When an IP phone extension, for example 234455, calls an off net number, or a Public Switched Telephone Network (PSTN) number, through the H323 gateway, the window displays the number as #1234#xxxx, which leads to confusion.
When a call routes through a translation or route pattern, the connected number display updates to show the modified number. In order to turn off these updates to the phone display so that the phone shows only the digits exactly as dialed, set the Always Display Original Dialed Number Cisco Unified CallManager service parameter to true. When this service parameter specifies true, the phone displays only the dialed digits for the duration of the call. Refer to the Enabling Call Display Restrictions section of Call Display Restrictions for more information on this and other display issues.