Retro networking / WAN communities

Paul Koning paulkoning at comcast.net
Mon Apr 11 19:16:48 CDT 2022



> On Apr 11, 2022, at 6:07 PM, Grant Taylor via cctalk <cctalk at classiccmp.org> wrote:
> 
> On 4/11/22 2:58 PM, Paul Koning via cctalk wrote:
>> I don't have a 10Base2 switch, but I have an old repeater with 4-5 10BaseT ports and a 10Base2 port.  And I have a 10Base2 transceiver (as well as 2 or 3 10BaseT transceiver).  Good thing because the Pro has an AUI connector.
> 
> I have to ask ...
> 
> Q1  Would you be referring a "hub"?

I think "hub" is another word for "repeater" (just like "switch" is another word for "bridge").  The device I have is a small standalone box, about the size of today's small 4-6 port switches you buy at Staples for $100.  But it's actually a repeater, not a switch, and one of its ports is a 10Base2 connector (BNC jack).

> Q2  Are your transceivers from AUI to 10Base2 / 10BaseT?  Or are they something else more mid-span?

AUI connector, yes.  Two are little boxes about the size of the connector body but maybe 2-3 inches long, with the coax or RJ45 connector at the other end.  The 10BaseT is a DEC product, the 10Base2 I don't remember.  I also have an ancient 10BaseT transceiver that's about twice as big, with a jack for an external power source, forgot the maker of that one.

> Sorry if this is too pedantic.  But I do feel like the pedantry is somewhat warranted for this list.

You won't get an argument from me on that one... :-)

>> Same here, except unmanaged.  I didn't realize until years into the 1G era that 1G is backwards compatible TWO generations, not the usual one. And the switch seems to be happy to speak 10 Mb half duplex, nice.
> 
> I'm running into issues with switches not supporting 10 / 100 Mbps management interfaces for other equipment.

That's rather odd because even if someone doesn't obey the letter of the law you'd think they would at least support 100BaseT. Or was the problem lack of half duplex?  Do those management interfaces want to run half duplex?

I think I saw in the standard that Gigabit Ethernet in theory includes a half duplex mode, but I have never seen anyone use it and I wonder if it would work if tried.  Perhaps I misread things.

	paul




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