Loebdaka's Journal: Protocol

Kermit - File Transfer/Management Protocol

Kermit is a computer file transfer/management protocol and a set of communications software tools; it provides a consistent approach to file transfer, terminal emulation, script programming, and character set conversion across many different computer hardware and OS platforms.

The Kermit protocol allows for transferring text and binary files on both full-duplex and half-duplex 8 bit and 7-bit serial connections in a system- and medium-independent fashion, and is implemented on hundreds of different computer and operating system platforms. On full-duplex connections, a sliding window protocol is used with selective retransmission which provides excellent performance and error recovery characteristics. On 7-bit connections, locking shifts provide efficient transfer of 8-bit data. When properly implemented, as in the Columbia University Kermit Software collection, performance is equal to or better than other protocols such as ZMODEM, YMODEM, and XMODEM, especially on poor connections. Unlike XMODEM and its successors, Kermit can be configured to run on connections over Statistical Multiplexors and the like, where some control characters may not be transmissible.

Please visit the full description and commands here.

By at April 17, 2007
Labels: Protocol

Common FTP Commands

Several common ftp commands:

? = to request help or information about the FTP commands

ascii = to set the mode of file transfer to ASCII (this is the default and transmits seven bits per character)

binary = to set the mode of file transfer to binary (the binary mode transmits all eight bits per byte and thus provides less chance of a transmission error and must be used to transmit files other than ASCII files)

bye = to exit the FTP environment (same as quit)

cd = to change directory on the remote machine

close = to terminate a connection with another computer

delete = to delete (remove) a file in the current remote directory (same as rm in UNIX)

get = to copy one file from the remote machine to the local machine

help = to request a list of all available FTP commands

lcd = to change directory on your local machine (same as UNIX cd)

ls = to list the names of the files in the current remote directory

mkdir = to make a new directory within the current remote directory

mget = to copy multiple files from the remote machine to the local machine; you are prompted for a y/n answer before transferring each file
mget * copies all the files in the current remote directory to your current local directory, using the same filenames. Notice the use of the wild card character, *.

mput = to copy multiple files from the local machine to the remote machine; you are prompted for a y/n answer before transferring each file
open to open a connection with another computer
open brubeck opens a new FTP connection with brubeck;
you must enter a username and password for a brubeck account
(unless it is to be an anonymous connection).

put = to copy one file from the local machine to the remote machine

pwd = to find out the pathname of the current directory on the remote machine

quit = to exit the FTP environment (same as bye)

rmdir = to to remove (delete) a directory in the current remote directory Read more »

By at March 25, 2007
Labels: Protocol

What is POP3 server?

Understanding POP3

POP3 (Post Office Protocol 3) is the latest version of the standard protocol for receiving email. POP3 is a client / server protocol where email is sent from the server to local email. Used to communicate with e-mail servers and download all e-mail to local e-mail (such as Outlook, Thunderbird, Windows Mail, Mac Mail, and so on), without storing them on the server. Usually, in an email application there is an option to keep the downloadable email on the server or not.

If you access the same e-mail from different devices, we are very helpful for you to keep a backup. This needs to be done as a precaution, such as the second device does not download the email, while the first device has deleted it.

POP3 is a one-way communication protocol, which means data is retrieved from the server and sent to local e-mail on your computer device.

Default POP3 port

Port 110 - Unencrypted port
Port 995 - SSL / TLS port, other names POP3S

Pros of Using POP3

Once the email can be downloaded by the local mail application on your computer, you don't need to be connected to the internet and you want to open it again.
Mostly there is no size limit for sent and received email.
Can open file attachments quickly.
There is no maximum size for a mailbox, unless your computer hard drive is full.

Disadvantages of Using POP3

If JavaScript in the email reader is enabled, phishing emails with JavaScript embeds can be read in the email.
All messages will be saved on the computer. This can reduce space on the computer hard drive.
All file attachments are stored and stored on the computer. Therefore, the potential for computer virus infection from email is greater.
Email folders sometimes get lost. If this is the case, recovery efforts are quite difficult.

By at March 15, 2007
Labels: Email Administration, Protocol

FTP - File Transfer Protocol

Short for File Transfer Protocol, the protocol for exchanging files over the Internet. FTP works in the same way as HTTP for transferring Web pages from a server to a user's browser and SMTP for transferring electronic mail across the Internet in that, like these technologies, FTP uses the Internet's TCP/IP protocols to enable data transfer. FTP is most commonly used to download a file from a server using the Internet or to upload a file to a server (e.g., uploading a Web page file to a server). Specifically, FTP is a commonly used protocol for exchanging files over any network that supports the TCP/IP protocol (such as the Internet or an intranet).

There are two computers involved in an FTP transfer: a server and a client. The FTP server, running FTP server software, listens on the network for connection requests from other computers. The client computer, running FTP client software, initiates a connection to the server. Once connected, the client can do a number of file manipulation operations such as uploading files to the server, download files from the server, rename or delete files on the server and so on.

Any software company or individual programmer is able to create FTP server or client software because the protocol is an open standard. Virtually every computer platform supports the FTP protocol. This allows any computer connected to a TCP/IP based network to manipulate files on another computer on that network regardless of which operating systems are involved (if the computers permit FTP access). There are many existing FTP client and server programs.

By at March 14, 2007
Labels: Protocol