VoIP Cookbook: Delegation Concept in ENUM
We hope as we are ready each country will have their very own ENUM Server and receive a delegation from e164.arpa. For Indonesia, it would be 2.6.e164.arpa for handling country code (+62).
To understand how ENUM works, one needs to understand how a Domain Name System (DNS) works as ENUM uses DNS Server. Thus, ENUM works fairly similar to DNS but to map and to delegate a phone number. Please note that ENUM is different from a SIP Server.
Imagine at national level there is an allocation of area code for SIP network on +62555. It can be mapped to ENUM under the domain, for example, 188.8.131.52.6.e164.id. It may have several ENUM Name Server (NS) such as,
ENUM Server Domain 184.108.40.206.6.e164.id +62555 ENUM NS 220.127.116.11 +62555 ENUM NS 18.104.22.168
Please note that at national level, the ENUM Server may not have a complete information on the subscribers.
For example, a community or a corporate or a telecomunication operator, assigned 4444 area code for its network, such that, it may use
+6255544440000 - +6255544449999
basically, it may allocate phone number for 10.000 subscribers. Thus, the community may run their own ENUM server under the sub-domain 22.214.171.124.126.96.36.199.6.e164.id, for example
ENUM Server Domain 188.8.131.52.184.108.40.206.6.e164.id +62555444 ENUM NS 220.127.116.11 +62555444 ENUM NS 18.104.22.168
In the delegation process, the NS information of ENUM 22.214.171.124.126.96.36.199.6.e164.id must be written in ENUM 188.8.131.52.6.e164.id that tells
184.108.40.206.220.127.116.11.6.e164.id IN NS 18.104.22.168 22.214.171.124.126.96.36.199.6.e164.id IN NS 188.8.131.52
ENUM concept is not confined to operator, any corporate or community with smaller number of extensions, e.g., 100 extentions may use, for example, ENUM allocation for,
+6255566666600 - +6255566666699
Thus, this particular corporate must has its own ENUM server or collocate to other ENUM server to handle 184.108.40.206.220.127.116.11.5.2.6.e164.id, such as
NUM Server Domain 18.104.22.168.22.214.171.124.5.2.6.e164.id 62555666666 ENUM NS 126.96.36.199 62555666666 ENUM NS 188.8.131.52
Delegation process for NS of 184.108.40.206.220.127.116.11.5.2.6.e164.id must be entered into the main ENUM Server for 18.104.22.168.6.e164.id tto tell
22.214.171.124.126.96.36.199.5.2.6.e164.id IN NS 188.8.131.52 184.108.40.206.220.127.116.11.5.2.6.e164.id IN NS 18.104.22.168
The ENUM delegation concept is clearly shown that is not limited to operator. Any entities may have their very own phone number. Thus, a more comprehensive authentication process may be needed to make sure the phone number is properly delegated.