or
+            non-pluggable interfaces.";
         }
         enum TESTING {
           description
@@ -656,7 +692,14 @@ module openconfig-interfaces {
         "The desired state of the interface.  In RFC 7223 this leaf
         has the same read semantics as ifAdminStatus.  Here, it
         reflects the administrative state as set by enabling or
-        disabling the interface.";
+        disabling the interface.
+
+        When the value is DOWN on an interface with a pluggable
+        coherent transceiver, the transceiver SHOULD be in
+        low-power-mode.  This behavior does not apply to gray
+        (direct-detect) optics or non-pluggable interfaces.  See
+        the description of the enabled leaf in the interface
+        configuration for details.";
       reference
         "RFC 2863: The Interfaces Group MIB - ifAdminStatus";
       oc-ext:telemetry-on-change;