12/18/2000 enum administration penn pfautz at&t 732-420-4962 [email protected]
TRANSCRIPT
12/18/2000
ENUM Administration• Mixes domain registration and telephone number
administration– Rights to ENUM domain tied to corresponding number
assignment in the PSTN– Rights to number in ENUM lost when service on
number is disconnected– Generally, telephone service provider is only party that
knows about number assignments & disconnects– Design issue for industry & regulators: How to balance
need for TSP involvement with burden on TSP and a competitive environment?
12/18/2000
e164.arpa (RIPE-NCC)
nsnanp_enum.com(1.e164.arpa)
4.6.e164.arpaSweden
...
$ORIGIN 3.7.9.1.e164.arpa. 7.8.7.6.6.3.2 IN NS e164.att.net.8.8.7.6.6.3.2 IN NS joes-enum.com
e164.att.net $ORIGIN 7.8.7.6.6.3.2.3.7.9.1.e164.arpa. IN NAPTR 10 10 "u" "sip+E2U" "!^.*$!sip:[email protected]!" . IN NAPTR 102 10 "u" "mailto+E2U" "!^.*$!mailto:[email protected]!" . IN NAPTR 102 10 "u" "tel+E2U" "!^.*$!tel:+19732366787!" .
$ORIGIN e164.arpa.1 IN NS nsnanp_enum.com4.6 IN NS sweden_enum.com .
Tier 1 – Registry- defined by ITU member state
Tier 2 – Service Registrar
ENUM Hierarchy
sip.att.com
Tier 3 – Application Service Provider
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e164.arpa
• .arpa TLD since infrastructure
• RIPE NCC will host
• Essentially populated with identities of name servers for country codes
• ITU indicates to RIPE authority for each country code
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Tier 1 (Registry) • Entries point to Service Registrar for a number• Provider(s) determined by national authorities
– NANP-wide or per NANP nation?
• Because of number portability, Tier 1 name server must point to Service Registrar on an individual number basis; numbers can’t simply be delegated to the carrier to which their Central Office code or thousands block was initially assigned
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Tier 2 (Service Registrar)
• Hosts NAPTR (service) records for a telephone number
• All records for a given number must be in one name server
• Major issue is who can be Service Registrar– Two “strawman” models presented to IETF
• Any properly accredited domain name registrar (model I)
• Telephone service provider (model II)
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Reference Model I (General)
T1E
T2E End User
TSP ASP
A
BC
F G
ED
New T2E
H
LegendASP Application Service ProviderTIE Tier 1 Entity (Registry)T2E Tier 2 Entity (Registrar)TSP Telephony Service Provider
** End User can be the end user itself or an agent authorized to represent the end user.** TSP can offer application services also. The “TSP” entity performs functions specific to the TSP.
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Reference Model I – Pros & Cons Pros:
• EU determines T2E, EU has more control• EU can be T2E (e.g., universities and enterprises)
for his/her own TN(s)• Enable competitive T2E service offering
Cons: • More complicated interactions among involved
entities• More efforts at T2E to manage the NAPTR RRs
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Reference Model II (T2E=TSP)T1E
T2E/TSP End User
LegendASP Application Service ProviderTIE Tier 1 Entity (Registry)T2E Tier 2 Entity (Registrar)TSP Telephony Service Provider
ASP
A’
C’
New T2E/TSP
E’
B’
D’
** End User can be the end user itself or an agent authorized to represent the end user.** TSP can offer application services also. The “TSP” entity performs functions specific to the TSP.
12/18/2000
Reference Model II – Pros & Cons Pros:• Fewer interfaces to deal with• Easier to verify EU’s identity and ownership of the TN• More incentives for TSPs to get involved in enum process (e.g., verify
EU’s ownership of a TN and inform T1E about TN service disconnect)
Cons: • Only TSPs can be T2E, non-competitive if there is only one TSP in a
serving market• Non-TSPs cannot be T2E
– (except through delegation from TSP)
• EUs cannot be T2E for their own TNs• EUs cannot get enum service if none of TSPs in the serving market
offers enum service
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Telephony Service Specific Records
• Are there services for which the TSP should have right to put records in ENUM?
• How can TSP control records in Tier 2 of end user choice?
• How might these records be distinguished?• Alternative is to treat TSP like any other
application service provider• Ability of TSP to populate ENUM for customer
will facilitate penetration
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Major Issues
• Entity to be Service Registrar• Authentication of rights to number
– Number assignment– User identity
• Disconnect notification– Who informs Registry?
• Telephony service specific records
12/18/2000
References
• Patrik Faltstrom, “E.164 Number and DNS” RFC 2916.
• draft-pfautz-na-enum-01.txt
• draft-pfautz-yu-enum-adm-00.txt
• draft-ranalli-peek-walter-enum-t1roles-00.txt