Introduction
The Internet Protocol (IP) is the official protocol for internet communication. It ensures better handling of the communication structures and layered approach. The IP4 is presently the official standard as IP6 has resulted in next generation of internet protocol which offers better security and less errors. The comparison and similarities would assist us in fostering better insight into the protocols with deep explanations.
The first section highlights the IP4 and IP6 versions and ensures a good insight on the protocols with relation to their communication and transmission patterns.
The second section ensures comparison of the protocols which stands crucial for the development of the network society and ensures a better approach for security and communication.
IP4 and IP6
The IP4 has two level address structures which represent the network id and the host id further categorized in five classes A through E. In any case if an organization is offered a class C address domain, it barely gets 256 addresses and that stands quite inefficient for the large domain of users. It stands quite inefficient in the use of the address space. Several millions of address is wasted in classes D and E. Although some sub-netting and super netting has resolved some of the problems, routing becomes quite complicated in such circumstances.
The feature of minimum delay strategies and maximum reservation of resources are some of the crucial traits which IP6 brings forth and capitalizes over the feature of IP4. Only then it would accommodate large real-time video and audio transmission (Bradner, 2003, p 45-46).
Another essential feature is the encryption and authentication which has already become a large issue in internet communication and IP4 is not able to provide that over which IP6 takes a lead.
IP6 over IP4:
The advantages of IP6 over IP 4 are as follows:
1. Larger address space: An IPv6 address is 128 bits long in comparison to the 32 bit address space which is precisely 2 to the power 96 increase in the address space (Huston, 2005).
2. Better header format: IPv6 enforces the use of a better header format in which options are separated from the base header and inserted as required by the protocol. The insertion of the options between the header and the upper data layer. This simplifies and fastens up the routing process as most of the options are not checked by the routers (Bradner, 2004, p 47-49).
3. Allowance for extension: IPv6 is designed to allow the extension of the protocol if required by the new technologies or applications.
4. Support for resource allocation: The IPv6 allows flow label to enable the source to request special handling of the data packets which supports real-time audio and video.
5. Better security in internet communication: The features like encryption and authentication options in IPv6 ensure better security aspects to be strengthened thus providing more confidentiality and integrity of the packet.
Addressing format:
IPv4 user binary notation for representation of its address space which is contained in 4 octets each containing 8 bytes each. In comparison IPv6 uses hexadecimal colon notation. This format has encouraged bigger address format to store and allocate large number of address.
Figure 1: Abbreviated address
Abbreviation:
In IPv6 the leading zeros can be omitted which ensures better spacing of the addresses of the protocol and IPv4 in contrast reduces its address space because of the reason (IETF, 2005).
Figure 2: Abbreviated address with consecutive zeros
The IPv6 in comparison to IPv4 also provides the following:
Figure 3: Address Space
The IPv6 ensures that the address space is enlarged enough to accommodate large spaces for the internet domain than the existing IPv4. It also enforces better security and handling mechanism.
Figure 4: Provider-based address
The provider based address is used by the normal host as an uncast address.
Figure 5: Address hierarchy
The specifics are as follows:
· Provider identifier: This variable length field identifies the provider for internet address and usually recommends 16 bit length.
· Subscriber identifier: This address is assigned when the enterprise applies to the internet. It is usually of 24 bit.
· Subnet identifier: Each enterprise can have several subnets and such information is stored into it.
· Node identifier: The length chosen is 48 bits which ensured better handling the nodes of the organization.
The following shows the IPv6 datagram packets and its structure:
Figure 6:IPv6 datagram
Transition from IPv4 to IPv6:
Figure 11: Three transition strategies
The comparison can be further high lightened as follows:
1. The header length field is eliminated in IPv6 as it is constant for this version (Forouzan, 2003, p 801).
2. The service type field is absent in IPv6. The priority and flow label fields together take over the function of the service type field.
3. The total length field is not present in IPv6 which is replaced by the payload length field.
4. The identification, flag and offset fields are eliminated from the base header in IPv6 and are included in the fragmentation extension header (Forouzan, 2003, p 801).
5. The TTL field is called hop limit in IPv6.
6. The protocol field is renamed as the next header field.
7. The header checksum is got rid of as it is there in the upper layer protocols and thus is of no need. It also eliminates the extra overhead for communication.
8. The selection fields in IPv4 are done as addition headers in IPv6.
Figure 12: Dual stack
The similarity is quite clear from the diagram, only the network level is changed in the two version of the protocol (Forouzan, 2003, p 815-817).
Figure 13: Automatic tunneling
The difference is evident in that the header and the payload information are handled.
Figure 14: Configured tunneling
The configured tunneling is one of the primary difference creators in the communication layers.
Figure 15: Header translation
The header translation is quite swift in IPv6 than IPv4.
Conclusion
IPv6 is not yet widely used in spite of its added advantages win comparison to IPv4. The reasons are many from economy to data communication style. Yet IPv6 stands out in terms of security and large pattern of communication.
References/Bibliography
C. Huitema (2002). IPv6: The New Internet Protocol, Upper Saddle river, NJ: Prentice Hall.
E. Britton, J. Tavs and R. Bournas (2003). “TCP/IP: The Next Generation”. IBM Sys. No. 3.
Forouzan, A. Behrouz (2003). TCP/IP Protocol Suite, second edition. Tata McGraw Hill, pp 810-813.
Huston, Geoff (2005). “Just how big is IPv6? – or where did all those addresses go?”. Retrieved 20, February 2009 from http://www.potaroo.net/papers/isoc/2005-07/ipv6size.html.
IETF (2005). “IPv6 Rationale and Features”. Retrieved 20, February 2009 from http://www.ipv6book.ca/doc/ipv6book-chap1.pdf.
S. Bradner and A. Mankin (2004). IPng: Internet Protocol Next Generation, Reading MA: Addison-Wesley. Retrieved 20, February 2009 from http://docs.hp.com/en/AB286-90002/AB286-90002.pdf.
