Module 3 - Protocols and Models Flashcards
Role of Protocols
In addition to identifying the source and destination, computer and network protocols define the details of how a message is transmitted across a network. Common computer protocols include the following requirements:
Message encoding
Message formatting and encapsulation
Message size
Message timing
Message delivery options
Encoding / Decoding
Encoding is the process of converting information into another acceptable form, for transmission. Decoding reverses this process to interpret the information.
Flow Control
This is the process of managing the rate of data transmission. Flow control defines how much information can be sent and the speed at which it can be delivered. For example, if one person speaks too quickly, it may be difficult for the receiver to hear and understand the message. In network communication, there are network protocols used by the source and destination devices to negotiate and manage the flow of information.
Response Timeout
Hosts on the network use protocols that spedify how long to wait for responses and what action to take if a respoinse timeout occurds
Access method
When a device wants to transmit on a particular medium, the NIC determines whether the medium s available.
Which step of the communication process is concerned with properly identifying the address of the sender and receiver?
Formatting
Network Communications Protocols
Protocols enable two or more devices to communicate over one or more networks. The Ethernet family of technologies involves a variety of protocols such as IP, Transmission Control Protocol (TCP), HyperText Transfer Protocol (HTTP), and many more.
Network Security Protocols
Protocols secure data to provide authentication, data integrity, and data encryption. Examples of secure protocols include Secure Shell (SSH), Secure Sockets Layer (SSL), and Transport Layer Security (TLS).
Routing Protocols
Protocols enable routers to exchange route information, compare path information, and then to select the best path to the destination network. Examples of routing protocols include Open Shortest Path First (OSPF) and Border Gateway Protocol (BGP).
Service Discovery Protocols
Protocols are used for the automatic detection of devices or services. Examples of service discovery protocols include Dynamic Host Configuration Protocol (DHCP) which discovers services for IP address allocation, and Domain Name System (DNS) which is used to perform name-to-IP address translation.
Network Protocol Functions
Addressing, Reliability, Flow control, Sequencing, Error Detection, Application Interface
Addressing
This identifies the sender and the intended receiver of the message using a defined addressing scheme. Examples of protocols that provide addressing include Ethernet, IPv4, and IPv6.
Reliability
This function provides guaranteed delivery mechanisms in case messages are lost or corrupted in transit. TCP provides guaranteed delivery.
Flow control
This function ensures that data flows at an efficient rate between two communicating devices. TCP provides flow control services.
Sequencing
This function uniquely labels each transmitted segment of data. The receiving device uses the sequencing information to reassemble the information correctly. This is useful if the data segments are lost, delayed or received out-of-order. TCP provides sequencing services.
Error Detection
This function is used to determine if data became corrupted during transmission. Various protocols that provide error detection include Ethernet, IPv4, IPv6, and TCP.
Application Interface
This function contains information used for process-to-process communications between network applications. For example, when accessing a web page, HTTP or HTTPS protocols are used to communicate between the client and server web processes.
DHCPv4
Dynamic Host Configuration Protocol for IPv4. A DHCPv4 server dynamically assigns IPv4 addressing information to DHCPv4 clients at start-up and allows the addresses to be re-used when no longer needed.
DHCPv6
Dynamic Host Configuration Protocol for IPv6. DHCPv6 is similar to DHCPv4. A DHCPv6 server dynamically assigns IPv6 addressing information to DHCPv6 clients at start-up.
SLAAC
Stateless Address Autoconfiguration. A method that allows a device to obtain its IPv6 addressing information without using a DHCPv6 server
DNS
Domain Name System. Translates domain names such as cisco.com, into IP addresses.
SMTP
Simple Mail Transfer Protocol. Enables clients to send email to a mail server and enables servers to send email to other servers.
POP3
Post Office Protocol version 3. Enables clients to retrieve email from a mail server and download the email to the client’s local mail application.
IMAP
Internet Message Access Protocol. Enables clients to access email stored on a mail server as well as maintaining email on the server.
FTP
File Transfer Protocol. Sets the rules that enable a user on one host to access and transfer files to and from another host over a network. FTP is a reliable, connection-oriented, and acknowledged file delivery protocol.
SFTP
SSH File Transfer Protocol. As an extension to Secure Shell (SSH) protocol, SFTP can be used to establish a secure file transfer session in which the file transfer is encrypted. SSH is a method for secure remote login that is typically used for accessing the command line of a device.
TFTP
Trivial File Transfer Protocol. A simple, connectionless file transfer protocol with best-effort, unacknowledged file delivery. It uses less overhead than FTP.
HTTP
Hypertext Transfer Protocol. A set of rules for exchanging text, graphic images, sound, video, and other multimedia files on the World Wide Web.
HTTPS
HTTP Secure. A secure form of HTTP that encrypts the data that is exchanged over the World Wide Web.
REST
Representational State Transfer. A web service that uses application programming interfaces (APIs) and HTTP requests to create web applications.
TCP
Transmission Control Protocol. Enables reliable communication between processes running on separate hosts and provides reliable, acknowledged transmissions that confirm successful delivery.