• CUCM uses closest match logic to select the best pattern.
• Where there are multiple matches, the selection is based on:
  • It matches the dial digit
  • It matches the fewest strings other than the dialed string

• Place devices with similar digit manipulation requirement in the same Route Group
• Configure distribution algorithm

• A prioritized list of Route Group
• Use Route List to prioritize over different medium e.g. WAN over PSTN
• Route List Detail configuration allow digit manipulation per route group

• If you configure digit manipulation in the route pattern, the Call Detail Record (CDR) records the dialed number after the digit manipulation has occurred. If you configure digit manipulation only in the route group, the CDR records the actual dialed number prior to the digit manipulation.
• Similarly, if you configure digit manipulation in the route pattern, the IP phone display of the calling party will show the manipulated number. If you configure digit manipulation only in the route group, the manipulations will be transparent to the end user.
• If you are performing several digit manipulations in a route pattern or a route group, the order in which the transformations are performed can impact the resulting calling and called party numbers used for the call. Unified CM performs the following major types of digit manipulations in the order indicated:
  1. Discarding digits
  2. Called/calling party transformations
  3. Prefixing digits
  4. Called/calling party transformation patterns

• To use + in its literal sense, precede it with the escape character \ to differentiate it from the regular expression operator +, which means one or more instances of the preceding character.

For example:

• \+14085264000 means +14085264000
• 2+ means 2, or 22, or 222, and so forth

• Overlap sending means that Unified CM keeps collecting digits as they are dialed by the end users, and passes them on to the PSTN as they are dialed.
• Overlap receiving means that Unified CM receives the dialed digits one-by-one from a PRI PSTN gateway, and it then waits for completion of the dialed string before attempting to route the call to an internal destination. To enable overlap receiving, set the OverlapReceivingFlagForPRI service parameter to True.