> On Oct 4, 2018, at 1:43 PM, Warner Losh <[email protected]> wrote:
>
>
>
> On Thu, Oct 4, 2018 at 11:39 AM Paul Koning via cctalk
> <[email protected]> wrote:
>
>
> > On Oct 4, 2018, at 1:30 PM, Grant Taylor via cctalk <[email protected]>
> > wrote:
> > ...
> > That makes me wonder about the "heartbeat" switch that I see on older AUI
> > transceivers.
>
> Yes, I think that's the collision test. So in the OFF position you have a V1
> compatible transceiver, ON is needed for V2.
>
> Is that the same as SQE? I always had to turn that bad-boy off or risk
> collision storms :(
>
> Warenr
I had to look up SQE. http://www.ethermanage.com/ethernet/sqe/sqe.html It's
802-speak for the same signal.
That page says you have to turn it off for the transceiver connected to an
802.3 repeater, but it should be on in all other cases. Sounds like the 802.3
people got the transceiver design wrong and that rule is a workaround. There
certainly is no similar rule in the Ethernet spec, and repeaters are definitely
part of that spec.
paul
