Ensure that adequate public IP addresses are assigned to the NAT pools to prevent port exhaustion. When multiple users and devices access Microsoft 365 or Office 365 using Network Address Translation (NAT) or Port Address Translation (PAT), you need to ensure that the devices hidden behind each publicly routable IP address do not exceed the supported number. Validate NAT pool size Validate the network address translation (NAT) pool size required for user connectivity. Maintain session persistence Make sure your firewall doesn’t change the mapped Network Address Translation (NAT) addresses or ports for UDP. For an example scenario, see Using Network Planner – example scenario. When you provide your network details and Teams usage, the Network Planner calculates your network requirements for deploying Teams and cloud voice across your organization’s physical locations. Network planner For help assessing your network, including bandwidth calculations and network requirements across your org’s physical locations, check out the Network Planner tool, in the Teams admin center.
It assesses your Microsoft 365 or Office 365 environment and identifies the most common configurations that you may need to update or modify before you can successfully roll out Teams. Advisor for Teams Advisor for Teams is part of the Teams admin center. For information about configuring firewall ports, go to Microsoft 365 and Office 365 URLs and IP ranges. Network optimization task Details External Name Resolution Be sure that all computers running the Teams client can resolve external DNS queries to discover the services provided by Microsoft 365 or Office 365 and that your firewalls are not preventing access.