Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
Name 5 features supported by TCP / UDP |
Multiplexing - This is where ports arw used to know what application recieves the data
Error recovery(reliabilty) - where data is resent if not acknowledged by reciving host. With sequence and ACK fields
Flow control - limit the amount of data that can be sent by Window size. Prevents comgestion
Connection establishment- process used to intialise port number and Seq and Ack fields
Ordered Data transfer- continuous stream of bytes from upper layer processes . Segmented to the upper layers of the receiving device
|
Mutiplexing |
|
|
Explain multiplexing |
This is where the receiving device knows what application to send the received data. By using a Socket |
SOCKET |
|
|
Name the three items of the socket |
IP Address. Transport Protocol . PORT number IP address is given fromt the IP header. Transport protocol is implied. Byt the protocol used. So only the port number is the field |
|
|
|
What is connection esbalishment? |
Devices need to exchange messages before any data is transferred. Referes to initialising Sequence and Ack fields and port numbers to be used |
|
|
|
Describe the 3 way handshake |
Syn Syn, Ack Ack. This uses the 2 bit in the flag field of the TCP header |
|
|
|
Name the messages sent to terminate TCP connection |
ACK,FIN ACK ACK. FIN ACK |
|
|
|
What protocol does CIsco use to transfer files between devices and what Protocol to manage cisco devices? |
TFTP - Trivial file transfer Port 69 SNMP - Simple network management protocol Port 161 TELNET Port 23 SSH Port 22 |
|
|
|
Explain Error recovery |
If data is sent via TCP then if a packet is dropped then receiving host notices this and request the packet to be sent again Uses SEQ number and Ack field for both directions |
|
|
|
Define forward acknowledgement |
When the recieving device acknowledges the nexr data byte SEQ to be sent
This also tells the receiving device all data bytes where received ACK always asks for the next data bye to be sent |
|
|
|
Explain Flow Control..Windowing |
This is where the RECEIVING device controls how much data cab be sent before and outstanding ACK. The size is control by the window field in the TCP header. makin the window bigger or smaller is call SLIDING WINDOWS |
|
|
|
Explain UDP benefits? |
Only uses Multiplexing with port numbers Requires less processing and overheads than TCP. Is used for transport of applications that are tolerant of data loss. E.g VoIP |
|
|
|
What part of a URI is the server |
//cisco.com/ |
|
|
|
How does client resolve DNS |
1) Client sends DNS request via UDP to the DNS server to Destination Port 53 2) Server responds to Destination IP (client) as Source IP (Server..in IP Header) with a UDP header (source port 53, Dest port randomly assigned) With the IP addess of the Cisco.com 3) Client send starts up a TCP connection to Cisco.com from the newly learnt address via a tcp header and source port 80 |
|
|
|
What is the HTTP GET command |
When a webserver requests a web page That page may have many references to links ,images etc called objects. The the web browser gets the URI.. then the server sends a OK with data |
|
|
|
How does the browser decide what application to give the recieved data |
By the local port number |
|
