2.5 Gbps Ethernet slowing down

 I was having issues again with the unexpected slowness of my internet access.  This time turns out due to failure in ethernet auto-negotiation.  My PC's ethernet interface is 2.5 Gbps, as well MoCA adapter that is connected to it.  It was working fine, until yesterday, where I got only 90's Mbps on SpeedTest.

There is cool PowerShell command to display the link speed: Get-NetAdapter.

We can create a DOS shell wrapper, so invoking this from a regular DOS prompt would work.

For example, I put this command in a file called "getnet.ps1".  I created another DOS script called "getnet.cmd" with the content of it just calling getps1.ps1:

In getnet.ps1:

Get-NetAdapter

In getnet.cmd:

call getnet.ps1

For example:

C:\Users\anon\bin>type getnet.cmd

call getnet.ps1

C:\Users\lshih\bin>getnet

C:\Users\lshih\bin>call getnet.ps1

Name                      InterfaceDescription                    ifIndex Status       MacAddress             LinkSpeed

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

Bluetooth Network Conn... Bluetooth Device (Personal Area Netw...      27 Disconnected 38-FC-98-13-E9-2A         3 Mbps

2.5 GigE LAN              Realtek Gaming 2.5GbE Family Contr...#2      21 Up           04-42-1A-0C-2C-C4       2.5 Gbps

vEthernet (2.5 GigE LAN)  Hyper-V Virtual Ethernet Adapter             16 Up           00-15-5D-76-F1-69        10 Gbps

vEthernet (1 GigE LAN)    Hyper-V Virtual Ethernet Adapter #3          52 Up           00-15-5D-D2-5B-EB        10 Gbps

1 GigE LAN                Intel(R) I211 Gigabit Network Conn...#2      14 Up           04-42-1A-0C-2C-C3         1 Gbps

vEthernet (VirtualBox ... Hyper-V Virtual Ethernet Adapter #2          40 Up           00-15-5D-F1-53-24        10 Gbps

VirtualBox Host-Only N... VirtualBox Host-Only Ethernet Adapter         7 Up           0A-00-27-00-00-07         1 Gbps

vEthernet (WSL)           Hyper-V Virtual Ethernet Adapter #4          75 Up           00-15-5D-9C-4E-D0        10 Gbps

Chinese Hackers are now the top of the list

 My gateway router has a cool security feature called Intrusive Threat Prevention (ITS).  When I checked the statistics from where most of the attacks occurred to my gateway, majority the attacks come from China.

What is the maximum Transmit Power sent by 5G Iphone?

 I have been wondering so far how much power a 5G phone, like iPhone 12, can transmit to RAN (Radio Access Network), a.k.a. a base station.

According to the table in standard document ETSI TS 138 101-1, section 6.2.1 for "UE maximum output power", the maximum power for class 2 is 26 dBm (0.398 Watt) and for class 3 is 23 dBm (0.199 Watt).  Class 2 UE (User Element) only transmits at certain frequency bands only, namely n41, n77, n78, and n79, while class 3 transmits in all spectrums.

As stated, the period of measurement shall be at least one sub-frame (sfn, 1ms). 

The above maximum value is rarely reached unless the signal reception by UE or BS (Base station) is too weak.

To understand what are those NR bands, see 5G NR frequency bands - Wikipedia