IPv6 versus IPv4

Internet Protocol version 6 (IPv6), also known as the Internet Protocol next generation (IPng) is intended to sustain constant Internet growth with consideration of the number of users and functionality. The legacy IP version, IPv4, was implemented in the early 1980's based on stationary wired communication infrastructure. The IPv4 supports less than 2³² (over 4 billion) individual addresses, hence IPv4 suffers some limitations that may be inhibitors to growth of "tomorrow's" Internet, and use of the Internet as a global networking solution. Therefore, IPv6 is under development to take over IPv4's position by providing a greater expansion of IP address space; nonetheless, incorporating features of such include end-to-end security, mobile communications, Quality of Service (QoS), and system management burden reduction.

Without adequate global IP address space, applications have to work in such ways to afford local addressing. In a short-term, there have been various discretionary "workarounds" and extensions to IPv4 in and attempt to overcome its limitations. Network Address Translation (NAT) enables multiple devices to utilize local private addresses within an enterprise at the same time sharing one or more global IPv4 addresses for external communications. While NAT, to a certain degree, has postponed the exhaustion on IPv4 address space for the time being, it also complicates common application bi-directional communication. IPv6 simplifies the confusion of presenting an end-to-end security and eliminates the general incentive for using NAT since global addresses will be extensively accessible.

IPv4 had numerous issues, one of which was not having sufficient geographical distribution; it currently has less than 50% coverage throughout the USA. One the other hand, routing was too complex for new technologies and features such as mobile computing had coverage areas issues. Most significantly, the number of IP addresses is reaching its limit and the time has come to adopt IPv6 to compensate for the technical and address space requirements. Figure 1 shows IPv4 and IPv6 header formats.

Figure 1: IPv6 versus IPv4 header

 

Table 1 shows the differences in the IPv4 and IPv6 headers fields' differences. As shown, IPv6 offers a few additional fields compared to IPv4.

Table 1: IPv6/IPv4 header field differences 

IPv4 Header field	IPv6 Header field
ToS	Traffic class filed (QoS parameter)
Total length	Payload length
TTL	The Next header
N/A	Flow label (QoS parameter)
N/A	Next Header
The source address and destination addresses are based on 32-bits address fields	The source address and destination addresses are based on 128-bits address fields

INTRODUCTION TO IPV6 | Long Term Evolution (LTE)

IPv6 is, by far, one of the most important and significant technology and network upgrades in the communication history. This upgrade is growing slowly and will eventually terminate IPv4's network deployment at the end of the transition phase. IPv6 is designed to work with high speed network and low bandwidth networks, particularly suitable for wireless networks. The IPv6 design accommodates new technology requirements, such as QoS, security, and of course extended addressing.

Since the mid 90's many developers and researchers have been working on IPv6 and many RFCs are directly or indirectly discussing this technology. RFC 1883, released in 1995, is the first RFC in regards to IPv6. These efforts have been initiated and monitored by the Internet Engineering Task Force (IETF).

In the past several years IPv6 has deeply penetrated into the architecture of the Internet. Figure 1 (adapted from Gallaher & Rowe, 2005) presents a penetration estimates of IPv6 in the United States, which shows that by year 2010, almost 30% of ISPs and 18% of the users will be switching to IPv6.

Figure 1: IPv6 penetration in vendors, ISPs, and users

 

The main issue with IPv6 integration is its interoperability with IPv4. IPv4 is going to be around for at least a decade before all the networks are purely running over IPv6. Therefore it is essential to ensure IPv6 traffic flows are not going to have any negative impacts on IPv4 and vice versa. Dual-stack systems are considered a solution for the IPv6/IPv4 interoperability issue, which are going to be utilized in the design and implementation of systems for sustaining both IPv4 and IPv6 parallel processing to guarantee interoperability amongst the two protocol suites.

Mobility is another major features that is going to be impacted by this transition. 3G networks have been growing immensely in the past few years and IP connectivity has become an inseparable part of the 3G networks. The involvement of IP is going to increase more as 4G networks are becoming realizable. These requirements are being considered in the IPv6 applications.

This chapter will explore IPv6 features, in particular, in conjunction with LTE architecture. At first, IPv6 is going to be discussed and compared to IPv4. Following this introduction, IPv4-to-IPv6 transition, IPv6 security, Mobile-IPv6, and QoS-IPv6 are covered.