When call is made from an IP Phone, phone initially displays the number dialed by user. As call goes to next call state, phone can update the dialed number depends on digit manipulation techniques being applied. This depends on various system configuration. Few users want to display original dialed number and other wants to see the actual number being dialed. There were various discussions in CSC on this subject. I thought to summarize all these available options in one place. There could be many other ways as well but I've seen most of the users have used either of the following mechanism to solve their issue.
Let's stick to one flow and see how different options are available with us to take care of the situation. Caller dials the number 1234 and this number is translated to 9925801882 using translation pattern. Hence caller sees 9925801882 on phones display instead of 1234. User requirement is to still see 1234. Let's analyze the different options available.
1. Always Display Original Dialed Number
This is CUCM Service Parameter and by default set to False. Once change it to True, phone will always display the original dialed number. Hence in our example, phone will display 1234 on its screen.
Be aware that this is service parameter and hence it has global impact and will be applicable for all calls.
2. Remote Number Transformation CSS
Create calling party transformation pattern to change the number from 9925801882 to 1234. Keep it in relevant partition and assign the CSS to Remote Number Calling Party Transformation CSS on device page.
Set the service parameter 'Apply Transformations on Remote Number' to True. Default is False.
3. SIP Profiles
You can instruct gateway using SIP profiles to send desired number in rpid header so that phones display the connected number accordingly.
In the current example, translation pattern is applied in CUCM to translate the number from 1234 to 9925801882 however we've a choice to do the same translation in gateway instead of CUCM. If done so, gateway will update the connected number information in rpid header. If we block the rpid header viz gateway doesn't send this header to CUCM, original dialed number will be displayed on callers phone. Following is the step to disable rpid header in gateway;
sip-ua no remote-party-id
PS: For H.323, equivalent command is 'no supplementry-service h225-notify cid-update'
5. Route Pattern
Route pattern level digit manipulation can also be used to control the called number display with various permutations and combinations however I've never used it before.