Transport layer Chap 7 Flashcards
What are the 3 primary responsibilities of the transport layer?
- Tracking the individual communication between applications on the source and destination hosts
- Segmenting data for manageability and reassembling segmented data into streams of application data at the destination
- Identifying the proper application for each communication stream
What are the 2 transport layer protocols?
TCP and UDP
reliable, full-featured transport layer protocol, which ensures that all of the data arrives at the destination
TCP
very simple transport layer protocol that does not provide for any reliability.
UDP
3 basic operation of reliability in TCP?
- Tracking transmitted data segments
- Acknowledging received data
- Retransmitting any unacknowledged data
What are the units that the TCP message breaks into smaller pieces called?
segments
is known as a best-effort delivery protocol
UDP
transport layer protocol that is a better choice for applications that can tolerate some data loss during transmission over the network, but delays in transmission are unacceptable
UDP
TCP segment header Used for data reassembly purposes.
sequence number 32bits
TCP segment header that Indicates the data that has been received.
Acknowledgement number 32bits
Known as ʺdata offsetʺ. Indicates the length of the TCP segment header.
header length 4bits
Field received for future use in a TCP header
Reserved 6bits
includes bit codes, or flags, that indicate the purpose and function of the tcp segment header
control bits 6bits
Indicates the number of segments that can be accepted at one time in a TCP segment header
window size 16bits
used for error checking of the segment header and data in a tcp segment header
checksum 16bits
TCP segment header that Indicates if data is urgent
Urgent 16bits
What are the 4 udp header fields?
source, destination, length, checksum
what 2 addresses make up a socket?
ip address and port number
What ports are the well know ports?
0 to 1023
what ports are the Registered ports
1024 to 49151
what ports are the dynamic or private ports
49152 to 65535
port used for ftp
21 tcp
port used for telnet
23 tcp
port used for smtp
25 tcp
port used for https
443 tcp
port used for internet relay chat
194 tcp
port used for imap
143 tcp
port used for http
80 tcp
port used for tftp
69 udp
port used for rip
520 udp
port used for dns
53 tcp/udp
port used for snmp
161 tcp/udp
port used for aim/irc
531 tcp/udp
what 5 things do the netstat command show?
protocol used, source port, address or name of remote host, destination port, connection state
