Попробуйте померять iperf-ом и с UDP.

выше приводил статистику для iperf.

Ключ -u попробуйте.

C:\>C:\iperf.exe -s -u
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 byte datagrams
UDP buffer size: 8.00 KByte (default)
------------------------------------------------------------
[1928] local 10.2.2.170 port 5001 connected with 10.2.2.160 port 1075
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[1928] 0.0-10.0 sec 1.21 MBytes 1.02 Mbits/sec 0.000 ms 27/ 893 (3%)
[1928] local 10.2.2.170 port 5001 connected with 10.2.2.160 port 1078
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[1928] 0.0-10.0 sec 1.21 MBytes 1.02 Mbits/sec 0.017 ms 28/ 893 (3.1%)
[1928] local 10.2.2.170 port 5001 connected with 10.2.2.160 port 1080
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[1928] 0.0-10.0 sec 1.21 MBytes 1.01 Mbits/sec 0.000 ms 29/ 893 (3.2%)
[1928] local 10.2.2.170 port 5001 connected with 10.2.2.160 port 1083
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[1928] 0.0-30.0 sec 3.63 MBytes 1.02 Mbits/sec 0.000 ms 84/ 2676 (3.1%)

Привозите в сервис, будем смотреть.