We have a vpn with border manager 3.8 on my site and an checkpoint firewall
on the other site.

When I ping from my workstation x to the other workstation y, the ping is
all right.
When on the workstation y pings my workstation x, the ping is all right.

But when we both ping at the same time only one ping will get an answer.

Why can we do not a "duplex ping"?