Note: This article is for the legacy High Performance Relay (v1.0). For the article on updated relay server (v2.0) prerequisites, please reference the documentation here.
The Parsec Relay Server is an on-premises high performance relay (HPR) server, and is part of the Parsec for Teams Enterprise license. It's a solution for when you need more control over your network infrastructure and want to ensure P2P connections will be successful.
This lightweight server program relays many concurrent Parsec sessions through a single IP address / port configuration. It can be used to assist with NAT traversal as either an on-premises relay for large LAN deployments of Parsec, or as a general purpose WAN relay server.
If you'd prefer to avoid the Parsec Relay Server, look into Parsec's networking requirements.
Advantages
Reliability
The HPR server is a lightweight sever program that allows efficient relaying of many simultaneous Parsec connections through a single IP address/port configuration. It can be used to assist with NAT traversal as either an on-premise relay for large LAN deployments of Parsec, or as a general-purpose WAN relay server. The HPR server allows customers to route all Parsec traffic through one public IP address, ensuring P2P connections are successful.
Simplification and security
By relaying packets between clients and hosts, the HPR server removes reliance on UPnP or complex firewall rules that would otherwise be required for P2P connections to be successful. The HPR server is hosted by the customer, always remaining under their control in the location of their choice whether that be in on a physical machine in the office or running as a VM in a public cloud.
While it is up to each customer to decide where to deploy the HPR server, Parsec does recommend deploying it in the DMZ. This offers an additional layer of security protecting machines on your internal network from external access.
Architecture
Note: the above diagram shows a typical Parsec deployment, where the relay server is deployed locally to the hosts. However, it is also possible to have client machines local to the relay server and some hosts located externally. For more information on this other deployment model, please see the "Clients local to HPR servers" section of HPR Deployment Considerations and Options.
Prerequisites
Server machine specs
| Component | Minimum spec |
| CPU | 2 cores |
| RAM | 4 GB |
| NIC | 1 Gbps |
Operating system (Minimum versions)
| Distro | Version |
| Ubuntu | 18.04, 20.04, 22.04 |
| RHEL | 7, 8 |
| CentOS | 7, 8 |
Network and firewall
- Public IP
- Private IP
- NAT public IP and port -> private IP and public listener port
| Source IP | Source port | Destination IP | Destination port | Protocol |
| Parsec client machine/Any | Client start port (Default: Random) | Relay public IP | Relay public listener port (Default: 5000) | UDP |
| Parsec host machine | Parsec host start port (Default: Random) | Relay private IP | Relay private listener port (Default: 4900) | UDP |
| Relay private IP |
Relay private listener port (Default: 4900) & Relay public listener port (Default :5000) |
Parsec host machine | Parsec host start port (Default: Random) | UDP |