Dear PSP PC colleagues, I have been in contact with Mr Roberto Laorden who is a member of the ICANN New TLDs Task Force (one of the 2 nominated by us) and he has sent me a statement drafted by the group for which the opinion of the PSO is required. I guess that it will be "officially" submitted to us by Stuart Lynn, but if you want to start looking at it, before our next teleconference, please find enclosed the text I have got from Mr Laorden: "The effect on DNS performance of adding new TLDs is still unknown. Conventional wisdom seems to be that although there are potential future risks in adding significant numbers of new TLDs, there may well be little or no risk Within the context of the DNS as used today, the scaling property of the system makes extensive use of cached information to avoid continual repetition of queries being directed towards higher levels of the DNS hierarchy. On the assumption that caching continues to be used extensively within existing and new TLD's, then the assertion regarding levels of risk associated with tens of hundreds of TLD's is, from a technical perspective, a relatively conservative assertion. On the other hand, there may be intended applications associated with new TLDs where caching of any information within the hierarchy of the new TLD may be counter to the intended behavior of the application. In such a situation the non-cacheable TLD may exert significant load pressures on the DNS system that may, in turn, affect the DNS's scaling properties. Given this possibility of non-cacheable name domains, this assertion regarding levels of risk is not highly conservative in nature and encompasses a reasonable estimate of bound of the scaling properties of the TLD domain. in adding tens or even hundreds of relatively small (in terms of numbers of domain names) provided they are not too "flat" in the shape of their hierarchy ? insofar as the distributed architecture of the DNS presumes a hierarchical namespace for effective performance. (Relatively large numbers of domain names at the second level ? as, for example, occurs with .com ? may jeopardize performance regardless of how few or how many top level domains have been authorized.) The PSO and the IETF should be asked for their views on whether this conventional wisdom is substantially correct." I suggest to add another point to the agenda of the teleconference in 7th December: - Analisys of NTLD Task Force statement Kind regards, Azucena ********************************************************* Azucena Hernandez Telefonica de Espaņa Desarrollo de Red Tel: +34 91 5846842 Fax: +34 91 5846843 GSM: +34 609425506 E-Mail: azucena.hernandezperez@telefonica.es ***********************************************************