Visitor
•
3 Messages
Bufferbloat C grade - is AQM enabled? And dropped network frames when Twitch streaming
A little bit of background:
I've been streaming on Twitch for many years, with no issues with dropped network frames, but for some reason have started seeing quite a bit during Twitch streaming in the past few months.
I ran several Bufferbloat tests and they call come back with a grade of C. I did some research and this seems to mean the issue is with the router. I checked and found that my Xfinity modem was outdated and due for an upgrade to get the best speeds (I'm on the 2 GB plan), and now I have the XB8. I'm still getting dropped frames during streaming and the Bufferbloat test still gives a grade of C.
Further research shows that having a router with either SQM or AQM can help with this. I checked and see that the XB8 modem should have AQM (Advanced Queue Management). I remoted in to the router's settings and don't see this setting anywhere - how can I verify this is enabled? Further, I read that this can not only be a router setting, but that AQM has to be "enabled in the area" - how do I find this out?
I tried calling - I couldn't get past the useless automated system to talk to a real person.
I tried the so-called Xfinity assistant - again, useless
I tried checking the 'submit a ticket' - which only lets you submit a ticket for 3 completely unrelated things - again, useless
So far this has been some of the most frustrating, maddening support experiences I have had with any company. I'd switch if I could.
Accepted Solution
XfinitySara
Official Employee
•
2.4K Messages
3 hours ago
Hello, @nightwriter2000! I hear your frustration loud and clear. Dealing with a "C" grade in bufferbloat when you’re paying for a 2 Gbps plan is like owning a Ferrari but being stuck in a school zone. It can be especially maddening when you're a streamer, as dropped frames are the fastest way to lose an audience. Let’s look at what’s actually happening under the hood of that XB8.
Is AQM Enabled on the XB8?
Here is the short answer: The XB8 does have AQM (specifically using the DOCSIS 3.1 "PIE" algorithm), but it is usually "hard-coded."
- The Setting: As our Expert (EG) mentioned, we typically do not give users a toggle switch for AQM/SQM in the gateway's firmware. We manage it via the CMTS (the equipment at the local office).
- "Enabled in the Area": This refers to our rollout of "Full Duplex" or "Enhanced Speed" markets. In these areas, we updated the CMTS to better handle congestion. If your upload speeds recently jumped (e.g., from 35 Mbps to 200+ Mbps), you are likely in an "enhanced" area where AQM is active on our end.
Why the "C" Grade and Dropped Frames Persist
Even with AQM active, a "C" grade means your data packets are still getting stuck in a "buffer" (a digital waiting room) when your bandwidth is maxed out. Since Twitch streaming requires a consistent, steady heartbeat of data, any delay (latency spikes) causes the Twitch server to drop those late packets, resulting in dropped network frames.
Troubleshooting the "Last Mile"
Since the XB8 isn't solving it, the bottleneck is likely in one of three places:
1. The "Puma 7" Chipset Issue: While the XB8 is better than older models, Intel-based Puma chipsets have a history of jitter and latency spikes. Most pro streamers bypass this by putting the Xfinity Gateway into Bridge Mode and using a high-end third-party router with SQM (Smart Queue Management) like Cake or FQ_CoDEL.
2. The Upload Ceiling: If you are streaming at a high bitrate (6000+ kbps) but your "Enhanced" upload isn't active yet, you might be hitting the 35 Mbps upload cap. Even small background tasks (Cloud backups, phone photo syncing) can choke that 35 Mbps pipe, causing bufferbloat.
3. Local Node Congestion: If this started recently, there could be "noise" on your neighborhood's physical line. Since the automated system is blocking you, try using the Xfinity App to "Test my speed to the gateway." If the speed to the gateway is lower than your plan, it forces the system to let you schedule a tech.
What to try next
Before you spend more money on hardware, try these two "free" steps:
- Cap your Upload: In OBS/Streamlabs, ensure you aren't pushing more than 75% of your total upload capacity.
- Check for "Network Optimizers": If you have a "Gaming" motherboard, disable software like Killer Networking or ROG GameFirst. These often conflict with Windows' own packet handling and cause the exact dropped frames you're seeing.
And please let me know if any of this helps! We remain here to take a closer look and/or schedule a Trouble Call (tech visit) if necessary.
4
EG
Expert
•
116.4K Messages
2 days ago
FWIW, the Xfinity rented gateway devices do not offer any toggleable or adjustable AQM / QoS settings.
(edited)
0
0