OSI Transport Layer Flashcards
this is the layer prepares application data for transport over the network and processes network data for use by applications
Transport Layer
Transport Layer Functions
- Enables multiple applications to communicate over the network at the same time on a single device
- Ensures that all the data is received reliably and in order by the correct application
- Employs error-handling mechanisms
Purpose of the Transport Layer
- Tracking the individual communications between applications
- Segmenting data
- Reassembling of Segments
- identifies correct apps with port numbers
- flow control between end users
- enable error recovery
- initiating a session
- handle diverse data requirements
What is UDP?
User Datagram Protocol
What is TCP
Transmission Control Protocol
TCP vs UDP
- TCP is connection-oriented, UDP is connectionless
- TCP has more overhead, UDP has less overhead
- TCP sends packets reliably, UDP sends segements as best effort
- TCP has bigger segments, UDP is smaller
The standards body that is responsible for assigning various addressing standards
Internet Assigned Numbers Authority (IANA)
Port Numbers for Well-known ports
Numbers 0 - 1023
Port numbers for Registered Ports
Numbers 1024 - 49151
Port Numbers for Dynamic or Private Ports
Numbers 49152 - 65535
these are ports known as ephemeral ports, assigned dynamically to client applications when initiating a connection
Dynamic or Pivate Ports
command used to verify which active TCP connections are open and are running on a networked host
netstat
How does the Transport Layer reassembles segments
By numbering and sequencing the segments, the layer can reassemble the data and directed to the correct application
How does the transport layer identify the Correct application to send the data to
The transport layer must identify the target application through the port numbers
In the Transport Layer, each particular set of pieces flowing between a source and destination app is known as
conversation
It is the job of the Tranport Layer that refers to the regulation of the amount of data the source can transmit as a group when the its aware of the overtaxation of network resources
Flow Control
What is IRC
Internet Relay Chat
What is TFTP
Trivial File Transfer Protocol
RTP
Real-Time Transport Protocol
SIP
Session Initiation Protocol
How does the TCP establish a three-way handshake?
- the client sends an initial sequence value
- server acknowledges the request (client initial value + 1)
- the client acknowledges the message with (server initial value + 1)
It is the amount of data a source can transmit before an ACK must be received
Window Size
Port for FTP (Data)
Port 20 - TCP
Port for FTP (Control)
Port 21 - TCP
