Inbound and outbound RealTime Service (RTS) ports and needed IP addresses

Overview of inbound and outbound ports that RTS is using:

Note: The ports listed below are valid no matter where Realtime Service (RTS) is installed (on-premise or in the cloud). If installed behind a firewall, then appropriate inbound ports and outbound ports should be used for RTS to communicate with other components.

RTS = RealTime Service (Windows services)
RTM = RealTime Manager

Note: RealTime Services uses the following DNS names for communicating with Office 365, Exchange Online, Azure AD:

For Azure Cloud:

• login.windows.net
• graph.windows.net
• autodiscover-s.outlook.com

For German Cloud:

• login.microsoftonline.de
• graph.cloudapi.de
• autodiscover-s.outlook.de

For Chinese Cloud:

• login.chinacloudapi.cn
• graph.chinacloudapi.cn
• autodiscover-s.partner.outlook.cn

Overview of needed IP addresses:

You can have an overview of IP addresses RTS is using when talking to Office 365 by visiting this page: 

https://learn.microsoft.com/en-us/microsoft-365/enterprise/urls-and-ip-address-ranges

The above dns names are listed in the following sections:

- Microsoft 365 Common and Office Online
- Exchange Online

But as the IP addresses change frequently, we do not recommend locking down the traffic to specific addresses. Rather consider using Conditional access if this is a possibility. Or using the Json or pac file to ensure that your public firewall has the correct addresses.