DNS records and firewalls for Pexip Windows app connectivity

To ensure that Pexip apps can successfully locate and connect to Pexip Infinity you must set up appropriate DNS records and ensure your firewalls are configured correctly.

DNS records

You must set up DNS records so that the Pexip app knows which host to contact when placing calls or registering to Pexip Infinity.

The host will typically be a public-facing Conferencing Node (for on-premises deployments where your Transcoding Conferencing Nodes are located within a private network we recommend that you deploy public-facing Proxying Edge Nodes).

To enable access from the Pexip app, each domain used in aliases in your deployment must either have a DNS SRV record for _pexapp._tcp.<domain>, or resolve directly to the IP address of a public-facing Conferencing Node.

The SRV records for _pexapp._tcp.<domain> should always:

  • point to an FQDN which must be valid for the TLS certificate on the target Conferencing Nodes
  • point to an A/AAAA record
  • reference port 443 on the host.

The Pexip app for Windows does not perform a DNS lookup when placing a call, because its outbound calls are always routed via the Conferencing Node to which it is registered.

Ultimately it is the responsibility of your network administrator to set up SRV records correctly so that the Pexip app knows which system to connect to.

You can use the tool at http://dns.pexip.com to lookup and check SRV records for a domain.

Firewall configuration

Pexip apps connect to a Conferencing Node, so you must ensure that any firewalls between the two permit the following connections:

  • Pexip app (all clients) > Conferencing Node ports 40000–49999 TCP/UDP
  • Conferencing Node ports 40000–49999 TCP/UDP > Pexip app (all clients)

For more information, see Pexip Infinity port usage and firewall guidance.

Using Pexip apps from outside your network

In many cases, your Pexip Infinity deployment will be located inside a private network. If this is the case and you want to allow Pexip app users who are located outside your network (for example on another organization's network, from their home network, or the public internet) to connect to your deployment, you need to provide a way for those users to access the private nodes and to switch between private and external networks.

Since version 16 of Pexip Infinity, we recommend that you deploy Proxying Edge Nodes instead of a reverse proxy and TURN server if you want to allow externally-located clients to communicate with internally-located Conferencing Nodes. A Proxying Edge Node handles all media and signaling connections with an endpoint or external device, but does not host any conferences — instead it forwards the media on to a Transcoding Conferencing Node for processing.

Connectivity example

Assume that the following _pexapp._tcp.vc.example.com DNS SRV records have been created:

_pexapp._tcp.vc.example.com. 86400 IN SRV 10 100 443 px01.vc.example.com.
_pexapp._tcp.vc.example.com. 86400 IN SRV 20 100 443 px02.vc.example.com.

These point to the DNS A‑records px01.vc.example.com, port 443 (HTTPS), with a priority of 10 and a weight of 100, and px02.vc.example.com, port 443, with a relatively lower priority of 20 and a weight of 100.

This tells the Pexip apps to initially send their HTTP requests to host px01.vc.example.com (our primary node) on TCP port 443. The Pexip apps will also try to use host px02.vc.example.com (our fallback node) if they cannot contact px01.