Technical data

How Numbers Are Processed
Dialogic
®
Diva
®
SIPcontrol
TM
Software 1.8 Reference Guide page 52
CHAPTER 9
How Numbers Are Processed
The Dialogic
®
Diva
®
SIPcontrol
TM
Software provides two mechanisms for number processing. Both mechanisms
can be used together:
1. Number normalization based on a dialplan
as described below.
2. Number modification using regular expressions
as described on page 53.
Number normalization based on a dialplan
The number normalization based on a dialplan can work in an environment in which the Diva SIPcontrol software
is connected to a private SIP network and a public switched telephone network (PSTN), optionally with a PBX
between the PSTN and the Diva SIPcontrol software. If the Diva SIPcontrol software is used as a gateway between
a private circuit switched network and a public SIP-based network, the number normalization function of the
Diva SIPcontrol software should not be used.
The Diva SIPcontrol software version 1.8 also supports dialplans using the North American numbering plan
(NANP). See North-American numbering plan:
on page 38 for more information.
The number normalization is done in two steps:
1. The received called, calling and redirected numbers are analyzed based on the dialplan configured for the
PSTN Interface or SIP Peer.
2. The number is converted into the configured target format. Six target formats are available:
• International number with prefixes: All numbers are converted to an international number with the
prefix for international calls and, if required, an outside access digit.
• International number with number type: All numbers are converted to an E.164 number with the
number type flag set to "international" ("+" is used in SIP addresses).
• National number with prefixes: If possible, all numbers are converted to a national number with the
prefix for national calls and an outside access digit, as required. Exception: Numbers with different country
code will be converted to an international number with prefix for international calls and outside access
digit, if required.
• National number with number type: If possible, all numbers are converted to a national number with
the number type flag set to "national". Exception: Numbers with different country code will be converted
to an international number with number type set to "international". Note: This target format should not
be used for calls to SIP networks.
• Extension only with prefixes: All numbers are reduced as much as possible; only the required prefixes
are prepended.
• Extension only with number type: All numbers are reduced as much as possible. Instead of prefixes
the appropriate number type is set. Note: This target format should not be used for calls to SIP networks.
Important information about the outside access digit configuration
• Configure the outside access digit only if there is a PBX between the PSTN and the Diva SIPcontrol software,
and if this PBX requires the outside access digit for external calls. If you need to configure the outside access
digit, also configure the following related options:
• Incoming PSTN access code provided by the PBX: This option defines whether the Diva SIPcontrol
software expects the outside access digit in the calling number in external calls from the PBX.
The PBX normally prepends the outside access digit to the calling number in incoming external calls in
order to enable callback functionality at internal phones. If this is the case, enable this option.
• PSTN access code provided by the SIP caller: This option defines whether the Diva SIPcontrol software
expects the outside access digit in the called number in external calls from the SIP side to the PSTN.
It is normally required to prepend the outside access digit to call an external number from an internal
phone. In this case, these are phones on the SIP side. However, in some configurations this is not required,
especially in a configuration that is part of the North-American numbering plan (NANP), where an internal
number can be identified based on its length. If it is possible to identify an internal call purely by the