A protocol describes a set of rules or procedures that a given task must follow. It identifies the conventions that work on an object, such as how to make connections for communication or file transfer, or connectivity. However, it is silent about how to perform the operations, only stating what they are. Here are three protocols: transfer, e-mail and program development.
Transfer protocols move files and data from one location to another. Two computers in the operation are required: one is a transferring server and the other a receiving client. Several file transfer protocols include the following:
FTP (file transfer protocol) allows the transfer of files. It establishes a connection to a remote client and transfers the files until completed, and then it disconnects. The connection can be in an internal network or over the Internet. Developed in 1971, this protocol served as one of the objectives for the development of the Internet.
Xmodem is an alternative to the FTP protocol. It was popular with bulletin board services in the late 1970s because of its simplicity and ease of use.
Kermit is a binary (0's and 1's) and text file transfer protocol designed in the early 1980s. For the transfer to occur a file conversion takes place to binary format before transmittal and then converted back afterwards. This allowed for file transfers over dissimilar systems.
The advantage of these file transfer protocols is that they share information between different computer systems and different formats.
The Internet Message Access Protocol (IMAP) allows an e-mail client to access e-mail messages on a remote e-mail server.
IMAP supports two modes of operation: online and offline. In online mode, e-mail clients using IMAP leave the e-mail messages on the server until the user purposely deletes them. In offline mode, the e-mail is downloaded and then deleted. This characteristic of the IMAP operation allows multiple clients to manage the same mailbox. The upshot is that the mail stays on the server automatically until deleted.
POP (Post Office Protocol) is an alternate e-mail protocol that supports simple download and delete for access to remote mailboxes. Most POP clients have an option to leave e-mail on the server after download. However, e-mail clients typically follow this procedure. They connect to the server, retrieve their messages, store them on the user's local PC and then delete them from the server and disconnect. The upshot is, the mail is automatically deleted unless kept.
The advantage of both of these protocols is enhanced e-mail management.
Software Developer Protocols
Software developers use protocols in their work. Platform-based database protocols like JDBC (Java DataBase Connectivity) or ADO (active x database objects) have a performance advantage. Also, flexibility and reuse are two main advantages of using a neutral platform protocol such as SOAP (Simple Object Access Protocol).This is a protocol specification that facilitates the exchange of structured information in web services.
By using protocols, software architects and program developers can determine the opportunity cost of the project, that is, whether the development is going to be faster versus whether the program is going to be faster. These performance versus flexibility alternatives affect the coding decision, which impacts the way the program will run.
The advantage of using these protocols is that they improve the performance of programs and provide flexibility in program design.