IEEE 802.1 wishes to acknowledge the work done by TIA TR-41.4 in its ANSI-TIA-1057 LLDP-MED specification, and draw the attention of TR-41.4 to an Interpretation and to two Draft Standards in progress in IEEE 802.1 that we feel are related to LLDP-MED: IEEE 802.1 Interpretation #4 (http://www.ieee802.org/1/pages/int-4.html) IEEE Project P802.1AB-REV - Station and Media Access Control Connectivity Discovery Revision (http://www.ieee802.org/1/pages/802.1AB-rev.html) IEEE Project P802.1aj Two-Port MAC Relay (http://www.ieee802.org/1/pages/802.1aj.html) (These documents are attached.) Interpretation #4 was generated, in part, because the development of LLDP-MED pointed out a fault in IEEE Std. 802.1ad Provider Bridges. The result of this Interpretation is that we expect that LLDP-MED will work as intended. A device commonly being supplied by a number of vendors is an IP telephone with two Ethernet ports, that can be inserted between a workstation and a network node. P802.1aj specifies a Two-Port MAC Relay with two external ports and an internal interface to a management stack. It relays frames from one port to the other. It is considerably simpler than an 802.1Q Bridge. For example, 802.1 Bridge Protocol Data Units (BPDUs) and 802.1X Port Authentication PDUs pass transparently through a P802.1aj TPMR; it participates in neither the spanning tree protocols nor the authentication protocols. It does, however, participate in 802.1AB LLDP. Furthermore, there is an option whereby the TPMR's management stack can be accessed through only one of the TPMR's two ports. P802.1AB-REV will be defining multiple destination MAC addresses that can be used with LLDP PDUs. Multiple instances of LLDP can be run, sending and receiving on these different addresses, and thus operating over different ranges. For example, if a P802.1aj TPMR were placed between a workstation and a bridge or router, the TPMR but not the bridge would be visible to an LLDP instance in the workstation using the standard LLDP address, but the bridge and not the TPMR would be visible to another LLDP instance in the workstation using a new LLDP address. An 802.1aj TPMR could have more than a management stack on its management port. In particular, it could be a complete IP telephone stack. IEEE 802.1 invites TIA TR-41.4 to examine the referenced Interpretation and Draft Standards to see whether the P802.1aj TPMR would be a suitable model for a two-port IP telephone. This seems a likely choice for an IP telephone, because it is simpler for the vendor, the network administrator, and the user, than modeling an IP telephone after a full 802.1Q bridge. Given the amount of activity in the bridging area by 802.1, ITU-T, and others, our cooperation will be important in the future. We invite and encourage further participation in the development of P802.1AB-REV and P802.1aj by TIA TR-41.4 members.