Figure 3-76: Phone Context Table - AudioCodes Mediant 2000 User Manual

3.3.7.8.2 Mapping NPI/TON to SIP Phone-Context
The 'Phone-Context Table' page is used to map Numbering Plan Indication (NPI) and Type
of Number (TON) to the SIP Phone-Context parameter. When a call is received from the
ISDN, the NPI and TON are compared against the table and the matching Phone-Context
value is used in the outgoing SIP INVITE message. The same mapping occurs when an
INVITE with a Phone-Context attribute is received. The Phone-Context parameter appears
in the standard SIP headers where a phone number is used (Request-URI, To, From,
Diversion).
For example, for a Tel-to-IP call with NPI/TON set as E164 National (values 1/2), the device
sends the outgoing SIP INVITE URI with the following settings: "sip:12365432;phone-
context= na.e.164.nt.com". This is configured for entry 3 in the figure below. In the opposite
direction (IP-to-Tel call), if the incoming INVITE contains this Phone-Context (e.g. "phone-
context= na.e.164.nt.com"), the NPI/TON of the called number in the outgoing SETUP
message is changed to E164 National.

To configure the Phone-Context tables:
1. Open the 'Phone Context Table' page (Configuration tab > Protocol Configuration
menu > Manipulation Tables submenu > Phone Context Table
2. Configure the Phone Context table according to the table below.
3. Click the Submit
4. To save the changes to flash memory, refer to ''
Notes:
SIP User's Manual
Figure 3-76: Phone Context Table Page
button to save your changes.
•
Several rows with the same NPI-TON or Phone-Context are allowed. In
such a scenario, a Tel-to-IP call uses the first match.
•
Phone-Context '+' is a unique case as it doesn't appear in the Request-
URI as a Phone-Context parameter. Instead, it's added as a prefix to the
phone number. The '+' isn't removed from the phone number in the IP-to-
Tel direction.
•
You can also configure the Phone Context table using the ini file table
parameter PhoneContext (refer to ''Number Manipulation and Routing
Parameters'' on page
Saving Configuration''
348 ).
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page item).
on page 173 .
Document #: LTRT-68809