28 Jun
2023
28 Jun
'23
2:36 p.m.
On Jun 28, 2023, at 9:56 AM, Jonathan Chapman via
cctalk <cctalk(a)classiccmp.org> wrote:
...
3U. But yes, it took some pretty good wizardry to run at that speed with the machinery of
the time, certainly at that cost. Along the same lines, designing the DECbridge-900 was
quite an interesting exercise. While it doesn't run quite at 6 x Ethernet wire speed,
it does manage about 60k packets per second. More importantly, it includes algorithms to
ensure that spanning tree packets are always handled even if the device is presented with
an overload. You can see it in US patent 6,301,224. The DECbridge-900 achieved that
performance with forwarding in software, in a Motorola 68040 at 25 MHz, with a little help
from a 64-entry CAM.
For wiring two 10Mb Ethernet NICs together, a bridge will certainly serve, as will a pair
of transceivers. A repeater will also do the job. Or a DELNI, which isn't
technically a repeater; I don't think it is a device described by the standard at all,
just a piece of magic that interoperates with the standard by suitable magic.
paul
If you want to link 2 transceivers together on
the AUI side then
that's a network bridge. Even a basc one is quite a lot of
electronics.
DEC's full wirespeed bridge was supposedly considered something of an engineering
miracle at the time and occupies 2U of rack space!