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Suggested Objectives for the DTE Power Via MDI Study Group from TIA TR-41.3.4


As agreed during the meeting in York, the DTE Power Via MDI Study Group's
five Criteria and proposed Objectives were presented at our meeting on the
eighth of November.   In attendance were 35 Telecommunications Industry
Association members representing a wide cross section of the telecom
industry.  All present expressed support for the project that Study Group
has proposed and will provide input where applicable.

Due to and intense interest in the Study Group's objectives, about half of
the one day meeting was devoted to their discussion and review.  This
resulted in the three suggestions that are attached.  We hope that they can
be considered and included in the final objectives of the Study Group.

Best regards,
	Phil Holland

Suggestions from TR-41.3.4:  Performance and Interoperability Requirements
for Voice-over-IP Telephone Terminals

A.	Common Powering for 10/100/1000BASE T Networks
The TR-41.3.4 working group supports and would like to have additional
emphasis placed on the DTE Power via the MDI Study Groups first two
objectives.  To clarify the emphasis that the working group felt should be
placed on the first objective, the following revised wording was suggested.

	1.	Economically provide power to 10BASE- T and 100BASE- TX
devices, and not preclude powering 1000BASE-T devices.  

	2.	Select one power distribution technique for world-wide use

Today, 10/100BASE-TX networks are common. These will move to 100/1000BASE-T
in the near future.  A power methodology that supports 10/100/1000BASE-T
networks is therefore HIGHLY DESIRABLE.  For this reason, any powering
methodology selected must not preclude 1000BASE-T products in the future.
We recognize the 1000BASE-T networks could be difficult to support.  While
it may not be possible to include 1000BASE-T in the initial version of an
IEEE 802.3 DTE Power via the MDI, future technologies may make this possible
as long as the wiring scheme does not preclude it.  Leaving this option open
is important.

B.	Powering of Intermediate Devices
An additional objective should be to recognize that intermediate devices may
need to be powered via the MDI and in turn pass power on to an endpoint.
These intermediate devices will be required to facilitate the economic mass
deployment of VoIP telephones.

For example, consider a small router placed in an office to connect a VoIP
Telephone, a PC and other devices that require powered or un-powered
connections.  Passing power through such devices is important to provide an
economic means of supplying backup power.  Telephones and their related
network infrastructure must remain operational during a power failure.

C.	Safety Standards
Any powering methodology defined by the Study Group should be compatible
with existing, internationally recognized safety standards. 

 <<Suggested Objectives from TIA TR-41.3.4.htm>> 

Suggested Objectives from TIA TR-41.3.4.htm