Is Network Quality of Service - QoS Required for PCoIP protocol deployments?
Since PCoIP is a real-time protocol, quality of service (QoS) must be implemented for virtual desktop or remote workstation deployments using the PCoIP protocol in constrained environments.
Teradici previously recommended QoS as essential for successful deployment in both LAN and WAN network environments since TCP receives preferred handling vs UDP protocol by default in network devices such as switches and routers. Any change in TCP based traffic can result in degraded performance for virtual desktops or remote workstations.
With modern wired networks commonly using 1 gigabit connections to the PCoIP Client and multiple 10 gigabit or faster backbone connections on the LAN, QoS on the LAN may not always be necessary. But, if your PCoIP solution uses a LAN with congestion or must use Wi-FI for PCoIP delivery on the corporate network, investigate implementing QoS on the enterprise Wi-Fi equipment to improve PCoIP session. On a WAN connection, most are typically limited bandwidth and have multiple applications using the bandwidth.
The following image is a netflow graph sampled from a Cisco router. The Cisco router network interface was limited to 30mb, simulating the limit of a WAN connection, and then various traffic and QoS settings were applied. There are 3 PCoIP Sessions playing back video. This is the traffic in red, green and blue. The other traffic are TCP data streams trying to send as much data as possible. The QoS of service applied are:
- None - This is the Cisco router default traffic priorities
- Basic QoS - The Cisco router was set to guarantee 60% of the bandwidth for PCoIP
- Network Based Application Recognition 2 (NBAR2) to classify traffic then QoS rules applied. This setting had different bandwidth guarantees for each PCoIP Session. The settings were approximately Red - 30%, Green, 20 %, Blue 5% of total bandwidth.
| Time | Non PCoIP Traffic | QoS status |
|---|---|---|
| 10:06 - 1:14 | Multiple TCP sessions running as fast as possible. | NBAR2 |
| 10:14 - 10:15 | Multiple TCP sessions running as fast as possible. | None |
| 10:15 - 10:16 | None | None |
| 10:16 - 10:18 | 1 TCP session | None |
| 10:18 - 10:18:30 | None | Basic QoS |
| 10:18:30 - 10:20 | 1 TCP session | Basic QoS |
| 10:20 - End | 1 TCP session | NBAR2 |
As you can see in the graph. On a constrained WAN, one TCP file copy or print job is enough to cause severe interruption to any users on a WAN. This is why Teradici Recommends that all WAN routers on constrained links have basic quality of service applied to increase the priority of PCoIP network traffic.
PCoIP traffic should be set to a QoS priority below Voice-over-IP (VOIP) traffic (if used), but above the priority level for any TCP traffic. For most networks, this translates to a DSCP value of AF41 or AF31 (if interactive video is prioritized above PCoIP traffic).
For more information see:
Network session checklist for PCoIP protocol LAN and WAN deployments