Agree on semantics and name for l2-mtu

[rgwilton]

WG Last Call: draft-ietf-netmod-intf-ext-yang-07: Vladimir issue 17.

17. I have separately posted my arguments against introduction of leaf named l2-mtu and the need of a config false leaf that has similar semantics as the ifMtu object from IF-MIB.

[rgwilton]

Changed to max-frame-size (the name in IEEE 802.3)

[rgwilton]

Current proposed text:

2.5. Maximum frame size

A maximum frame size configuration leaf (max-frame-size) is provided
to specify the maximum size of a layer 2 frame that may be
transmitted or received on an interface. The value includes the
overhead of any layer 2 header, the maximum length of the payload,
and any frame check sequence (FCS) bytes. If configured, the max-
frame-size leaf on an interface also restricts the max-frame-size of
any child sub-interfaces, and the available MTU for protocols.

AND

   /*
    * Allows the maximum frame size to be configured or reported.
    */
   leaf max-frame-size {
     if-feature "max-frame-size";
     type uint32 {
       range "64 .. max";
     }
     description
       "The maximum size of layer 2 frames that may be transmitted
        or received on the interface (including any frame header,
        maximum frame payload size, and frame checksum sequence).

        If configured, the max-frame-size also limits the maximum
        frame size of any child sub-interfaces.  The MTU available
        to higher layer protocols is restricted to the maximum frame
        payload size, and MAY be further restricted by explicit
        layer 3 or protocol specific MTU configuration.";

     reference "RFC XXX, Section 2.5 Maximum Frame Size";
   }

[samans]

Text has been added previously... need to check one more time.