|Thread Links||Date Links|
|Thread Prev||Thread Next||Thread Index||Date Prev||Date Next||Date Index|
OK, I'll bite,|
I think it has been "shown" that for the purposes of the PAR and 5 critters, 10G will work over the following:
ISO Class F without ammendment.
ISO Class E (or Cat6) screened or SSTP (with extended limits to 500 or 625 MHz) extended limits TBD by ISO or TIA
(note that Class D and Class E screened (overall shield) and SSTP (individually shielded pairs) are commonly installed in Europe, so this is not a "fantasy cable". Screened cabling is also specified by TIA)
ISO Class E (or Cat6) UTP to 50 meters (with extended limits to 500 or 625 MHz) extended limits TBD by ISO or TIA
ISO Class D (Cat5e) Screened? Perhaps up to 80 meters, but this is grey area.
ISO Class D (Cat5e) UTP? Perhaps up to 40 meters,
For ISO Class D (Cat5e) there is a basic problem in that the cabling standards groups are unwilling to standardize (create limits) beyond 100 MHz, or expend further work on the cabling besides measure it. This poses a very real difficulty in specifying a protocol that relies upon performance beyond that specified by the cabling standard. (ask Geoff Thompson) Cabling manufacturers may decide to forego warranting their cabling systems for such a protocol.
Also, for the time being, lets pretend that alien crosstalk field testing does not exist (it doesn't). Also lets pretend that alien crosstalk mitigation techniques (all, retrofit and new cable designs) for the moment do not exist. These are considerations for the task group.
Some may also contend that the protocol will run on longer lengths of Cat5e and Cat6 UTP. If so, that is fine, but it is a matter of dispute, and therefore cannot be considered. This is also a consideration for the task group.
At the Plenary, on the last day we heard the PHY vendors backpedaling on their previously stated opiniion that it would run on Class F. If that is the case, and they insist on this position, then the project is dead. Therefore I propose that there must be an agreement that the protocol will run on at least Class F cabling to 100 meters, or we need to start over. If we can agree on that, then we can move forward to consider the other cabling classes.
Bruce Tolley wrote: