IPv6 switch: ADSL needs overhaul

Since a significant part of SA's Internet market is dependent on Telkom's ADSL infrastructure, the country needs to move radically to replace it in time for the switch to IPv6.

So says William Stucke, a councillor at the Independent Communications Authority of SA, who notes that the old equipment used in parts of the ADSL network is not capable of being configured or upgraded to use IPv6.

On top of that, Stucke says, SA only has a single GSM network that is currently rolling out IPv6 connectivity. In that vein, this will render older cellphones, which do not have IPv6 capability, obsolete, although most PCs do, he notes.

“IP addresses are numbers used to uniquely identify devices on the Internet. IPv4 has 4 billion addresses, which are fast running out, and IPv6 has a number so large that we could number every atom in the universe.

“IANA provides IP addresses to Regional Internet Registries (RIRs), which provide them to Local Internet Registries (LIRs), which provide them to customers,” he says.

Reports have indicated that the Internet is facing turbulent times as RIRs, which allocate IP addresses to LIRs, many of which are ISPs, will run out of their pool of available addresses, at a date projected to be in late 2011 or early 2012.

However, Stucke says, while attention to the change to IPv6 is urgent, there is no doomsday scenario, provided interoperability between IPv4 and IPv6 is working well, and access networks still have sufficient IPv4 addresses available for growth in the immediate future.

software equivalent of 'flicking a switch', according to Stucke.

“The difficulty lies in the fact that a typical network contains many such devices, some of which are lacking the switch.

“Further, before one can consider 'flicking the switch', he must understand what exactly is involved. Understanding, planning, testing and more testing are required for a successful transition.”

He adds that the situation about addresses 'running out' is complicated by some LIRs handing back IPv4 addresses that they no longer require to the RIRs.

“It is also possible that some form of trading between LIRs or even end users in IP addresses may emerge. This may or may not be a good thing.”

However, Stucke explains that the RIRs running out does not mean that the LIRs have run out. “What it does mean, however, is that a new ISP won't be able to get any IPv4 addresses from the RIRs. Also, existing LIRs won't be able to get more IPv4 addresses.

“What will happen in a few years time is that customers of an existing ISP using only IPv4 may not be able to communicate with customers of a new ISP using only IPv6.

“The new ISP can't get IPv4 addresses and doesn't have any from before the exhaustion of the pool. So, if the existing ISP hasn't enabled IPv6 in his network, its customers won't be able to communicate with the new ISP,” he says.

Stucke adds that all existing ISPs and other network operators, such as telcos and MNOs will continue to have whatever has been allocated to them in the past.

“IPv6 enabled” or “IPv6 ready” doesn't mean that it will actually work. A little story: A couple of years ago, a well-known manufacturer supplied security cameras and a storage mechanism that were both 'IPv6 ready' to a university.

“Indeed, both devices could be addressed by IPv6, and the camera could be pointed in the right direction using IPv6. However, the cameras couldn't actually transmit their images using IPv6, nor could the storage device receive the images using IPv6. That part only worked using IPv4.”

Unlike the introduction of TCP/IP 28 years ago, says Stucke, there will be a gradual changeover from IPv4 to IPv6. “I would not be surprised if IPv4 is still in use 20 years from now.”

Nonetheless, he says the problems lie in two areas: “Network elements - including customer premises equipment - that can't handle IPv6; and interoperability between devices using IPv4 and IPv6.

“The problems have been significantly compounded by a 'chicken and egg' situation,” he notes, pointing out the questions: 'Why have servers and routers running IPv6 if no clients or customers are using IPv6; and, why use IPv6 if no services are available using IPv6?'.

According to Geoff Huston, chief scientist at APNIC, the RIR serving the Asia Pacific region, forecasts of IPv4 addresses running out in 2012 can not be confidently relied upon.

“Paradoxically, the closer we get to exhaustion, the less reliable this forecast becomes. Other models predict that IANA (which provides addresses to the RIRs) pool exhaustion will occur in the first quarter of 2011 rather than closer to the middle of the year.

“Why do these predictions disagree by as much as six months? Surely, as we get closer to exhaustion, the easier it is to predict the time when that last address block heads out the door,” Huston argues.

The difficulty in prediction is that there are many small allocations, and a few large allocations. The end date mostly depends on large allocations, he explains.

Stucke, however, points out local ISPs should prepare themselves for the inevitable switch. He urges the ISPs to acquire IPv6 addresses from AfriNIC (the African RIR), if they haven't done so already and to enable their networks to handle both IPv4 and IPv6 (dual stack).

He advises that the ISPs should also ensure that all routers, servers and services are also dual-stack; test and ensure that it all works, from IPv4 to IPv6, and visa-versa; peer with other ISPs using both IPv4 and IPv6 and allocate IPv6 addresses to new customers - which may involve choosing them carefully.

Stucke reckons that although the Beijing Olympics were run entirely on IPv6, the country with the highest IPv6 usage is the US.

“Currently, Europe has the highest IPv6 allocation rate. In Africa, South Africa has 31 allocations to 20 LIRs, followed by Kenya with eight, Mauritius with seven and Egypt with six. IPv6 allocations to 20 out of 274 SA LIRs with IPv4 allocations from AfriNIC isn't very many.”

AfriNIC is predicted to run out of IPv4 addresses in 2014, although the pace of allocations has increased significantly recently.

Related story:
IPv4: Four years left for Africa