Harley Davidson
CIS 210
Assignments
Submitted by:
Rahul Jwarchan
Stael Kitoto
Merveille Mokweme
Q.1 What are the main differences between OSI and TCP/IP reference models?
Explain briefly.
The main differences between the two models are as follows: -
- OSI is a reference model and TCP/IP is an implementation of OSI model.
- TCP/IP Protocols are considered to be standards around which the Internet has developed. The OSI model however is a “Generic, protocol-independent standard."
- TCP/IP combines the presentation and session layer issues into its application layer.
- TCP/IP combines the OSI data link and physical layers into the network access layer.
- TCP/IP appears to be a simpler model and this is mainly due to the fact that it has fewer layers.
- TCP/IP is considered to be a more credible model- this is mainly due to the fact because TCP/IP protocols are the standards around which the Internet was developed therefore it mainly gains creditability due to this reason. Where as in contrast networks are not usually built around the OSI model as it is merely used as a guidance tool.
- The OSI model consists of 7 architectural layers whereas the TCP/IP only has 4 layers
Q.2 Is TCP checksum necessary or could TCP allow IP to checksum the data?
- Yes, TCP Checksum is necessary.
TCP layer is responsible for error detection, error control, retransmission of packets if required, reassembly of packets as well as their fragmentation. Hence for all error control and detection purposes TCP Checksum is essential.
TCP cannot allow IP to checksum data however IP has its own checksum for its header. IP layer is basically responsible for routing of IP datagrams immaterial of whether that packet is intended for TCP services or UDP services. Thus immaterial of what information is contained in data part, IP layer is only responsible for routing of packets and all the issues related to error control, error detection, and flow control
Assignments
Submitted by:
Rahul Jwarchan
Stael Kitoto
Merveille Mokweme
Q.1 What are the main differences between OSI and TCP/IP reference models?
Explain briefly.
The main differences between the two models are as follows: -
- OSI is a reference model and TCP/IP is an implementation of OSI model.
- TCP/IP Protocols are considered to be standards around which the Internet has developed. The OSI model however is a “Generic, protocol-independent standard."
- TCP/IP combines the presentation and session layer issues into its application layer.
- TCP/IP combines the OSI data link and physical layers into the network access layer.
- TCP/IP appears to be a simpler model and this is mainly due to the fact that it has fewer layers.
- TCP/IP is considered to be a more credible model- this is mainly due to the fact because TCP/IP protocols are the standards around which the Internet was developed therefore it mainly gains creditability due to this reason. Where as in contrast networks are not usually built around the OSI model as it is merely used as a guidance tool.
- The OSI model consists of 7 architectural layers whereas the TCP/IP only has 4 layers
Q.2 Is TCP checksum necessary or could TCP allow IP to checksum the data?
- Yes, TCP Checksum is necessary.
TCP layer is responsible for error detection, error control, retransmission of packets if required, reassembly of packets as well as their fragmentation. Hence for all error control and detection purposes TCP Checksum is essential.
TCP cannot allow IP to checksum data however IP has its own checksum for its header. IP layer is basically responsible for routing of IP datagrams immaterial of whether that packet is intended for TCP services or UDP services. Thus immaterial of what information is contained in data part, IP layer is only responsible for routing of packets and all the issues related to error control, error detection, and flow control