Connection to Server through BigIP slow, connection from Servers VLAN OK: How to troubleshoot?

I do no have a 80 Mbps dump, just the iperf information.

 

Here is a iperf from my client to another location (same Bigip, same server behind), this is "55 Mbps only", there is a 4 ms Leased Line in between.

 

But much better then from my local site an 29 Mbps only:

 

 

C:\iperf>iperf -c 10.172.228.2 -t 10

 

------------------------------------------------------------

 

Client connecting to 10.172.228.2, TCP port 5001

 

TCP window size: 8.00 KByte (default)

 

------------------------------------------------------------

 

[1908] local 10.136.172.202 port 3218 connected with 10.172.228.2 port 5001

 

[ ID] Interval Transfer Bandwidth

 

[1908] 0.0-10.0 sec 66.0 MBytes 55.4 Mbits/sec