QoS with In-Home Streaming

[hobbz]

I'm playing around with Powerline adapters and the streaming is great. However, just to make sure it stays that way if some other device starts using the network I looked into how Steam implements QoS.

With "Prioritize network traffic" selected in "Advanced Host Options" Steam will add a QoS flag to the UDP packets sent over the network.

Using tcpdump, the UDP packets from my PC (host) going to the SteamOS machine (client) showed a tos setting of 0xa0. This is equivalent to RTP used for Voice-over-IP.

09:50:33.839076 IP (tos 0xa0, ttl 128, id 30685, offset 0, flags [none], proto UDP (17), length 1492)
    10.4.2.2.27031 > 10.4.2.15.42066: UDP, length 1464

So, for the TP-Link Powerline adapters, the "Simple Application Mapping" should be set to "Voice Over IP" and not "Online Gaming."

Most modern routers will have this QoS setting available and probably already turned on. Alternatively, if your router supports it, you could create your own QoS rules matching any packet with a source port of 27031 or 27036 as referenced here: https://support.steampowered.com/kb_article.php?ref=3629-RIAV-1617#networkports

[Taylor]

I know this is an old post but this is very helpful. I'll look to see if it still applies.

[Tiberious_ST]

I'm not entirely clear on this. Using a Netgear R7000 I only enable Downstream QoS? Adding a rule by keyword Steam. No upstream QoS settings? I've never played with QoS so please forgive some ignorance on my part.

Jim

[Duke of Leamington]

Excellent post! Thank you. Is it still valid in 2022? I just switched my powerline adapter to voip.

[_I_]

router qos settings should only apply to wan/internet traffic not lan traffic

make sure windows network is set to private not public
and steam is set to allow direct connections, and all remote play devices are connecting to the same router or lan/subnet
so it does not use steams internet relays

[Duke of Leamington]

Good shout about private network. Of course I had it set to public.

To explain my QoS situation, I’m using powerline between router and streaming PC of bandwidth around 300Mbps. QoS applies to me even locally.