If you are talking about the Number of DNIS’s you need.
Usually, The DNIS is “in use” from the time the router makes the decision until the receiving site PG gets a route request, and informs the Central Controller.
SO
First, calculate the time between the router decision and the call arriving on the site.
Next, calculate the number of calls you will be sending to that site in that time frame.
Then, Take that number and add a cushion. I think Cisco recommends 50%
Things to consider when adding a cushion:
1. Calls will hold up the temp DNIS for a longer time if they abandon in transfer (default is 20 seconds, could be more – Check your translation route timeout settings in the reg..) So when calculating Abandons use the translation route timeout figure instead of the transfer time.
2. Call volume spikes.
Hope this helps
