Author: lechuck park

AI Infrastructure Architect & Technical Visualizer "Complex Systems, Simplified. I translate massive AI infrastructure into visual intelligence." I love to learn computer tech and help people by the digital.

Why TCP is reliable? ( first. theory side)

Posted on by lechuck park

Many people say ” TCP is more reliable than UDP”. almost know it. but. I think many people don’t  know the why in details.

before starting. please keep this concept in your mind. “Packets are sent and received on the computer network.. this means all data is packaged  by packet on the network ”

now. let’s start it for understand about it..

Reliable mean “arrange the sequence order ” on this issue. Please think about it “what kinds of thing is need for it?? ”

  1. each must know when the start is or when the end is of communications.
  2. the value of sequence.
  3. the storage for rearrange the received data which is not processed.

that’s all, and please check the below TCP header. could you figure out what field is for TCP Reliability?

tcp header에 대한 이미지 검색결과

and let’s see the below that matched fields for.. the reliable conditions those described before.

1. each must know when the start is or when the end is of communications.

TCP Connection Procedure (3-hand shaking ) with TCP Flags ( SYN, FIN, RST )

2. the value of sequence.

TCP managed Data sequence with Sequence Number, Ack Number.

3. the storage for rearrange the received data.

TCP buffer is controlled by TCP window (  window field and Window Option about window scale value -> Window ^ Window Scale value => Total Remain buffer size now )

I hope you got the understand it… I will update this page and add more easier example for it.

Do you know ‘Preamble on datagram’ ?

Posted on by lechuck park

before about 10 years ago. Someone ask a question “Do you know Preamble” ?

But I don’t know about it at that time. even though I thought I know almost about TCP/IP packet.

first. you can check details at wiki page

https://en.wikipedia.org/wiki/Ethernet_frame

Anyway I have some insights of it now.

first. Preamble is not on the L3/L4 Layer. It was for L1 layer . so I hadn’t seen it, though I managed Huge TCP/IP packet on Real network . I only checked packet on Ethereal..( now wireshark ).

*Preamble is for synchronization of physical packet to notify the start of Packet. and the Packet is ended by *Interpacket Gap

*Preamble  is like “Syn packet on TCP/IP”, “Hello whenever we meet “, “Delimiter”.

at the result… All Conversation is started with The Synchronization Procedure…..

ready to use vim for python on windows

Posted on by lechuck park

# download & install vim

you can download it on vim.org

# run gvim.exe as administrator ( maybe. here C:\Program Files (x86)\Vim\vim74 )

– edit >> start config  on menu ( windows )

– add 3 lines ( first 2 lines is not mandatory.. it’s just for my coding style )

set ts=4

set autoindent

nnoremap :exec ‘!python’ shellescape(@%,1)<cr

# now ! you can run python file on vim with funtions keys

# add some …

colorscheme darkblue

How to install Tensorflow with Anaconda in Windows 7

Posted on by lechuck park

# Anaconda Download & installl

https://www.continuum.io/downloads#windows

 

 

# check this site

https://www.tensorflow.org/get_started/os_setup

 

# execute cmd.exe as administrator

C:\Windows\system32>

 

# upgrade pip first

C:\Windows\system32> python -m pip install –upgrade pip

 

# upgrade setup tools ( with –ignore-installed if having problem concerned with nonexistent file : easy-install.pth )

C:\Windows\system32> python -m pip install –upgrade setuptools –ignore-installed

 

# and install Tensorflow ( on the checksite on tensorflow homepage _above link)

– below one is for non cuda. if you have nVidia card, check another option on the guide page.

C:\Windows\system32>pip install –upgrade https://storage.googleapis.com/tensorf
low/windows/cpu/tensorflow-0.12.1-cp35-cp35m-win_amd64.whl