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ENUM-based Softswitch Requirement <draft-lim-kim-enum-based-softswitch-00.txt> 6 Nov. 2006 67th IETF - San Diego, USA JoonHyung Lim, Weon Kim National Internet Development Agency of Korea (NIDA, former KRNIC) Before beginning… • Since 2005, NIDA has been operating “2.8.e164.arpa” zone. • Recently, two Korean VoIP carriers and NIDA are testing call routing using Infrastructure ENUM. • To setup a call through the ENUM DNS, ENUM modules embedded on softswitches of carriers make appropriate queries defined on RFC3761. What we made is… *Extensible Provisioning Protocol (EPP) Provisioning numbers with EPP ENUM (Only contains numbers of 2 carriers now) Provisioning numbers with EPP Request NAPTR RR SIP URI Softswitch B Softswitch A Carrier A IP Phone A Call routing Carrier B IP Phone B Motivation • At the beginning, Infrastructure ENUM DNS does not have all numbers of carriers in the world. • What if a softswitch cannot get a routing information from Infrastructure ENUM DNS? • Is there any consideration about softswitch when it tries to use ENUM? Objectives • Allow softswitch can route every call comes in even if it does not get the routing information from Infrastructure ENUM. Method • Step 1 : – Softswitch MUST look up a call routing information (i.e. SIP URI) from Infrastructure ENUM DNS. • Step 2 : – If a softswitch gets call routing information from Infrastructure ENUM DNS, softswitch uses it. – If it does not get an call routing information (Rcode=3), softswitch looks it up on database of softswitch itself again. • i.e. Usually, softswitch may have a feature for call routing based on prefix of a number as a legacy telephone switching. Example • Example 1 – ‘Subscriber A' makes a call to “+82-70-7800-1234” – ENUM-enabled Softswitch A transforms the number to “4.3.2.1.0.0.8.7.0.7.2.8.e164.arpa” and then query to Infra ENUM DNS. – 07078001234@carrier_a.co.kr (SIP URI) returned. • Example 2 – ‘Subscriber A’ makes a call to “+82-70-7800-1234” – ENUM-enabled Softswitch A transforms the number to “4.3.2.1.0.0.8.7.0.7.2.8.e164.arpa” and then query to DNS. – Nothing returned. – Softswich recognizes the prefix of number “070-78??” is owned by “carrier_a.co.kr” Next step • More discussion on WG mailing list.