Actually you can still use ENUM even before gets widely deployed (read: properly delegated). As long as your SIP server and gateways are configured to use the DNS servers serving your E164 zone it does not matter if the zone is not delegated or your number prefix is not yours. Shortly said the users of each proxy can benefit of ENUM lookups except if the queries are meant for outside zone. I can for instance use SER to automatically dial the ENUM entry of one user and if it fails to use the PSTN gateway. Dialing +31-23-5458104 SER will first try the SIP address ag(a)ag-projects.com and if ag is not online will fall back to PSTN. Adrian Georgescu ag(a)ag-projects.com http://ag-projects.com Tel: +31-23-5458104 IP phone: sip:ag@ag-projects.com ------------------------------------------------ DNS, ENUM & IP telephony http://managed-dns.org/ On (10.11.03 16:42), Alessio Focardi wrote: the format of phone numbers. So, an E.164 number is simply a phone number. If you're talking about ENUM entries: You would need to have phone numbers for your users plus a ENUM DNS infrastructure in your country. If you have already a phone number, you could give your users extensions behind that number. Unfortunately, there is no ENUM trial going on in Italy yet, so you won't be able to publish ENUM records for your users in the public DNS in that case, so other users would not be able to find your users via ENUM. But, you could still use ENUM for finding other ENUM users, a currently small, but rapidly growing community. You won't need to keep a "prefix to domain" list for all the other VoIP providers, and your users won't have to remember "which prefix to dial for which provider?" to see a rough sketch how it works, take a look at our presentation at http://enum.nic.at/documents/AETP/Presentations/Austria/0017-2003- 07_ENUM-Demo_ietf57.ppt I'm happy to supply you with more detail in private mail, i consider that being already quite off topic on the SER users list. Feel free to contact me. cheers axelm