Authors Robert Blokzijl RIPE Chair Daniel Karrenberg RIPE NCC General Manager Background RIPE is an organisation founded in 1989 wich aims to ensure the technical and administrative coordination necessary for the operation of the Internet in Europe [ripe-01]. The RIPE NCC performs activities for the benefit of the Internet service providers (ISPs) in Europe and the surrounding areas; primarily activities that the ISPs need to organise as a group, although they may be competing with each other in other areas. In particular the RIPE NCC, as Regional Internet Registry, allocates and assigns IPv4 address space in Europe and surrounding areas [ripe-162]. The RIPE NCC started operations in 1992. It currently allocates address space to more than 800 local Internet Registries almost all of which are operated by ISPs. The number of local IRs is expected to reach 1250 in 1998. There are currently no indications that the number of local IRs will stop growing. The authors have contributed significantly to the development of the distributed Internet registry system which is used for the allocation and assignment of provider based IPv4 address space today. As such they have ample experience with the development of address space allocation and assignment policies. One important element of current policies is that the size of address space allocations is determined by previous justified use of address space. A prerequisite for this policy is that the size of allocations can start small and increase or decrease according to previous justified usage [ripe-159]. Argument We believe <draft-ietf-ipngwg-unicast-aggr-02.txt> is critically flawed because it standardises address aggregation boundaries without any explicit technical justification. In particular the length of the TLA and NLA fields are proposed to be standardised as fixed at prarticular values with no technical justification for either the fact that these lengths need to be fixed nor for the particular values chosen. The lack of technical justification is significant because the standardisation of TLA and NLA lengths directly influences many elements of Internet operations including address space allocation policies. In particular the TLA being fixed at 13bit length makes only 8K TLAs available per FP. Consequently Internet Registries will not be able to use proven allocation policies but rather engage in regulatory practises. The rules proposed in <draft-ietf-ipngwg-tla-assignment-01.txt> are clear evidence of this. Broad acceptance of such rules and their implementation is extremely unlikely unless there is convincing technical reasoning behind the constraints that necessitate the rules. Because of this critical flaw we request that the IESG not advance <draft-ietf-ipngwg-unicast-aggr-02.txt> and <draft-ietf-ipngwg-addr-arch-v2-05.txt> to proposed standard yet. We suggest that the IESG refer these documents back to the authors and the WG with the request to provide technical justification for the placement of aggregation boundaries and to consider making these boundaries variable where technically feasible. References The referenced RIPE documents can be accessed at http://www.ripe.net/docs/ripe-xxx.html HTML ftp://ftp.ripe.net/ripe/docs/ripe-xxx.txt ASCII ftp://ftp.ripe.net/ripe/docs/ripe-xxx.ps PostScript