suffering from poor network performance...

[Wes Peters]

On Thursday 18 December 2003 09:07, Robert Watson wrote:
> On Wed, 17 Dec 2003, Wes Peters wrote:
> > On Tuesday 16 December 2003 03:35 pm, Charles Swiger wrote:
> > > On Dec 16, 2003, at 5:58 PM, Alex (ander Sendzimir) wrote:
> > > > I have a small home network with a PowerBook G4 and FBSD
> > > > 4.9-STABLE connected through a Netgear DS108 hub (10/100).
> > >
> > > If the device works at both 10 and 100 speed, it's a switch, not
> > > a hub.
> >
> > This is one of those curious half-breed thingys that were popular
> > for a year or so before the prices of switches fell through the
> > floor.  It's essentially a 10Base-T hub and a 100Base-TX hub in the
> > same box, a relatively simple switch at each port connects
> > "partitions" you the 10 or 100 mbps portion.  They're odd little
> > beasts, you can sniff traffic on them, but only traffic at the same
> > speed you're running at.  If you have two 100Base machines yakking
> > away and try to sniff them from a 10Base machine, you won't see
> > anything.
> >
> > These were typically sold as "Dual Speed" hubs, thus the "DS" in
> > the product id.
>
> I had one of these, and had terrible problems: if there was much
> traffic on the 100mbps side, the 10mbps side essentially got cut off
> from the 100mbps side.  Apparently it starved something inside the
> hub, because traffic basically didn't move from the 100mbps side to
> the 10mbps side even when it was supposed to.  Can't really think of
> a good reason why that would be the case, since 10/100 switches
> generally don't have too many problems with that, but it was a
> disaster.  I ended up buying more 100mbps cards leaving only a
> printer at 10mbps, where interactive performance wasn't an issue.

Queue space.  If you recall, RAM used to be fairly expensive, especially 
fast RAM.  The simple switch between the 10 and 100 mbps hubs, used 
only for broadcast and multicast packets, was typically very small, 
maybe only a few packets in size.  I remember being shocked at how
small it was in the Dayna dual-speed hub, and how much of the cost in
the bill of materials it accounted for.

Good riddance to bad rubbish.

-- 
         "Where am I, and what am I doing in this handbasket?"

Wes Peters                                              wes at softweyr.com