SG Broadband Community

Good morning

I have a 1 Gb fiber connection, win 7 and Chrome 109 and I set TCP Optimizer with these data:

Chose settings: Optimal
Connection speed = 100+Mbps
MTU = 1500
Autotuning TCP = Normal

I checked with SG TCP/IP Analyzer, with these results:
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« SpeedGuide.net TCP Analyzer Results »
Tested on: 2023.01.20 11:59
IP address: 95.251.xxx.xxx
Client OS/browser: Windows 7 (Chrome 109.0.0.0)

TCP options string: 020405b401010402
MSS: 1460
MTU: 1500
TCP Window: 64240 (multiple of MSS)
RWIN Scaling: 0 bits
Unscaled RWIN : 64240
Recommended RWINs: 64240, 128480, 256960, 513920, 1027840
BDP limit (200ms): 2570 kbps (257 Kilobytes/s)
BDP limit (500ms): 1028 kbps (103 Kilobytes/s)
MTU Discovery: ON
TTL: 119
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)
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I noticed the TCP Window value at 64240, when it should be with BPD calculator with 1Gbit fiber and 5ms average latency, at least 625000.

I ask for your help to understand what this value depends on and how to raise it.
NB: Before the fiber i had a 7 Mbps ADSL.

Thanks to whoever can help me.

Newer Windows variants only show the "current" RWIN value, rather than the maximum, and then the autotuning algorithm scales it up as necessary depending on line conditions. I wouldn't worry about the Analyzer showing a smaller value.

Thanks Philip. For information, I set TCP autotuning to Experimental, but I encountered some problems: sometimes the download speed drops considerably and then rises again and also the Ookla app from PC doesn't work.

Thanks again for the reply.