This is the fourth story in our series, investigating how number resource policies changed the development and growth of Internet infrastructure in the APNIC region.
A core goal of address policy is aggregation: distributing IP addresses in a hierarchical way to avoid fragmentation of address blocks and to limit the growth of Internet routing tables. The intent of this is to ensure that gateway routers, which carry a ‘default free’ BGP routing table, are able to manage Internet routing efficiently in real-time.
However, the goal of aggregation must be balanced with the desire for more provider-independent address space by smaller network operators, who are otherwise constrained by the use of space from their upstreams. This balance has shifted over time, with the ‘minimum allocation’ of IPv4 address space being gradually reduced, in order to provide access to IP addresses to more and more smaller networks.
In 1996, APNIC’s minimum allocation was /19, and this was reduced twice before mid-2008 when APNIC’s minimum IPv4 allocation was a /21 address block, or 2,048 IPv4 addresses. To receive this space, a network operator had to demonstrate to APNIC that they had properly used at least a /23, or 512 IPv4 addresses, received from their upstream service provider.
|Date||Old size||New size|
|04 August 2000||/19||/20|
|16 August 2004||/20||/21|
|04 August 2008||/21||/22|
|09 May 2011||/22||/24|
Table 1 – History of APNIC minimum IPv4 delegation size changes.
At this time, the Internet was growing rapidly, and many new, small ISPs were entering the market. However, it was difficult for many of them to satisfy the APNIC requirement to show the use of 512 addresses. In many cases, those ISPs could obtain a /24 (256 addresses) from their upstream, but no more than that.
Rajesh Chharia, President of Internet Service Providers Association of India (ISPAI) and CEO of Indian ISP CJ Online, recognized how the /21-minimum policy was limiting network operators in India and other developing economies, and that the advancements in routing technology could allow a further reduction of the minimum allocation, to a /22.
“Talking to the Internet community in India, through ISPAI and having attended and been involved in APNIC Policy SIG discussions, I became aware of the challenges people working in the industry in India and other emerging Internet economies faced,” says Rajesh.
“There are a lot of smaller ISPs and technology-driven businesses who do not actually require a /21. After many discussions with my colleagues in India and around the region, I understood these organizations would be satisfied with a smaller minimum allocation.
“My initial proposal was to reduce the requirement for receiving address space from APNIC: to reduce the minimum allocation to a /24 (256 addresses).”
The benefits of smaller minimum allocations
The policy (prop-053) was designed to allow more ISPs to qualify for addresses directly from APNIC and to more easily enter the Internet market in India and elsewhere.
Allowing smaller ISPs to request an allocation smaller than a /21 would make obtaining a direct allocation from APNIC more affordable, while at the same time maintaining a level of frugality with the remaining IPv4 address pool.
“This is good for competition and development in India and other developing economies as it lowers a barrier to entry,” Rajesh says.
The PDP in action
The first version of the policy was discussed on the Policy mailing list and the minimum allocation of a /24 became a sticking point, with the community debating the possible disadvantages:
- Will the /24 be too small to be routed?
- Is /24 really enough for even a small ISP?
- Will this de-aggregate the IPv4 address space too much?
- If we do this, will it blow out the size of the routing table faster than technology can keep up?
With this community feedback in mind, Rajesh revised the proposed minimum allocation to a /22 and took this to the APNIC Policy SIG meeting at APNIC 25, Taipei in February 2008.
“There were three challenges we needed to overcome to gain consensus,” explains Rajesh.
“First, it was important to describe the situation and the challenges and convince the APNIC policy community this was a genuine problem, not just for me or my economy, but also for others. Of course, many people understood this, but not everyone,” he says.
“Second, I had to show that my proposed policy change would help the situation, by ensuring new and small networks were not ‘locked out’ of the ISP industry.
“Third, I had to look very carefully at the possible disadvantages of my proposal and be sure that they were properly understood and managed. I knew that the ‘minimum allocation’ policy was designed to limit the number of independent allocations which were made and control the growth of the Internet routing table. So, I had to convince the community that the impact of the policy change would be acceptable.”
The policy reached consensus at the meeting and was implemented by the Secretariat in August 2008.
Rajesh’s tips for becoming involved in the policy process
- It’s important to understand APNIC policies. This is easier for network operators and engineers who are affected by the policies, who always need to follow policies; but it is also very important to understand the reasons for the policies and the impact of changes.
- You need to understand the community, to be known and trusted as a knowledgeable and genuine participant in the process. This can come only from attending policy meetings and participating in the discussions.
- Finally, it is necessary to have patience. I have seen some policy proposals agreed quickly by the community and others that had to be modified and presented again, two or three times. But if a proposal is sensible and if concerns are addressed, most proposals are successful eventually.
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