[c-nsp] Galvanic isolation for Ethernet?

[Victor Sudakov]

Howard Jones wrote:
> >
> > Do you know any devices to provide galvanic isolation for twisted pair
> > Ethernet?
> >
> > We have regular Ethernet surge protection devices (AFAIK APC) between
> > the switch and the attached equipment but they don't help. This is the
> > second Catalyst already with a burnt group of ports.
> >
> > Any advice is appreciated.
> >
> An SFP and some multimode fibre? (or a media converter to do the same - 
> Gig-E media converters are cheap)

The devices (surveillance cameras, security sensors, portservers etc)
have 10BASE-T and 100BASE-T interfaces, so this would mean two
converters per device, and converters need to be powered... Too
complicated. I have already thought of that and found unfeasible.

> 
> What happens in the environment between the two devices? Is it passing 
> outside, or between buildings or something else?

Yes, sometimes the cable passes outside and sometimes between
buildings (but never exceeds 100m). Some devices can be grounded, some
not. We thought that APC ProtectNet or similar surge protectors would
be sufficient, but they don't seem to be.


-- 
Victor Sudakov,  VAS4-RIPE, VAS47-RIPN
sip:sudakov at sibptus.tomsk.ru