Computer Network Unit 1 q what are the topologies in computer n/w ?

Streaming of data:	Data is read as a byte stream, no distinguishing indications are transmitted to signal message (segment) boundaries.
Packets are sent individually and are checked for integrity only if they arrive. Packets have definite boundaries which are honored upon receipt, meaning a read operation at the receiver socket will yield an entire message as it was originally sent.
Speed of transfer:	The speed for TCP in comparison with UDP is slower.	UDP is faster because there is no error-checking for packets.
Examples:	HTTP, HTTPs, FTP, SMTP Telnet etc...	DNS, DHCP, TFTP, SNMP, RIP, VOIP etc...
Data Reliability:	There is absolute guarantee that the data transferred remains intact and arrives in the same order in which it was sent.	There is no guarantee that the messages or packets sent would reach at all.
Connection Reliable:	Two way Connection reliable	one way Connection Reliable
Ordering:	TCP rearranges data packets inthe order specified.	UDP does not order packets. If ordering is required, it has to be managed by the application layer.

Q 8. Explain TCP/IP refrence model with functions of each layer ?
Ans: The TCP/IP model :
TCP/IP is based on a four-layer reference model. All protocols that belong to the TCP/IP protocol suite are located in the top three layers of this model.
As shown in the following illustration, each layer of the TCP/IP model corresponds to one or more layers of the seven-layer Open Systems Interconnection (OSI) reference model proposed by the International Standards Organization (ISO).

The types of services performed and protocols used at each layer within the TCP/IP model are described in more detail in the following table.