Hi All,
Im tracking some strange behaviour but don’t have any clue where to start.
I got 2X 100Mbit link between 2 Datacenter in Load Sharing per Session mode via BGP Multipath.
Its Plain Data via Leased line without MPLS, QOS or IPSEC.
The RTT are approx 350ms.
According to a TCP Window size of 64K i can use only 1.49Kbit per TCP session while the RTT is 350ms.
Maximum Possible Transfer Rate = TCP Window Size/RTT
Where RTT is Ping Response in Millseconds/1000
| RTT | Max Throughput | Max Throughput | |
| 350 mS | 1,496 Kbps | 187.0 KBps | |
see (http://www.mpls-experts.com/why-your-maximum-thru-put-is-less-than-your-bandwidth/)
Due to this 64K Windows i have to start several TCP Sessions to use this 100 or 200Mbit link.
But what’s about "TCP Windows scaling"?
Shouldn’t modern Operating Systems use "TCP Window scaling" to get Window sizes above 64k to transmit more than 1,49Kbit at 350ms?
I need more bandwidth within a single TCP session.
Some hints or Ideas?
Regards
Tracer
