Translation Patterns

Cisco CallManager uses translation patterns to manipulate dialed digits before routing a call. In some cases, the dialed number is not the number that is used by the system. In other cases, the dialed number is not a number that is recognized by the PSTN.

Digit manipulation and translation patterns are used frequently in cross-geographical distributed systems where, for instance, the office codes are not the same at all locations. In these situations, a uniform dialing plan can be created, and translation patterns can be applied to accommodate the unique office codes at each location. The following are additional examples when you can use translation patterns:

• Routing emergency calls to security desks and operator desks (such as sending emergency numbers to a local security office or routing '0' to the local operator extension)
• Hot lines with a need for private line, automatic ringdown (PLAR) functionality
• Extension mapping from the public to a private network

Translation patterns use the results of called-party transformations as a set of digits for a new analysis attempt. The second analysis attempt might match a translation pattern. In this case, Cisco CallManager applies the calling- and called-party transformations of the matching translation pattern and uses the results as the input for another analysis attempt. For example, you have a called-party transformation set up under a route pattern that transforms the dialed number 5555 to 0. You could then have a translation pattern defined to match the dialed number 0 and transform it to an operator extension or hunt group number. To prevent routing loops, Cisco CallManager breaks chains of translation patterns after ten iterations.

Translation Pattern Configuration

Configuration of a translation pattern is similar to configuration of a route pattern. Each pattern has calling- and called-party transformations and wildcard notation. The difference is that when Cisco CallManager applies the translation pattern, it starts the digit-analysis process over and routes the call through a new path if necessary.

To configure a translation pattern, choose the Route Plan menu and choose Translation Pattern. After you click the Add a New Translation Pattern hyperlink, the Translation Pattern Configuration window appears, as shown in Figure 11-12. You can define the route pattern to match (in the Translation Pattern field) and the calling- or called-party transformation settings that you want to apply.

Figure 11-12. Translation Pattern Configuration Window

Tip

Many new Cisco CallManager administrators get the translation and transformation terms confused. Cisco CallManager allows you to create translation patterns that contain both calling and called-party transformation masks to modify the caller ID or dialed-number information. Translation patterns are usually used to transform dialed digits, so the called-party transformation masks are more frequently used.

 

Practical Use of a Translation Pattern

Figure 11-13 shows an application for translation patterns. When the Direct Inward Dial (DID) range from the CO does not match the internal DN range, you can use a translation pattern to make the connection.

Figure 11-13. Practical Translation Pattern Example

In Figure 11-13, a company has a PSTN DID range of 408-555-1xxx. However, all of the internal four-digit extensions begin with 4xxx. When the company receives an incoming call, the company could use DDIs to remove the 555 from the beginning of the number. However, the 1xxx extension still remains. Instead, the translation pattern could apply a 4XXX called-party transformation mask. This mask would convert the 1xxx external DID range to a 4xxx internal range. After Cisco CallManager applies the transformation mask, it reanalyzes the dialed number and directs it to the correct internal extension. So, to summarize (and simplify), the following configuration would be created:

Translation Pattern: 4085551XXX

Called-Party Transformation Mask: 4XXX

Resulting Phone Number: 4XXX

If a call came into the DID 4085551111, CallManager would convert the dialed digits to 4111.

Route Plan Report