Translation Patterns

CUCM uses translation patterns to manipulate digits before routing a call. The translation pattern can also be used to block certain patterns. Translation patterns are useful to manipulate the caller ID of incoming PSTN calls to allow the users to quickly return phone calls using the redial and missed-calls functionality. The caller ID from the PSTN may include only 10 digits while the system requires 11 digits prefixed with an access code of 9 to properly route outgoing calls. The translation pattern can prefix a 9 and a 1 to all incoming PSTN calls.

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 applied to accommodate the unique office codes at each location. Additional examples where translation patterns can be used are as follows:

■ Security desks and operator desks (abbreviated dialing)

■ Hotlines with a need for private line automatic ringdown (PLAR) functionality (security phones in elevators or on a college campus)

■ Extension mapping from a public to private network

Translation patterns use route-pattern style matching and transformation-mask digit manipulations. The resulting pattern is then re-analyzed by the system. The new pattern may match another translation pattern where digit transformation can occur once again. Eventually, the call is routed or blocked. To prevent call-routing loops, CUCM passes digits through translation patterns for only ten iterations.

Figure 12-11 illustrates the operation of a translation pattern. A translation pattern matches the dialed digits in a similar manner to the matching of a route pattern. The primary difference between route patterns and translation patterns is that translation patterns do not have a final call-routing destination (route list, gateway, or trunk). Translation patterns exist only to manipulate digits.

Figure 12-11 Translation Patterns

Route Pattern

Extend Call to Destination

To configure a translation pattern, navigate to Call Routing > Translation Pattern, as shown in Figure 12-12. The translation pattern identifies the dialed digit string to match and the calling- or called-party transformation settings that should be applied.

If the Block This Pattern radio button is selected, a cause code must be selected. Choose a value from the drop-down box:

No Error

Unallocated Number

Call Rejected

Number Changed

Invalid Number Format

Precedence Level Exceeded

The transformation settings are not applicable if the Block This Pattern radio button is selected.

If the translation pattern contains an @ sign, a numbering plan and route filter can be selected to match certain number patterns of the selected numbering plan.

Translation patterns are processed as urgent priority by default, and the Urgent Priority check box cannot be removed from a translation pattern. An overlapping dial plan involving a translation pattern could result in call-routing issues.

Figure 12-12 Translation Pattern Configuration

Figure 12-12 Translation Pattern Configuration


Route Option

Transformation Settings


Route Option

Transformation Settings

When the direct inward dialing (DID) range from the central office (CO) does not match the internal DN range, a translation pattern can be used to map the PSTN number to the internal DNs.

Figure 12-13 shows a scenario in which a company has a PSTN DID range of 408 555-1XXX, whereas the internal four-digit extensions begin with 4XXX. When the company receives an incoming call, the company uses a translation pattern that matches the assigned PSTN DID range (408 555-1XXX). The called-party transformation mask of 4XXX is applied against the translation pattern of 408 555-1XXX, resulting in a 4XXX dialed number. After CUCM applies the transformation mask, it performs a new call-routing lookup for the translated four-digit number, finds the DN in its call-routing table, and routes the call to the corresponding IP phone.

Figure 12-13 Translation Pattern Example

PSTN DID Range Does Not Match Internal Range

Translation Pattern = 408 555-1XXX Called-Party Transform Mask=4XXX

Translation Pattern = 408 555-1XXX Called-Party Transform Mask=4XXX

Internal Extensions 4XXX

An additional translation pattern of XXXX with a called-party transformation mask of 4111 can be used to route calls of unidentified extensions to the company operator. Assume that the DN of 4333 no longer exists in the system because that user (Dennis) won the lottery for $10 million and decided that he was going to play his guitar all day long instead of working. When a call comes in from the PSTN to 408 555-1333, the call is translated to 4333. Because 4333 no longer exists, it matches the generic XXXX translation pattern, and the call is routed to the company operator at extension 4111. Josephine (the company operator) instructs the outside caller that Dennis can be reached on his cell phone because he is home playing Metallica on his guitar.

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  • brigitte hoffmann
    How we can see the trace of translation pattern on cisco?
    11 months ago
  • christian
    How to configure translation pattern in cucm when incoming call direct to extension?
    5 months ago

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