The Virtual Number Registration Protocol VNRP

1
The Virtual Number Registration Protocol (VNRP)

• Michael Haberler
• Internet Foundation Austria
• mah_at_eunet.at
• June 2004

2
backdrop

• Broadband Voice naturally segrates into three
  components, potentially provided by different
  entities even if offered as a bundle
• on-net/on-net - SIP hosting service by ITSP
• net-to-pstn termination DIY by ITSP gateway or
  e.g Level3, Ibasis, delathree SIP termination
• pstn to on-net useful for virtual presence in
  different calling areas (see SIPphone virtual
  numbers, Vonage options)
• if each ITSP does it herself, n(calling areas)
  by m(number of ITSPs) gateway rollout required
• this is a candidate for a new wholesale service,
  likely at a flat rate per month
• a potential cottage industry
• a standard way to provision such a service is
  desirable to prevent interface explosion for
  ITSPs bundling such services
• an ENUM delegation for the number would be a
  natural fit this makes the number usable both
  on-net and off-net
• not limited to voice could be SMS-to-IM,
  Fax-to-SMTP, MMS-to-SMTP too potentially some in
  parallel (eg Voice, SMS and MMS or Fax,SMS
  MMS Voice Fax on same number unlikely)

3
usage scenario user view

• ITSP website presents option for access numbers
  in any of several calling areas
• choice of next-free, one-in-a-list or vanity
  number
• user selects number, agrees to charges
• ITSP configures mapping of number to SIP URI
• where available, enters number mapping in ENUM
  makes number visible also on-net (maybe in a
  private tree, e164.arpa, or both)
• if a generic gateway is available for the number
  range used, (I) is all that needs to be done
• number is active can be called
• Step 3 is the provisioning step which is
  addressed by the VNR protocol

4
VNRP Properties and business model assumption

• account signup between ITSP and VN provider (VNP)
  assumed out-of-band to VNRP including
  credentials exchange could be even a
  credit-card deposit as a start maybe through
  website
• ITSP configures VNRP client stub in his
  provisioning system activated by user choice
• VNP provides VNRP service called on-demand by
  ITSP
• a VN registration likely involves a per-month
  price which is charged to the ITSP/deducted from
  deposit

5
VNRP operations

• list calling areas (cc/area code/range/number of
  digits mask)
• list rate centers for calling area (might be
  no-op outside US)
• list gateway services (SIP, Fax, SMS, MMS,
  H.323...) for calling area
• reuse enumservices definition as service selector
• list next free number for rate center/calling/serv
  ice area combination
• register number and SIP URI for x months period
• optionally register ENUM domain for number
• optionally transfer directory entry or user
  refernce at ITSP might be needed in some
  jurisdictions
• extend number validity period
• cancel number
• list info for number

6
VNRP design

• Id suggest an XML based implementation
• options are
• Extensible Provisioning Protocol with new
  mappings (more IETF affine)
• SOAP easy on interface requirements, but sorta
  kludgy
• both can be over TLS
• somebodys got to flesh out the XML objects and
  flows, and do a pilot implementation
• what would be really cool is an VNRP server,
  sitting on a database, and driving Asterisk
  that could drive adoption

7
acknowledgements

• some ideas my own see
• The generic ENUM-driven gateway see slides at
  http//enum.nic.at/documents/AETP/Presentations/Ot
  her/0025-The_generic_ENUM-driven_VoIP_gateway.ppt
• draft specification http//enum.nic.at/documents/
  AETP/Presentations/Austria/0037-2004-05_The_Generi
  c_ENUM_driven_Gateway-draft_specification_v04.doc
• some ideas are lifted from Bret Mingo at
  coretel.net bret_at_coretel.net
• see also http//devapi.coretel.net/VoIP.html