The Next Generation IP

The Next Generation IP

Recent years saw huge increase in Internet growth there were 40,073 networks on Internet (as of 10/4/94) and it was doubling approximately every 12 months. The current version (IPv4) of Internet Protocol was sufficient for 20 years, but if Internet will continue to grow, pretty soon we will run out of addresses for all connections because IPv4 can handle only 32 bit addresses (which are millions of connections). This is the major drawback of IPv4. The other issues is that IPv4 was not designed to handle real time applications such as video and audio efficiently and IPv4 can create a lot of fragmentation due to the lack of ability to predict or detect the bottlenecks in the packet’s path.
The next generation of IP was designed by Internet Engineering Task Force (IETF) to handle all of these problems and was first presented on July 25, 1994 in Toronto. Thou structurally it is very different from IPv4; it still incorporates all the successful features of IPv4 like its ability to adapt to many topologies or technologies at the same time. IPv6 is also connectionless and routed independently. The biggest problem was solved by increasing address format from 32 bits to 128 bits. This increase gave 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses (should be more that enough for a long time). IPv6 is also better designed for choosing the optimum path of the packet since switching the paths for each packet will degrade performance of the network. You (well the protocol) can request the unbreakable path, for the applications that need constant connection, through the same route. You need this feature to successfully transmit high quality video and audio over the net. Another great advantage of IPv6 is its compatibility with the IPv4. This will make transition between these two versions painless. Because it doesn't matter how well a new protocol is if there is no practical way to transition the current operational systems running IPv4 to the new protocol.
Structurally both versions are also different. They have different datagram systems and unlike IPv4, IPv6 does not specify all the possible protocol features, this makes it more adaptable to the user’s needs. The datagram in IPv6 consists of Base Header, Optional Extension Headers, and the Data Area. The Base Header is twice as large than in IPv4 due to the added extra 96 bits to the each destination and source addresses, but it actually contains less data. It contains: VERS – for version IPv6, PRIORITY – specifies the urgency
0 Uncharacterized traffic
1 "Filler" traffic (e.g., Netnews)
2 Unattended data transfer (e.g., email)
3 (Reserved)
4 Attended bulk transfer (e.g., FTP, HTTP, NFS)
5 (Reserved)
6 Interactive traffic (e.g., telnet, X)
7 Internet control traffic (e.g., routing protocols, SNMP),
FLOW LABEL – designed for use with performance dependant applications, PAYLOAD LENGTH –how much data is in the packet, NEXT HEADER – tells what is the data going to be in the next header, HOP LIMIT – same as time to live, and SOURCE and DESTINATION addresses. The Base Header takes 40 octets without the optional headers. The IPv6 also differs in the way it is assigning addresses. It has 3 different types: unicast, multicast and anycast. UNICAST (uni – one) address corresponds to the single machine and datagram is given a shortest possible path. MULTICAST corresponds to the many computers on the Internet. It basically sends a copy of the packet to each node. The set of nodes is dynamic they can change over time. ANYCAST sends one copy of a datagram to the group of PCs that share same class prefix (same network). IPv6 also saves space by using ‘0’ address compression which works by compressing many 0’s in one row into smaller equivalent.
The other advantage of IPv6 over IPv4 is the better data security. This is achieved by adding two optional extensions “Authentication Header” provide authentication and integrity to IPv6 datagrams. The second security extension header provided with IPng is the "IPng Encapsulating Security Header" this mechanism provides integrity and confidentiality to IPv6 datagrams. Both extension headers are flexible and algorithm independent, this provides flexibility and universality to them.