Thanks for advice.
Here is the iperf3 test results
Connecting to host xyz.example.com, port 6000
[ 4] local XXX.XXX.XXX.XXX port 36140 connected to XYZ.XYZ.XYZ.XYZ port 6000
[ ID] Interval Transfer Bandwidth Retr Cwnd
[ 4] 0.00-1.00 sec 81.9 MBytes 687 Mbits/sec 0 352 KBytes
[ 4] 1.00-2.00 sec 80.5 MBytes 676 Mbits/sec 0 352 KBytes
[ 4] 2.00-3.00 sec 80.5 MBytes 676 Mbits/sec 0 362 KBytes
[ 4] 3.00-4.00 sec 79.8 MBytes 669 Mbits/sec 0 362 KBytes
[ 4] 4.00-5.00 sec 80.6 MBytes 676 Mbits/sec 0 362 KBytes
[ 4] 5.00-6.00 sec 82.0 MBytes 688 Mbits/sec 0 362 KBytes
[ 4] 6.00-7.00 sec 81.3 MBytes 682 Mbits/sec 0 362 KBytes
[ 4] 7.00-8.00 sec 80.5 MBytes 676 Mbits/sec 0 362 KBytes
[ 4] 8.00-9.00 sec 80.5 MBytes 676 Mbits/sec 0 362 KBytes
[ 4] 9.00-10.00 sec 79.8 MBytes 669 Mbits/sec 0 362 KBytes
Assuming
xyz.example.com is in the display network you need to find out what is throttling you at these values.
Actually, what i was trying to ask is is there any reletion between "default route" and "display" network on oVirt network.
No, they should not be related