Hello, here are my results, how do i can modify settings on my Mac Pro ?

SpeedGuide.net TCP Analyzer Results
Tested on: 2017.12.14 12:32
IP address: 181.169.xxx.xxx
Client OS/browser: Mac OS (Firefox 56.0)

TCP options string: 020405b4010303050101080a01bc751b0000000004020000
MSS: 1460
MTU: 1500
TCP Window: 131744 (not multiple of MSS)
RWIN Scaling: 5 bits (2^5=32)
Unscaled RWIN : 4117
Recommended RWINs: 64240, 128480, 256960, 513920, 1027840
BDP limit (200ms): 5270kbps (659KBytes/s)
BDP limit (500ms): 2108kbps (263KBytes/s)
MTU Discovery: ON
TTL: 48
Timestamps: ON
SACKs: ON
IP ToS: 00000011 (3)
Precedence: 000 (routine)
Delay: 0 (normal delay)
Throughput: 0 (normal throughput)
Reliability: 0 (normal reliability)
Cost: 1 (low cost)
Check bit: 1 (incorrect)
DSCP (DiffServ): CS0 000000 (0) - class 0, default traffic (RFC 2474).

Thanks a lot.
mito