This section describes using Connectivity Check to check connectivity for interfacing with Microsoft Teams Direct Routing.

Running Connectivity Check

To check connectivity required for services and ports used with Teams, complete the following steps:

  1. In the WebUI, click the Diagnostics tab.
  2. In the left navigation pane, click Teams Direct Routing > Connectivity Check.

  3. Specify the values for each field for the service for which you need to verify port readiness. For SIP/TLS (TCP), the primary and secondary server IP addresses are hard-coded (not editable).
  4. Click Apply. Service connectivity is checked and the Connectivity Check results display.


    For example, after connectivity is checked for DNS (TCP), the message:  "DNS TCP check on <ip address>: Port (<ip address:port number>) is open" displays in the Connectivity Check Results. A second result using the same format displays the results for the Secondary Server specified. For more information, refer to Connectivity_Check_Results


  5. Repeat Steps 3 and 4 for each service that requires verification of port readiness.


Connectivity Checks - Field Definitions

Specify the values for fields to specify the services for which Connectivity Check will verify port readiness.

Server Type

The Service for which connectivity requires checking. Valid options: DNS (UDP)DNS (TCP)NTP (UDP); and SIP (TCP).

Destination

The FQDN that is the destination for a service. The Destination field displays only for DNS Service Types.

Primary Server

IP address of the primary server used with a service.

Secondary Server

IP address of the secondary server used with a service. 

Third Server

IP address of the third server used with a service; the Third Server field displays only for SIP (TCP). 

Destination Port

Port used to access the service's destination

Connectivity Check - Results

The following table describes the services for which Connectivity Check verifies port readiness and the format for results.



Connectivity Check Results

Service and ProtocolPortTeams
Direct
Routing
DescriptionConnectivity Check Results
Inbound
SIP/MTLS (TCP)5061
Handles signaling for voice communications
STUN (TCP)443
STUN/TURN negotiation of candidates
STUN (UDP)3478
Determines the version of the Edge Server with which the
Skype server is communicating

SIP/TLS (TCP)5061
(tick)
Handles signaling for voice communications; primary and secondary server IP addresses are hard-coded.
RTP (UDP)16384 - 17584

(tick)

Handles media for voice communications
Outbound
DNS (UDP/TCP)53
(tick)

For the service that resolves the Public FQDN for the Microsoft Signaling Server, the Connectivity Check populates a default destination from the Host Name and Domain Name attributes in Host Information (that is, Web UI's Settings > System > Node-Level Settings). The tool opens the UDP socket and sends a homemade DNS packet.

If the remote server responds with a DNS response packet the port is reported as open. Otherwise, the port is reported as closed.
NTP (UDP)123
(tick)
Service to support timestamps in certificate usage
HTTP (TCP)80

Certificate revocation check and Certificate Revocation
List (CRL) retrieval

The host field is filled by default with the FQDN found in the SBC certificate, under the attribute: CRL Distribution Point.


RTP (UDP)49152-65535
(tick)
Handles media for voice communications
SIP/TLS (TCP)5061
(tick)

Handles signaling for voice communications; primary and secondary server IP addresses are hard-coded.


For Teams Direct Routing, the SIP target can be the Microsoft SIP signaling server; Connectivity Check routes to: sip.pstnhub.microsoft.comsip2.pstnhub.microsoft.comsip3.pstnhub.microsoft.com.


STUN (TCP)443
For the service handling STUN/TURN negotiation of candidates, the Connectivity Check opens a UDP socket and sends a homemade STUN packet.If the remote server does not respond with a STUN error packet, the port is reported as closed. The remote peer is the Microsoft Cloud Edge Server and the STUN protocol determines the Public IP address.
STUN (UDP)3748

For the STUN service that determines the version of the Edge Server with which the Skype server is communicating, Connectivity Check populates a default destination from from the Host Name and Domain Name attributes in Host Information (that is, Web UI's Settings > System > Node-Level Settings). The tool opens the UDP socket and sends a homemade DNS packet.

If the remote server responds with a DNS response packet the port is reported as open. Otherwise the port is reported as closed.
SIP/MTLS (TCP)5061

Service to resolve Microsoft Signaling Server Public FQDN