RE: [16NG] Comments on IPv4CS subnet model and ARP

7.  Address Resolution Protocol

The IEEE 802.16 frame header does not contain the source and
destination MAC addresses, instead it uses the Connection Identifier
(CID) for the delivery of MAC frames.  This makes classical Address
Resolution Protocol (ARP) [3] trivial and unnecessary. > Also, IEEE
802.16 IPCS cannot classify the ARP packets as ARP runs directly over
 Ethernet and does not contain IP header.  Thus ARP packets are not
transmitted over IEEE 802.16 air interface when using IPCS.

Proposed Changes: The IEEE 802.16 frame header does not contain the
source and destination MAC addresses, instead it uses the Connection
Identifier (CID) for the delivery of MAC frames.  This makes classical
Address Resolution Protocol (ARP) [3] trivial and unnecessary. Also,
IEEE 802.16 IPCS cannot classify the ARP packets as ARP runs directly
over Ethernet and does not contain IP header. Thus ARP packets are not
  transmitted over IEEE 802.16 air interface when using IPCS. However
MS requires to proxy ARP function compatible with legacy IP host.

[SC>] Let's discuss the last sentence. MS requires to proxy ARP function compatible with legacy IP host: What is the expected configuration of the scenario in this case? The legacy IP host will not be on the same Wimax IPCS
link; thus our assumption was that they would be on different subnets.
Please clarify.

[sekim] For example, legacy IP host is a notebook PC with IEEE802.16 wireless interface on Window by Microsoft.
IP hosts send a packet to the Base Station (BS) by unicast. Because IEEE 802.16 does not support broadcast among the nodes.
The uplink, from node to BS, supports unicast.
The downlink, from BS to node, supports multicast and broadcast.
Therefore, [RFC1207] should be used to support ARP capabilities for point to multipoint mode in IEEE 802.16 networks.
 If not, legacy host should use broadcast like IEEE 802.3. This means multicast and broadcast scheme are required in IEEE802.16 networks.