TCP Layer Proto Flashcards
(22 cards)
protocol used on top of IP to ensure reliable transmission of packets; prevents problems from occurring;
connection-oriented transport achieved by means of sequence and acknowledgment numbers
it’s fields maintain order and assure receipt of TCP datagram packets, which in turn frees up the upper layer protocol and applications from having to ensure delivery of data transmitted over the network
TCP transport transmission control protocol
SYN/ACK types of handshakes;
guarantees data makes it to and from where you want to send it to
TCP
current block’s positions in the overall TCP datagrams
sequence number
specifies the next sequence number the sender is expecting;
sender’s sequence number is +1
Acknowledgement number
represents the number of 32-bit words that are in the TCP header. This field is used to identify the start of the data field
data offset
number of bytes that the sender accepts from the other end
window size
calculates using the TCP header, Payload and the Pseudo-Header (Source IP, Destination IP, and Protocol number (0x06))
checksum
**max segment size, in conjunction with window size;
max MTU extends;
Minimum length 20, max 60
TCP options
used to indicate a particular state of connection or to provide some additional useful information like troubleshooting purposes or to handle a control of a particular connection
flags
waits for some time for application layer to send enough data equal to maximum segment size so that the number of packets transmitted on the network is minimized
PSH(push)
byte offset (start byte) for TCP Flags?
13
**is the first part of the handshake
SYN
data is forwarded to app layer immediately
URG (URG = 1 flag)
**_______ is required for ipv6, but not for ipv4
checksum
connectionless, focused on speed, unlike TCP which has a connection/connection-oriented;
fast delivery of data; detects corrupt data in packets, but does not attempt to solve it;
used for broadcast
UDP
does not support broadcasting because it needs a handshake;
packets arrive at receiver because we sequence them;
more reliable
TCP
p0f OS fingerprinting is looking at the TCP _______
window size
communicating devices should establish a connection before transmitting data and should close the connection after transmitting the data;
extensive error checking- flow control and ack/sequencing of data;
slower but more reliable;
Re-transmission of lost packets is possible;
20-60 byte variable length header
TCP
used by HTTP, HTTPs, FTP, SMTP and Telnet
TCP
datagram-oritented protocol for broadcast & multi-cast network transmission;
delivery of data is not guaranteed;
simpler, faster,
basic error checking;
no re-transmission/resending of lost packets;
8 byte fixed-length header;
used by DNS, DHCP, TFTP, SNMP, RIP, and VoIP;
no sequencing
UDP
HTTPS and HTTP primarily use
TCP
used by DNS, MDNS, DHCP, TFTP, SNMP, RIP, and VoIP;
no sequencing
UDP
