Test equip to measure BER in TCP/IP

I have a 100BaseT Ethernet Router to Ethernet Router link over several miles
of fiber using TCP/IP with fixed IP addresses. Nothing in between except
fiber and electrical to optical conversion.

What test equipment is recommended to measure Bit Error Rate from Ethernet
port on one end to Ethernet Port on the other end? Im used to using paired
PRBS generator/receiver gear to measure BER on serial links (such as
Fireberd 6000a), but how is this done on a packet based link? Is there
other equipment that might provide BER or other measurements of link quality
for this point to point link?

Any thoughts appreciated.
Thanks!