What do you mean by NNTP

Hi,

I have seen in many forums the use of word NNTP. I know that its something related to newsgroup, but can you explain me in detail, What do you mean by NNTP ? And also tell me it advantages and disadvantages ???

Network News Transfer Protocol (NNTP) is a network protocol corresponding to the layer under the scheme OSI . It is specified by RFC 977 . This protocol has been revised and completed in October 2006. The RFC 3977 obsoletes RFC 977 . NNTP is used in particular newsgroups Usenet (see this article for a summary description of the protocol). NNTP servers usually listen on port 119 or 563 to exchange encrypted by SSL / TLS (under the name NNTP).

The operation of NNTP is very simple, consisting of a server that are stored therein news and clients connect through the network. The connection between client and server is done interactively and obtaining a number of duplicate articles low. This is a great advantage over previous news services, in which batch technology was its main ally.

This connection is made to the protocol TCP . Port 119 is reserved for NNTP. However, when clients connect to the news server using SSL uses port 563. Each news article is stored on the server referenced by the name of the client machine that has been published that article. This reference is present in a header field called NNTP-Posting-Host.

Like other news servers, customers can list the newsgroups available to download, send and publish articles through the NNTP specific orders. When publishing is creating a new article, and therefore the header of the message will only be part of the information. By submitting you are working on a story that really exists and it has complete information in the header and also contains the ID of the message when it was published. Both news readers such as news transfer clients can download the articles. This allows simultaneous access from many clients to the news, not to mention the major drawbacks of NFS.

The NNTP protocol is based on a sequence of commands and responses in ASCII as SMTP . The communications are usually via port 119 server. The answers returned by a server are divided into two categories in the RFC: Responses to "textual" and answers "states" in the form of numbers. Directions statements identifying whether a command sent by the client has been correctly processed by the server. Parameters can be attached to the ID of the server status. A certain freedom is provided through debug messages. A successful command will return an error code of 2xx (eg, 211 for the GROUP command).

This algorithm protects loops using the numeric identifier of a message, unique and generated by the original server. If the server receives a message with the same identifier, it is rejected. Also, the header of a message contains the entire propagation path thereof, per-server, which lets the server know not to target these other servers at its own recovery.