Addressing the internet

With everything from mobile phones to vending machines becoming IP-enabled, the current IPv4 internet addressing scheme is exhausted. However, IPv6 offers a way forward

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By  Zoe Moleshead Published  December 29, 2002

IP address shortage|~||~||~|In parallel to the increasing proliferation of mobile devices in the worldwide market is the developing sophistication and internet orientation of these phones, PDAs and notebooks. While vendors, particularly mobile phone makers, are only too happy to fuel the increasing uptake of such devices with the launch of new web-enabled models every month, the internet has struggled to keep up with the added demand for new IP addresses.

This shortage is compounded by the fact that every device from servers, to routers and switches require an IP address. As a result, the four billion IP addresses provided by the existing Internet Protocol version 4 (IPv4) are running out and the Internet Engineering Task Force (IETF) has spent the last seven or eight years working on a protocol to overcome this — the result is IPv6.

“Very simply put IPv6 is a way to quadruple the existing internet address space. An existing IPv4 address is 32-bits long and IPv6 is 128-bits long. This was developed basically to mitigate the upcoming shortage of IP addresses,” says Stefan Olofsson, consulting engineer, Cisco Systems, Middle East.

“If you start estimating the number of addresses that can be allocated on the surface of the earth, then IPv6 can provide about 1000 addresses for every square metre of the earth,” comments Hein Vandermerwe, enterprise IT architect, Sun Microsystems, Europe, Middle East, Africa & Levant.

The IPv4 and IPv6 protocols define the addressing system of the internet and enable computers and other devices to communicate with one another through specified packet formats and addressing schemes. However, the standards defined by the IETF also govern a number of other factors, including interoperability. With the advent of IPv6, these standards will be hardened.

“All the standards for the internet are defined by IETF. Essentially what they have done is defined the components that go into the IPv6 architecture — this covers everything from the address space, routing protocols and the address assignment mechanism — so users can migrate from IPv4 to IPv6 infrastructure smoothly,” explains Olofsson.

With IPv6 development still ongoing, a temporary solution to the shortage of IP addresses arrived in the form of network address translation (NAT). Essentially, NAT has lengthened the lifecycle of IPv4 by enabling organisations to use the private IP address space, previously restricted for use with experimental networks, within their own corporate address space. This has reduced the strain on public IP addresses, as companies only require one connection to the public space rather than 100s or 1000s.

“With NAT, users can address their corporate network with this private address space and have a gateway that will connect the corporate network to the internet. The gateway will have a smaller range of public address space configured on it. For example, it could be 10:1 or 100:1 in terms of the number of nodes that would connect to the internet for the actual address space,” explains Olofsson.

However, NAT is limited as it does not actually expand the number of addresses available, instead it increases the efficiency of existing ones.

“NAT will just extend the life of IP for today, but when we start talking about other applications like 3G, which will require virtually every mobile phone to have an IP address, then IPv4 will not be sufficient,” comments Yarob Sakhnini, regional technical manger, Foundry Networks.

“The lifetime of IPv4 has been extended using techniques such as address reuse with translation and temporary-use allocations. Although these techniques appear to increase the address space and satisfy the traditional client/server set up, they fail to meet the requirements of the new applications. The need for always-on environments precludes IP address conversion, pooling, and temporary allocation techniques,” confirms Emad Makiya, general manager, Extreme Networks, Middle East & North Africa.

IPv6, however, will not just overcome the shortcomings in terms of IP addresses as the IETF and other IPv6 forums have been working to improve other aspects of IPv4, including the security and mobility of IP addresses.

While Olofsson says the security improvements are not dramatic, they will improve the embedded levels of security from IPv4.

||**||Enterprise migration|~||~||~|Additionally, IPv6 will enable devices to maintain a unique address whatever their location. Currently, devices such as mobile phones and PDAs can be assigned an IP address, but if users change countries their IP address also changes, making it impossible for other devices to locate and contact them.

“One current challenge with networking is that mobile addresses aren’t always connected to the network, or they can be connected in different places in the network, and if users have a mobile with an IP address they want it to be a unique device,” comments Vandermerwe.

“For example, mobile phone or PDA users don’t want to be known as Joe in Dubai but Jack in London because no other devices will be able to find them. That is one of the things that is strongly addressed in IPv6,” he adds.

Despite IPv6’s benefits, there are still some concerns about the performance degradation it may lead to. With IPv6 providing an address four times larger than IPv4, software and hardware performance may suffer and algorithms will have to be modified to handle bigger addresses.

“Typically, there will be performance degradation in software based platforms. In hardware based implementations performance degradation depends on how they have been implemented,” says Olofsson.

“The higher number of bits [128-bits for IPv6] the more processing power you require to crunch and forward IPv6 packets,” confirms Makiya.

However, he also explains that developments are being made to tackle this issue.
“Today, network processors (NP) are brought in to address such problems... Within two or three years we will see new ASICs designed specifically to provide IPv6… at wire-speed,” says Makiya.

The demand for IPv6 also varies from region to region and country to country, with Japan expected to lead IPv6 uptake as a result of mobile phone popularity. The scenario for the Middle East is not quite so pressing, and with vendors registering very little interest in the matter, its migration to IPv6 is likely to be at a slower pace than the Asia-Pacific region.

“IP addresses are not distributed evenly across the globe — some countries, even some institutions control the majority of IP addresses. The Asia/Pacific region is really starving for IP addresses and probably some countries in the Middle East — this is driving IPv6,” says Foundry’s Sakhnini.

While most vendors, including the likes of Sun, Microsoft and Cisco, have been working on IPv6 products since the mid 90s, they have only started releasing these products in the last couple of years. However, vendor advice for service providers and enterprises is to start planning ahead. Although there is no great urgency to migrate from IPv4, the fact that IPv6 will ultimately become standard means that some form of software or hardware upgrade is inevitable.

“From the enterprise perspective what they should do is set up a little lab and play around with IPv6 to get acquainted with it,” offers Cisco’s Olofsson.

“Service providers should really start planning ahead with IPv6. Whatever they buy today they need to be sure there is an IPv6 upgrade path and find out what needs to be done — is it forklift upgrade or a smooth easy upgrade?” comments Sakhnini.

Although the software side of IPv6 may not prove so challenging, enterprises do need to evaluate their IT infrastructure and outline a migration path for their servers, networking equipment and other IT kit.

“If a customer is running IPv4 on a CPU-based router then most probably they are not going to have to change the equipment — it will just be a software upgrade. If they are running IPv4 on hardware-based implementations — on ASICs — they are going to have to change the equipment. There has to be some transition period before a fully fledged IPv6 implementation,” explains Sakhnini.

Sun’s Vandermerwe says that IPv4 is not expected to be exhausted until 2007, and as such enterprises and service providers are not under any immediate pressure to overhaul their IT infrastructure. “It is not a big bang approach, it’s a slow migration towards IPv6,” adds Vandermerwe.||**||

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