ENUM (e164.arpa): background, scope, and coordination steps
Dear colleagues, This message summarises recent discussion regarding ENUM (e164.arpa) and clarifies the scope and next steps. The RIPE NCC has operated the e164.arpa registry for many years under instructions and coordination arrangements established with the ITU-T and IAB. These arrangements, and the operational context for how the registry is run, are described here: https://www.ripe.net/manage-ips-and-asns/dns/enum/iab-instructions/ Recently, a request was raised in the RIPE Database Working Group to support ENUM (e164.arpa) in RDAP for querying the RIPE Database. We noted that RDAP support for ENUM is not currently implemented, but could be added if there is clear interest. We also checked current query patterns and found a few hundred ENUM-related queries per day in DNS and in Database; so low usage, but not zero. Following discussion on the Database WG mailing list, including replies in support, we proposed implementing RDAP support for ENUM. While this is a limited operational change, it was recognised that anything touching E.164 and e164.arpa can raise political questions that go beyond the purely technical. As e164.arpa is directly linked to the ITU E.164 numbering system, the relevant points of contact are typically national administrations and the entities they designate. This led us to consult ITU-T Study Group 2 to clarify the status of ENUM and its usage and needs for ongoing support. ITU-T will ask member states for their feedback and share this with us. ITU-T provides an established and coordinated channel to reach those administrations, and importantly confirm whether any delegating authorities still rely on the service, so our technical decisions are informed by real-world use and help us avoid unnecessary operational risk, confusion, or compliance headaches (including in the context of regulatory frameworks such as NIS2). We are also reaching out to the IAB regarding these operations, which the RIPE NCC performs under its instruction on behalf of the global DNS and Internet community. I am sharing this message with the DNS, Database, Cooperation and RIPE NCC Services Working Group mailing lists to ensure all relevant working groups are informed. If you wish to share thoughts in response, please reply to the thread on the RIPE NCC Services WG mailing list. Best regards, Hisham Ibrahim Chief Community Officer, RIPE NCC
Dear colleagues, I would like to follow up on my previous message regarding ENUM (e164.arpa) and share a brief update on where things currently stand. As noted earlier, the RIPE NCC has been reviewing the operational status of the e164.arpa registry in light of its very limited usage, recent discussion in the RIPE Database Working Group, and the broader considerations surrounding the service operated by the RIPE NCC. Since my last email, the Internet Architecture Board (IAB) has discussed the matter at its last meeting. At this stage, the IAB has indicated that it would like to hear further feedback from the community before taking any further position. ITU-T has also initiated a consultation with Member States on the possible closure of the ENUM system under e164.arpa. As mentioned previously, this is an important part of understanding whether the service is still needed by the relevant delegating authorities and whether there is a continued operational justification for maintaining it. While the immediate trigger was a limited operational question, the topic also touches on broader considerations around community input, governance responsibilities, and coordination with relevant external bodies such as the IAB, IANA and ITU-T. For the RIPE NCC, the goal remains to approach this carefully and transparently: to understand whether there is still a real need for the service, to avoid unnecessary operational or compliance risk, and to ensure that any future steps are informed by both community feedback and the views of the appropriate stakeholders. I will present on this topic at RIPE 92, where I will provide more background, summarise the discussions to date, and invite further feedback from the RIPE community. In the meantime, I encourage anyone with views on this matter to share them on the RIPE NCC Services Working Group mailing list so that the discussion can continue openly and with the benefit of community input. Best regards, Hisham Ibrahim Chief Community Officer RIPE NCC On Tue, 17 Feb 2026 at 16:15, Hisham Ibrahim <HMI@ripe.net> wrote:
Dear colleagues,
This message summarises recent discussion regarding ENUM (e164.arpa) and clarifies the scope and next steps.
The RIPE NCC has operated the e164.arpa registry for many years under instructions and coordination arrangements established with the ITU-T and IAB. These arrangements, and the operational context for how the registry is run, are described here: https://www.ripe.net/manage-ips-and-asns/dns/enum/iab-instructions/
Recently, a request was raised in the RIPE Database Working Group to support ENUM (e164.arpa) in RDAP for querying the RIPE Database. We noted that RDAP support for ENUM is not currently implemented, but could be added if there is clear interest. We also checked current query patterns and found a few hundred ENUM-related queries per day in DNS and in Database; so low usage, but not zero.
Following discussion on the Database WG mailing list, including replies in support, we proposed implementing RDAP support for ENUM. While this is a limited operational change, it was recognised that anything touching E.164 and e164.arpa can raise political questions that go beyond the purely technical.
As e164.arpa is directly linked to the ITU E.164 numbering system, the relevant points of contact are typically national administrations and the entities they designate. This led us to consult ITU-T Study Group 2 to clarify the status of ENUM and its usage and needs for ongoing support. ITU-T will ask member states for their feedback and share this with us.
ITU-T provides an established and coordinated channel to reach those administrations, and importantly confirm whether any delegating authorities still rely on the service, so our technical decisions are informed by real-world use and help us avoid unnecessary operational risk, confusion, or compliance headaches (including in the context of regulatory frameworks such as NIS2).
We are also reaching out to the IAB regarding these operations, which the RIPE NCC performs under its instruction on behalf of the global DNS and Internet community.
I am sharing this message with the DNS, Database, Cooperation and RIPE NCC Services Working Group mailing lists to ensure all relevant working groups are informed. If you wish to share thoughts in response, please reply to the thread on the RIPE NCC Services WG mailing list.
Best regards, Hisham Ibrahim Chief Community Officer, RIPE NCC
Hi Hisham, If you already have the e164.arpa numbers/stats usage, it would be more useful to publish it instead of waiting for your presentation. Or at least say what your assessment is based on. -- Best regards, Sergey
On Mar 31, 2026, at 15:09, Hisham Ibrahim <HMI@ripe.net> wrote:
Dear colleagues, I would like to follow up on my previous message regarding ENUM (e164.arpa) and share a brief update on where things currently stand. As noted earlier, the RIPE NCC has been reviewing the operational status of the e164.arpa registry in light of its very limited usage, recent discussion in the RIPE Database Working Group, and the broader considerations surrounding the service operated by the RIPE NCC. Since my last email, the Internet Architecture Board (IAB) has discussed the matter at its last meeting. At this stage, the IAB has indicated that it would like to hear further feedback from the community before taking any further position. ITU-T has also initiated a consultation with Member States on the possible closure of the ENUM system under e164.arpa. As mentioned previously, this is an important part of understanding whether the service is still needed by the relevant delegating authorities and whether there is a continued operational justification for maintaining it.
While the immediate trigger was a limited operational question, the topic also touches on broader considerations around community input, governance responsibilities, and coordination with relevant external bodies such as the IAB, IANA and ITU-T. For the RIPE NCC, the goal remains to approach this carefully and transparently: to understand whether there is still a real need for the service, to avoid unnecessary operational or compliance risk, and to ensure that any future steps are informed by both community feedback and the views of the appropriate stakeholders. I will present on this topic at RIPE 92, where I will provide more background, summarise the discussions to date, and invite further feedback from the RIPE community. In the meantime, I encourage anyone with views on this matter to share them on the RIPE NCC Services Working Group mailing list so that the discussion can continue openly and with the benefit of community input. Best regards, Hisham Ibrahim Chief Community Officer RIPE NCC
On Tue, 17 Feb 2026 at 16:15, Hisham Ibrahim <HMI@ripe.net> wrote: Dear colleagues,
This message summarises recent discussion regarding ENUM (e164.arpa) and clarifies the scope and next steps. The RIPE NCC has operated the e164.arpa registry for many years under instructions and coordination arrangements established with the ITU-T and IAB. These arrangements, and the operational context for how the registry is run, are described here: https://www.ripe.net/manage-ips-and-asns/dns/enum/iab-instructions/ Recently, a request was raised in the RIPE Database Working Group to support ENUM (e164.arpa) in RDAP for querying the RIPE Database. We noted that RDAP support for ENUM is not currently implemented, but could be added if there is clear interest. We also checked current query patterns and found a few hundred ENUM-related queries per day in DNS and in Database; so low usage, but not zero.
Following discussion on the Database WG mailing list, including replies in support, we proposed implementing RDAP support for ENUM. While this is a limited operational change, it was recognised that anything touching E.164 and e164.arpa can raise political questions that go beyond the purely technical.
As e164.arpa is directly linked to the ITU E.164 numbering system, the relevant points of contact are typically national administrations and the entities they designate. This led us to consult ITU-T Study Group 2 to clarify the status of ENUM and its usage and needs for ongoing support. ITU-T will ask member states for their feedback and share this with us.
ITU-T provides an established and coordinated channel to reach those administrations, and importantly confirm whether any delegating authorities still rely on the service, so our technical decisions are informed by real-world use and help us avoid unnecessary operational risk, confusion, or compliance headaches (including in the context of regulatory frameworks such as NIS2). We are also reaching out to the IAB regarding these operations, which the RIPE NCC performs under its instruction on behalf of the global DNS and Internet community. I am sharing this message with the DNS, Database, Cooperation and RIPE NCC Services Working Group mailing lists to ensure all relevant working groups are informed. If you wish to share thoughts in response, please reply to the thread on the RIPE NCC Services WG mailing list.
Best regards, Hisham Ibrahim Chief Community Officer, RIPE NCC ----- To unsubscribe from this mailing list or change your subscription options, please visit: https://mailman.ripe.net/mailman3/lists/ncc-services-wg.ripe.net/ As we have migrated to Mailman 3, you will need to create an account with the email matching your subscription before you can change your settings. More details at: https://www.ripe.net/membership/mail/mailman-3-migration/
Dear colleagues, I noticed that discussions on the ENUM service have been taking place across several Working Group mailing lists. I understand that many of you are subscribed only to the mailing list most relevant to your work, so I wanted to bring the discussions together in this update. For those interested in reading more, I have included links to the relevant mailing list archives below. Cooperation (where most of the discussion has taken place so far): https://mailman.ripe.net/archives/list/cooperation-wg@ripe.net/thread/CYGBCW... https://mailman.ripe.net/archives/list/cooperation-wg@ripe.net/thread/W45FPG... DNS: https://mailman.ripe.net/archives/list/dns-wg@ripe.net/thread/MQRA6ALDT55DOA... Services: https://mailman.ripe.net/archives/list/ncc-services-wg@ripe.net/thread/5E4HT... https://mailman.ripe.net/archives/list/ncc-services-wg@ripe.net/thread/QDXL2... Database: https://mailman.ripe.net/archives/list/db-wg@ripe.net/thread/3PIG2F4EU2F2WBL... As this is a RIPE NCC service, I plan to present it at the Services Working Group session. I will also reach out to a number of other Working Group chairs to see whether there may be an opportunity to discuss it during the working group session at RIPE 92. Regards Hisham
Hi Hisham!
I noticed that discussions on the ENUM service have been taking place across several Working Group mailing lists.
You could always awaken https://www.ripe.net/community/wg/inactive-working-groups/enum/ ;) Cheers! Sander
participants (3)
-
Hisham Ibrahim -
Sander Steffann -
Sergey Myasoedov