Scenario: Remote ip phone in customers house. Phone system at place of business. We are being told the system needs three ip address to work.

Question: 1.Why do you need three ip addresses? 2.How many of them are needed for the ip phone to talk to the phone system and function properly? 3. Could any of the ports that need ip addresses be on the public side that need outside access and leave the ones that dont on the private network?

Any help would be appreciated guys!

What kind of system do you have? What is in the layout of the system? Do you have an MGI card or OAS card? We need a little more info to be able to help you answer this question.

Depending on the config of the system will depend on how many ip address's you need.
You will also need todo some port fowarding on the public side