Port and protocol requirements for servers

Summary: Review the port usage considerations before implementing Skype for Business Server.

Skype for Business Server requires that specific ports on the external and internal firewalls are open. Additionally, if Internet Protocol security (IPsec) is deployed in your organization, IPsec must be disabled over the range of ports used for the delivery of audio, video, and panorama video.

While this might seem a bit daunting, the heavy lifting for planning this can be done using the Skype for Business Server 2015 Planning Tool. Once you've gone through the wizard's questions about what features you plan to use, for each site you define you can view the Firewall Report within the Edge Admin Report, and use the information listed there to create your firewall rules. You can also make adjustments to many of the names and IP addresses used, for details see Review the Firewall Report. Keep in mind you can export the Edge Admin Report to an Excel spreadsheet, and the Firewall Report will be one of the worksheets in the file.

You find the information in these tables in diagram form by reviewing the Protocol Workloads poster linked off of the Technical diagrams for Skype for Business Server 2015 article.

Note

  • If you're implementing Skype for Business Online (Microsoft 365 or Office 365) refer to Microsoft 365 and Office 365 URLs and IP address ranges. Hybrid environments will need to reference this topic and also Plan hybrid connectivity.
  • You can have hardware or software firewall. We don't require specific models or versions. What matters is what ports are added to an allowlist so the firewall won't impair the functioning of Skype for Business Server.

Port and Protocol Details

This section summarizes the ports and protocols used by servers, load balancers, and clients in a Skype for Business Server deployment.

Note

When Skype for Business Server starts, it opens the required ports in the Windows Firewall. Windows Firewall should already be running in most normal applications, but if it is not being used Skype for Business Server will function without it.

For details about firewall configuration for edge components, see Edge Server scenarios in Skype for Business Server 2015.

The following table lists the ports that need to be open on each internal server role.

Required Server Ports (by Server Role)

Server role Service name Port Protocol Notes
All Servers SQL Browser 1434 UDP SQL Browser for the local replicated copy of the Central Management Store database.
Front-End Servers Skype for Business Server Front-End service 5060 TCP Optionally used by Standard Edition servers and Front End Servers for static routes to trusted services, such as remote call control servers.
Front End Servers Skype for Business Server Front-End service 5061 TCP (TLS) Used by Standard Edition servers and Front End pools for all internal SIP communications between servers (MTLS), for SIP communications between Server and Client (TLS) and for SIP communications between Front End Servers and Mediation Servers (MTLS). Also used for communications with a Monitoring Server.
Front End Servers Skype for Business Server Front-End service 444 HTTPS
TCP
Used for HTTPS communication between the Focus (the Skype for Business Server component that manages conference state) and the individual servers.
This port is also used for TCP communication between Survivable Branch Appliances and Front End Servers.
Front End Servers Skype for Business Server Front-End service 135 DCOM and remote procedure call (RPC) Used for DCOM based operations such as Moving Users, User Replicator Synchronization, and Address Book Synchronization.
Front End Servers Skype for Business Server IM Conferencing service 5062 TCP Used for incoming SIP requests for instant messaging (IM) conferencing.
Front End Servers Skype for Business Server Web Conferencing service 8057 TCP (TLS) Used to listen for Persistent Shared Object Model (PSOM) connections from client.
Front End Servers Skype for Business Server Web Conferencing Compatibility service 8058 TCP (TLS) Used to listen for Persistent Shared Object Model (PSOM) connections from the Live Meeting client and previous versions of Skype for Business Server.
Front End Servers Skype for Business Server Audio/Video Conferencing service 5063 TCP Used for incoming SIP requests for audio/video (A/V) conferencing.
Front End Servers Skype for Business Server Audio/Video Conferencing service 57501-65535 TCP/UDP Media port range used for video conferencing.
Front End Servers Skype for Business Server Web Compatibility service 80 HTTP Used for communication from Front End Servers to the web farm FQDNs (the URLs used by IIS web components) when HTTPS is not used.
Front End Servers Skype for Business Server Web Compatibility service 443 HTTPS Used for communication from Front End Servers to the web farm FQDNs (the URLs used by IIS web components).
Front End Servers Skype for Business Server Web Compatibility service 8080 TCP and HTTP Used by web components for external access.
Front End Servers Web server component 4443 HTTPS HTTPS (from Reverse Proxy) and HTTPS Front End inter-pool communications for Autodiscover sign-in.
Front End Servers Web server component 8060 TCP (MTLS)
Front End Servers Web server component 8061 TCP (MTLS)
Front End Servers Mobility Services component 5086 TCP (MTLS) SIP port used by Mobility Services internal processes
Front End Servers Mobility Services component 5087 TCP (MTLS) SIP port used by Mobility Services internal processes
Front End Servers Mobility Services component 443 HTTPS
Front End Servers Skype for Business Server Conferencing Attendant service (dial-in conferencing) 5064 TCP Used for incoming SIP requests for dial-in conferencing.
Front End Servers Skype for Business Server Conferencing Attendant service (dial-in conferencing) 5072 TCP Used for incoming SIP requests for Attendant (dial in conferencing).
Front End Servers that also run a Collocated Mediation Server Skype for Business Server Mediation service 5070 TCP Used by the Mediation Server for incoming requests from the Front End Server to the Mediation Server.
Front End Servers that also run a Collocated Mediation Server Skype for Business Server Mediation service 5067 TCP (TLS) Used for incoming SIP requests from the PSTN gateway to the Mediation Server.
Front End Servers that also run a Collocated Mediation Server Skype for Business Server Mediation service 5068 TCP Used for incoming SIP requests from the PSTN gateway to the Mediation Server.
Front End Servers that also run a Collocated Mediation Server Skype for Business Server Mediation service 5081 TCP Used for outgoing SIP requests from the Mediation Server to the PSTN gateway.
Front End Servers that also run a Collocated Mediation Server Skype for Business Server Mediation service 5082 TCP (TLS) Used for outgoing SIP requests from the Mediation Server to the PSTN gateway.
Front End Servers Skype for Business Server Application Sharing service 5065 TCP Used for incoming SIP listening requests for application sharing.
Front End Servers Skype for Business Server Application Sharing service 49152-65535 TCP Media port range used for application sharing.
Front End Servers Skype for Business Server Conferencing Announcement service 5073 TCP Used for incoming SIP requests for the Skype for Business Server Conferencing Announcement service (that is, for dial-in conferencing).
Front End Servers Skype for Business Server Call Park service 5075 TCP Used for incoming SIP requests for the Call Park application.
Front End Servers Skype for Business Server Audio Test service 5076 TCP Used for incoming SIP requests for the Audio Test service.
Front End Servers Not applicable 5066 TCP Used for outbound Enhanced 9-1-1 (E9-1-1) gateway.
Front End Servers Skype for Business Server Response Group service 5071 TCP Used for incoming SIP requests for the Response Group application.
Front End Servers Skype for Business Server Response Group service 8404 TCP (MTLS) Used for incoming SIP requests for the Response Group application.
Front End Servers Skype for Business Server Bandwidth Policy Service 5080 TCP Used for call admission control by the Bandwidth Policy service for A/V Edge TURN traffic.
Front End Servers Skype for Business Server File Share server access 445 SMB/TCP Used to retrieve Address book, meeting content, and other items stored on the File Share server.
Front End Servers Skype for Business Server Bandwidth Policy Service 448 TCP Used for call admission control by the Skype for Business Server Bandwidth Policy Service.
Front End Servers where the Central Management store resides Skype for Business Server Master Replicator Agent service 445 TCP Used to push configuration data from the Central Management store to servers running Skype for Business Server.
All Servers SQL Browser 1434 UDP SQL Browser for local replicated copy of Central Management store data in local SQL Server instance
All internal servers Various 49152-57500 TCP/UDP Media port range used for audio conferencing on all internal servers. Used by all servers that terminate audio: Front End Servers (for Skype for Business Server Conferencing Attendant service, Skype for Business Server Conferencing Announcement service, and Skype for Business Server Audio/Video Conferencing service), and Mediation Server.
Office Web Apps Servers 443 Used by Skype for Business Server to connect to Office Web Apps Server.
Directors Skype for Business Server Front-End service 5060 TCP Optionally used for static routes to trusted services, such as remote call control servers.
Directors Skype for Business Server Front-End service 444 HTTPS
TCP
Inter-server communication between Front End and Director. Additionally, client certificate publish (to Front End Servers) or validate if the client certificate has already been published.
Directors Skype for Business Server Web Compatibility service 80 TCP Used for initial communication from Directors to the web farm FQDNs (the URLs used by IIS web components). In normal operation, will switch to HTTPS traffic, using port 443 and protocol type TCP.
Directors Skype for Business Server Web Compatibility service 443 HTTPS Used for communication from Directors to the web farm FQDNs (the URLs used by IIS web components).
Directors Skype for Business Server Front-End service 5061 TCP Used for internal communications between servers and for client connections.
Mediation Servers Skype for Business Server Mediation service 5070 TCP Used by the Mediation Server for incoming requests from the Front End Server.
Mediation Servers Skype for Business Server Mediation service 5067 TCP (TLS) Used for incoming SIP requests from the PSTN gateway.
Mediation Servers Skype for Business Server Mediation service 5068 TCP Used for incoming SIP requests from the PSTN gateway.
Mediation Servers Skype for Business Server Mediation service 5070 TCP (MTLS) Used for SIP requests from the Front End Servers.
Persistent Chat Front End Server Persistent Chat SIP 5041 TCP (MTLS)
Persistent Chat Front End Server Persistent Chat Windows Communication Foundation (WCF) 881 TCP (TLS) and TCP (MTLS)
Persistent Chat Front End Server Persistent Chat File Transfer Service 443 TCP (TLS)

Note

Some remote call control scenarios require a TCP connection between the Front End Server or Director and the PBX. Although Skype for Business Server no longer uses TCP port 5060, during remote call control deployment you create a trusted server configuration, which associates the RCC Line Server FQDN with the TCP port that the Front End Server or Director will use to connect to the PBX system. For details, see the CsTrustedApplicationComputer cmdlet in the Skype for Business Server Management Shell documentation.

For your pools that use only hardware load balancing (not DNS load balancing), the following table shows the ports that need to open the hardware load balancers.

Hardware Load Balancer Ports if Using Only Hardware Load Balancing

Load Balancer Port Protocol
Front End Server load balancer 5061 TCP (TLS)
Front End Server load balancer 444 HTTPS
Front End Server load balancer 135 DCOM and remote procedure call (RPC)
Front End Server load balancer 80 HTTP
Front End Server load balancer 8080 TCP - Client and device retrieval of root certificate from Front End Server - clients and devices authenticated by NTLM
Front End Server load balancer 443 HTTPS
Front End Server load balancer 4443 HTTPS (from reverse proxy)
Front End Server load balancer 5072 TCP
Front End Server load balancer 5073 TCP
Front End Server load balancer 5075 TCP
Front End Server load balancer 5076 TCP
Front End Server load balancer 5071 TCP
Front End Server load balancer 5080 TCP
Front End Server load balancer 448 TCP
Mediation Server load balancer 5070 TCP
Front End Server load balancer (if the pool also runs Mediation Server) 5070 TCP
Director load balancer 443 HTTPS
Director load balancer 444 HTTPS
Director load balancer 5061 TCP
Director load balancer 4443 HTTPS (from reverse proxy)

Your Front End pools and Director pools that use DNS load balancing also must have a hardware load balancer deployed. The following table shows the ports that need to be open on these hardware load balancers.

Hardware Load Balancer Ports if Using DNS Load Balancing

Load Balancer Port Protocol
Front End Server load balancer 80 HTTP
Front End Server load balancer 443 HTTPS
Front End Server load balancer 8080 TCP - Client and device retrieval of root certificate from Front End Server - clients and devices authenticated by NTLM
Front End Server load balancer 4443 HTTPS (from reverse proxy)
Director load balancer 443 HTTPS
Director load balancer 4443 HTTPS (from reverse proxy)

Required Client Ports

Component Port Protocol Notes
Clients 67/68 DHCP Used by Skype for Business Server to find the Registrar FQDN (that is, if DNS SRV fails and manual settings are not configured).
Clients 443 TCP (TLS) Used for client-to-server SIP traffic for external user access.
Clients 443 TCP (PSOM/TLS) Used for external user access to web conferencing sessions.
Clients 443 TCP (STUN/MSTURN) Used for external user access to A/V sessions and media (TCP)
Clients 3478 UDP (STUN/MSTURN) Used for external user access to A/V sessions and media (UDP)
Clients 5061 TCP (MTLS) Used for client-to-server SIP traffic for external user access.
Clients 6891-6901 TCP Used for file transfer between Skype for Business clients and previous clients.
Clients 1024-65535 * TCP/UDP Audio port range (minimum of 20 ports required)
Clients 1024-65535 * TCP/UDP Video port range (minimum of 20 ports required).
Clients 1024-65535 * TCP Peer-to-peer file transfer (for conferencing file transfer, clients use PSOM).
Clients 1024-65535 * TCP Application sharing.
Aastra 6721ip common area phone
Aastra 6725ip desk phone
HP 4110 IP Phone (common area phone)
HP 4120 IP Phone (desk phone)
Polycom CX500 IP common area phone
Polycom CX600 IP desk phone
Polycom CX700 IP desk phone
Polycom CX3000 IP conference phone
67/68 DHCP Used by the listed devices to find the Skype for Business Server certificate, provisioning FQDN, and Registrar FQDN.

* To configure specific ports for these media types, use the CsConferencingConfiguration cmdlet (ClientMediaPortRangeEnabled, ClientMediaPort, and ClientMediaPortRange parameters).

Note

The setup programs for Skype for Business clients automatically create the required operating-system firewall exceptions on the client computer.

Note

The ports that are used for external user access are required for any scenario in which the client must traverse the organization's firewall (for example, any external communications or meetings hosted by other organizations).

IPsec exceptions

For enterprise networks where Internet Protocol security (IPsec) (see IETF RFC 4301-4309) has been deployed, IPsec must be disabled over the range of ports used for the delivery of audio, video, and panoramic video. The recommendation is motivated by the need to avoid any delay in the allocation of media ports due to IPsec negotiation.

The following table explains the recommended IPsec exception settings.

Recommended IPsec Exceptions

Rule name Source IP Destination IP Protocol Source port Destination port Authentication Requirement
A/V Edge Server Internal Inbound Any A/V Edge Server Internal UDP and TCP Any Any Don't authenticate
A/V Edge Server External Inbound Any A/V Edge Server External UDP and TCP Any Any Don't authenticate
A/V Edge Server Internal Outbound A/V Edge Server Internal Any UDP & TCP Any Any Don't authenticate
A/V Edge Server External Outbound A/V Edge Server External Any UDP and TCP Any Any Don't authenticate
Mediation Server Inbound Any Mediation
Server(s)
UDP and TCP Any Any Don't authenticate
Mediation Server Outbound Mediation
Server(s)
Any UDP and TCP Any Any Don't authenticate
Conferencing Attendant Inbound Any Front End Server running Conferencing Attendant UDP and TCP Any Any Don't authenticate
Conferencing Attendant Outbound Front End Server running Conferencing Attendant Any UDP and TCP Any Any Don't authenticate
A/V Conferencing Inbound Any Front End Servers UDP and TCP Any Any Don't authenticate
A/V Conferencing Outbound Front End Servers Any UDP and TCP Any Any Don't authenticate
Exchange Inbound Any Exchange Unified Messaging UDP and TCP Any Any Don't authenticate
Application Sharing Servers Inbound Any Application Sharing Servers TCP Any Any Don't authenticate
Application Sharing Server Outbound Application Sharing Servers Any TCP Any Any Don't authenticate
Exchange Outbound Exchange Unified Messaging Any UDP and TCP Any Any Don't authenticate
Clients Any Any UDP Specified media port range Any Don't authenticate