Incoming Call Pattern Guidelines
When you configure either the Primary Rate Interface (PRI) or Basic Rate Interface (BRI) interface for Time Division Multiplexing (TDM), you can set a list of extension numbers and match patterns for routing incoming calls. You can specify exact matches as well as patterns that route to a range of destinations.
For example, suppose that a company with 300 employees deploys the Oracle® Enterprise Session Border Controller (ESBC) and connects to the PSTN network by way of an ISDN interface. The company allocates 300 extension numbers: numbers 7100 - 7399 for employee desk phones, and number 70 for the reception desk so that it is easy to remember.
The service provider assigns the prefix 49331200 to the company, so the reception desk PSTN number becomes 4933120070 and the employee numbers become 493312007100, 493312007101-493312007399.
The incoming pattern in this example will match either the reception desk number or one of the other extensions. When the match is successful, the received number is complete and the call setup can proceed. You can configure TDM to match the reception desk number as a whole: "4933120070," and to match any of the other extensions through a single pattern: "_493312007[1-3]XX". To put these rules together, set the incoming-pattern parameter to the following value: "4933120070|_493312007[1-3]XX".
In match patterns, separate single extension numbers with the vertical bar (|) character. Start a match pattern with the underscore (_) character before the first number of the pattern. Do not use the underscore with an exact match. Type the exact match, starting with the first number because an exact match does not use an extension pattern. Note the meaning of the following characters:
X matches any digit from 0-9
Z matches any digit from 1-9
N matches any digit from 2-9
[1237-9] matches any digit in the brackets (in this example, 1,2,3,7,8,9).
. wildcard, matches one or more characters
! wildcard, matches zero or more characters immediately