What are TON and NPI settings?

TON and NPI settings are SMS-MT features that allow senders to manage originator and destination settings.

Type of Number (TON) specifies if the number is a full international number, country code number, or an alphanumeric sender.

While Numbering Plan Indicator (NPI) specifies the numbering standard, the given mobile number is being followed.

The easiest way to ensure messages are reliably sent is to send a TON/NPI = 1 and ensure that the source_addr is an E.164 formatted number.

What are TON and NPI defaults?

For SMPP environments, these are the rules for setting the source_addr_ton and source_addr_npi values:

  • If the source code/address is a short code, TON is set to 3, and NPI is set to 0
  • If the sender address is alphanumeric or non-numeric, TON is set to 5, and NPI is set to 0
  • If the sender starts with “+,” TON and NPI are set to 1
  • If none of the conditions are met, TON is set to 0, and NPI is set to 1
  • If the sender is blank, both are set to 0
  • If the recipient starts with a “+,” TON and NPI are set to 1. Otherwise, TON is set to 0, and NPI is set to 1.

How does SMPP specification define TON values?

The SMPP specification defines TON values as follows:

  • Unknown = 0
  • International = 1
  • National = 2
  • Network-Specific = 3
  • Subscriber Number = 4
  • Alphanumeric = 5
  • Abbreviated = 6

What are possible NPI values in SMPP?

Possible NPI values are:

  • Unknown = 0
  • ISDN/telephone numbering plan (E163/E164) = 1
  • Data numbering plan (X.121) = 3
  • Telex numbering plan (F.69) = 4
  • Land Mobile (E.212) = 6
  • National numbering plan = 8
  • Private numbering plan = 9
  • ERMES numbering plan (ETSI DE/PS 3 01-3) = 10
  • Internet (IP) = 13
  • WAP Client Id (to be defined by WAP Forum) = 18
Jun 9th, 2021
2 min read

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