Subject: Re: How does 10baseT/FDX work?
To: Justin C. Walker <>
From: Ignatios Souvatzis <>
List: tech-net
Date: 09/25/1999 22:30:11
On Sat, Sep 25, 1999 at 01:25:36PM -0700, Justin C. Walker wrote:
> It may work; I don't know exactly what external loopback does in  
> most devices (and don't have my usual pack of doc with me).  A couple  
> of notes:
>   - external loopback is normally a diagnostic mode, so I don't know  
> if the device would work differently than in "normal mode (does it  
> require a loopback connector?); and

Well, it's defined as "sends and receives at concurrently" for this chip,
this should be good enough. There are no special diagnostic commands to use;
just normal send and receive.

>   - this definitely won't get you N-way (autonegotiation) support,  
> but most (some?) switches are configurable for this feature (finding  
> out about it is another trick).  However, hubs and switches won't  
> default to FDX, so for general use, you're looking at some trouble.   

Oh, yes, I'd need to ask our Master Of The Big Switch Downstairs to
hardwire it.

> If you're using this in a limited, controlled environment, it may  
> work.

Well, I'll do some tests after my vacation week.