IPv6 is good for IoT and IoT is good for IPv6. There are several arguments and features that demonstrate that IPv6 is actually a key communication enabler for the future Internet of Things.
With an ever expanding user base and a growing number of IP-enabled devices, there are serious concerns about IPv4 limited feature set as well as robustness not to mention the all important factor, scalability.
The Internet Protocol Version - IPv6 - is being developed as a critical technology meant to address all those concerns. It is expected to not only provide better services for existing technologies and applications but also meet growing demands of new IP-based devices and services. So let's find out why IPv6 is better than IPv4, examining all its features.
#1 - Larger IP address space
IPv4 uses 32 bits for an IP address that allows about 4 billion unique IP addresses. When IPv4 was introduced in the 1970s, it was therefore firmly believed that these 4 billion addresses would be sufficient to cover any future growth of the Internet.
IPv6 uses 128 bits for IPv6 addresses which allows for 340 billion billion billion billion (3.4x1038) unique addresses.
To get an idea of the scale involved, consider the entire IPv4 space as being contained in an iPod, then the new IPv6 space would be the size of the Earth. From these numbers, it can be seen that with IPv6, it is possible to provide billions of addresses to each person and ensure that any device that has to be connected to the Internet will have a unique IP address.
The first advantage of an enhanced address space is that in the absence of NAT, there is less complexity in the network hardware and software, and configuring a network becomes much simpler. Secondly, it makes it possible to truly envisage a networked home wherein the different gadgets and appliances would be on the network which would require that each such device have a unique IP address. Finally, the large availability of IP addresses removes any obstacles that existed previously in the full deployment of wireless and mobile devices.
#2 - Better end-to-end connectivity
As mentioned earlier, the shortage of addresses caused by IPv4 has been overcome to some extent by using NAT, which basically translates one unique global address to multiple private addresses. In the absence of unique IP addresses for each end, NAT creates difficulty in ensuring proper end-to-end services. The present solution is for the application developer to engineer special NAT traversal techniques or to have additional servers to simulate peer-to-peer communication.
IPv6 with its large address space no longer requires NAT and can ensure true end-to-end connectivity. This means peer-to-peer applications like VoIP or streaming media can work very effectively and efficiently with IPv6.
#3 - Autoconfiguring devices
With even more computers and devices using IP, there was need for an IP protocol that would ensure easy and automatic configuration of devices and routers. Further, new devices that are using IP now are getting simpler and may be used in environments where particular server dependencies may not be acceptable.
IPv6 offers automatic configuration and more importantly, simple configuration mechanisms. Known as plug-and-play autoconfiguration, these capabilities are way beyond what IPv4 currently offers. IPv6 offers DHCPv6, which is an autoconfiguration similar to IPv4 DHCP and offers stateful address autoconfiguration.
In addition, IPv6 also offers stateless or serverless address autoconfiguration. In stateless autoconfiguration, a host can automatically configure its own IPv6 address and does not need any assistance from a stateful address server. Entire IPv6 prefixes rather than just an address are delivered to a device. This particular feature enables routers to easily autoconfigure their interfaces and can be used very effectively in broadband access networks to dynamically provide customer gateways.
#4 - Simplified Header Structures and faster routing
The IPv4 header has two main problems that are instrumental in slowing down throughput - each packet must be processed and checksum computed, and each router that processes a packet must process the option field. This can cause a gradual degradation in performance during the forwarding of the IPv4 packets.
When compared to IPv4, IPv6 has a much simpler packet header structure, which is essentially designed to minimize the time and efforts that go in to header processing. This has been achieved by moving the optional fields as well as the nonessential fields to the extension headers that are placed only after the IPv6 header. Consequently, the IPv6 headers are processed more efficiently at the intermediate routers without having to parse through headers or recompute network-layer checksums or even fragment and reassemble packets. This efficiency allows for reduced processing overhead for routers, making hardware less complex and allowing for packets to be processed much faster.
Furthermore the extension header allows for more flexible protocol inclusions than what IPv4 does. In contrast, IPv6 extension headers have no such restriction on the maximum size. They can be expanded to accommodate whatever extension data is thought necessary for efficient IPv6 communication. In fact, a typical IPv6 packet contains no extension header and only if intermediate routers or the destination require some special handling, will the host sending the packets add one or more extension headers depending on the requirement. This new extension header makes IPv6 fully equipped to support any future need or capabilities.
#5 - Better security for applications and networks
The Internet has functioned for the last three decades with IPv4 as the underlying protocol. However, because of this end-to-end model, IPv4 was designed with almost no security in mind and assumes that the required security will be provided at the end nodes.
Network Address Translation (NAT) and Network Address Port Translation (NAPT) were used to provide some level of protection against some of the threats using methods such as firewalls. Also the introduction of the IPSec protocol, allowed some communication to be encrypted but its implementation in IPv4 is optional and the whole responsibility of ensuring secure communication still lies with the end nodes.
In IPv6, IPSec is a major protocol requirement and is one of the factors in ensuring that IPv6 provides better security than IPv4.
IPSec contains a set of cryptographic protocols for ensuring secure data communication and key exchange.
The main protocols used are:
1. Authentication Header (AH) protocol, which enables authentication and integrity of data.
2. Encapsulating Security Payload (ESP) protocol, which enables both authentication and integrity of data as well as privacy of data.
3. Internet Key Exchange (IKE) protocol. This protocol suite helps to initially set up and negotiate the security parameters between two end points. It then also keeps track of this information so that the communication stays secure till the end.
Thus, IPv6 ensures that there are end-to-end security mechanisms that will provide authentication and encryption abilities to all applications and thereby eliminates the need for applications themselves to have integrated support for such abilities. The added benefit of using the same security mechanisms for all applications is that setting up and administering security policies becomes a lot simpler. IPv6 allows for complete end-to-end security thereby allowing for a new set of personalized services to be deployed such as mobile e-commerce services that rely on secure transactions.
#6 - Better Quality of Service (QoS)
In IPv4, the Type of Service field or the Differentiated Services Code Point field in the packet header, has a very specific task of classifying the packet and defining what kind of service is expected by the packet, while being delivered through routers across the network. This is typically done through devices in the network, which will classify the packets based on the needs of the particular application. However, this also means that not all QoS-compliant devices are compatible with one another.
QoS is given a special boost in the IPv6 protocol with the IPv6 header containing a new field, called Flow Label field that defines how particular packets are identified and handled by the routers.
The Flow Label field allows packets that belong to a particular flow, in other words, that start from a particular host and head to a particular destination, to be identified and handled quickly and efficiently by the routers.
The Flow Label Field thus ensures that there is more efficient delivery of information from one end to another without the possibility of it being modified by intermediate systems. This ensures a high degree of QoS especially for peer-to-peer applications and other real-time applications.
#7 - Better Multicast and Anycast abilities
The biggest problem with IPv4 multicast is that it is possible only on subnets and most Internet routers are not configured to support IPv4 multicast. For effective use of multimedia applications it should be possible to address different hosts, which belong in different subnets.
IPv6 extends the multicasting capabilities of IPv4 by offering a large multicast address range. Obviously, this limits the degree to which the information packets have now to be propagated and significantly improves the network efficiency.
IPv6 also improves dramatically on the concept of anycast services, which is available, though in a very minimal form in IPv4. In anycast services, packets are not sent to all the nodes in the network but only to the nearest reachable member.
#8 - Better mobility features
When we consider IP mobility features we are essentially considering features that would be useful for:
- Mobile devices, which can change their location but would like to retain existing connections.
- Mobile networks that provide mobility to a group of devices
- Ad-hoc networking in which some of the devices stay connected to the network or in the vicinity of the network only for the short duration of a communications session.
Mobile IPv4 requires a special router in the location of the mobile node to properly receive calls. Also, route optimization is available to mobile IPv4 only through an optional set of extensions. There is also an ingress filtering problem in mobile IPv4 since the correspondent node uses the home address as the source address of the packet and there may be confusion on which IP addresses it should be allowed to accept or not.
With IPv6, mobility support is mandatory by the use of Mobile IPv6 (MIPv6). Route optimization is a built-in feature for mobile IPv6. Further, features like Neighbor Discovery and Address Auto-configuration allow mobile nodes to function in any location without needing the services of any special router.
MIPv6 can be used to achieve seamless mobility by allowing handovers between different access technologies say from example from a cellular network to a wireless network, with minimum interruption to ongoing connections. There is no ingress-filtering problem in Mobile IPv6 because the correspondent node uses the care-of address as the source address.
These devices increasingly demand delivery of converged voice, video and data, which is made possible through a standard called the IP Multimedia Subsystem (IMS) standard. However IMS requires that each mobile device have a unique IP address, which is a persistent IP address in order to ensure full bi-directional services.
IPv6 through its large address space ensures that each mobile device can have its own unique IP address.
#9 - Ease of administration
When an existing network is to be expanded or two networks to be merged, or when service providers are changed, a network needs to be renumbered, as a new address scheme will be assigned to it. With an IPv4 network, all the work of network renumbering and assigning of new address schemes would have had to be done manually.
IPv6 provides capabilities so that network renumbering can happen automatically. Thus, network renumbering with IPv6 will no longer requires manual reconfiguration of each host and router and makes for smoother switchovers or mergers.
Another useful administrative feature of IPv6 is its multihoming technique. In this simultaneous connections are established to two ISPS. When service to one ISP is lost, there is a back-up connection to the Internet. This ensures far greater reliability of services, as there is more than one path from the host to the destination.
#10 - From IPv4 to IPv6: a smooth transition
IPv4 has been successfully deployed the world over for many years now and its popularity is a testament to the success of its design.
IPv6 follows many of the same design features that made IPv4 so successful. This makes it possible to have a smooth transition from IPv4 to IPv6.
There are many commercially attractive applications in the market today that require IPv6 and may tempt many to go in for a rapid transition to IPv6. A successful IPv4 to IPv6 transition mechanism is one in which IPv6 elements are incorporated into the network while at the same time compatibility is maintained with the pre-existing, large base of IPv4 hosts and routers. Thus, for some time to come, IPv6 hosts and routers must interact and function with the existing IPv4 network infrastructure. A number of such transition mechanisms have been defined that allow for the two networks to co-exist till such a time that a complete