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
@@ -379,14 +387,32 @@ module openconfig-interfaces {
         "This leaf contains the configured, desired state of the
         interface.
 
-        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
-        has been initialized, as described in RFC 2863.
-
-        Changes in this leaf in the 'running' datastore are
-        reflected in ifAdminStatus, but if ifAdminStatus is
-        changed over SNMP, this leaf is not affected.";
+        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 has been initialized, as described in
+        RFC 2863.
+
+        Changes in this leaf in the 'running' datastore are reflected in
+        ifAdminStatus, but if ifAdminStatus is changed over SNMP, this
+        leaf is not affected.";
       reference
         "RFC 2863: The Interfaces Group MIB - ifAdminStatus";
     }
@@ -633,7 +659,16 @@ 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
@@ -653,10 +688,18 @@ module openconfig-interfaces {
       //are not used or not implemented consistently.
       mandatory true;
       description
-        "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.";
+        "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.
+
+        When the value is DOWN on an interface with a pluggable coherent
+        transceiver, the transceiver SHOULD be in low-power-mode,
+        subject to all channels sharing the transceiver being disabled.
+        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;