What is the actual bit rate over a network transmitting 100 kbps?

Question

When transmitting, say, 1 GB of data over the Internet, this data is divided into packets, each packet containing a small piece of data and each of these packets is part of the frame.

Eg. Windows reports that you are transferring a file of 100 kbps over a TCP connection, but this is apparently the amount of data from the file being transmitted per second, and does not seem to include the ip or tcp header or Ethernet frame.

What is the actual amount of network traffic needed to transmit at this speed? Or is this data actually already included in the data transfer rate, but small enough not to have a significant difference?

In addition, IP supports up to 1500 bytes / packet (I think?), But what is the total size of data packets when uploading, say, HD images to reddit?

Sorry for the pretty simple questions that I probably should have guessed so far ...

Answer 1

It depends on where you look at the baud rate:

• The task manager will report all bytes transferred (i.e. the sum of all packets, including their headers).
• The file transfer program will report the transferred payload.

Task Manager

If you look at the Task Manger / Network, you can see the transmitted bytes along with the number of packets transmitted (unicast or non-unicast).

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( jumbo frames), TCP- ( Ethernet-) 1500 ( (IPv4) 1514 54 - 14 Ethernet-, 20 IP 20 TCP). , .

( ) 2 (1514 ) 1 (54 ) ( [ACK]). 2 x 1460 2 x 54 + 54 . -, .

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• (, 4096 ). 2 x 1460 1 x 1176, .

transfer_bytes/ . - ( , ), API-, , (, jumbo-).

Answer 2

TCP/IPv4 1500B ( (MTU)), () 20B TCP- () 20B IPv4. MTU Ethernet. , (, HTTP , SIP/RTP/RTCP ..). MTU 576B IPv4 1280B IPv6. MTU Linux ifconfig.

pcap/ , Wireshark. .

Answer 3

I am sure that the reported forwarding speed does not include all the headers and overhead at different levels in the protocol stack, since the reported thruput usually comes from some user space application that will only receive actual data from the network stream object. He will need to do additional work to find out about all the headers and frames and other overheads that have occurred in different layers and that have affected the actual physical transfer.