ENUM Lookup

http://enumquery.com/

http://www.enum.org/

http://www.sipbroker.com/sipbroker/action/enumLookup

http://www.google.com/search?tab=sw&sa=N&hl=en&lr=&q=ENUM+lookup

hope to find out some tips for development 

http://www.e164.org/wiki/StuffThatSupportsENUM

https://support.pillwax.com/open-source/doku.php?id=linux:asterisk

http://www.cs.columbia.edu/sip/servers.html