You are disconnecting because the bottleneck is almost certainly not your download speed. Roblox drops connections when a single UDP packet stream stalls for roughly 10 seconds, when Wi-Fi retries or bufferbloat add latency spikes, or when the client's memory or page file runs short. New internet raises bandwidth, not stability, and a PC can be "not full" and still lack contiguous RAM or a healthy page file. Empty browser tabs are irrelevant to a fullscreen game client.
Roblox is unusual among games in how aggressively it treats silence as failure. It runs most real-time traffic over UDP, sends periodic keepalive pings, and severs the session when acknowledgments stop arriving inside a fixed window. That window does not care whether your ISP advertises 1 Gbps or 100 Mbps. It cares whether packets arrive, in order enough to reconstruct state, within a deadline measured in seconds.
This is why a brand-new fiber install can feel worse than the aging cable line it replaced. New infrastructure often ships with new hardware defaults: a combined router-modem with aggressive Wi-Fi power saving, a carrier-grade NAT layer, or IPv6 enabled for the first time. Each of those can introduce a failure mode your old setup never had. The rest of this explainer walks through the actual mechanism, then the edge cases that trip up even careful users, then concrete steps with thresholds you can check.
The UDP keepalive and timeout mechanism
Roblox's client maintains a persistent session with game servers using a RakNet-derived transport, which is a UDP-based protocol layer that handles reliability, ordering, and connection liveness on top of raw datagrams. Unlike TCP, UDP has no built-in notion of a dropped connection. Something has to decide when a peer is gone. That something is an application-level timeout: if the client stops receiving server packets for a set interval, it declares the connection dead and shows the disconnect dialog.
The practical consequence is that brief but total packet loss is more dangerous than sustained slowness. A connection that delivers 95 percent of packets smoothly but drops everything for 11 seconds will disconnect. A connection that delivers 100 percent of packets at 150 ms latency will not, even though it feels worse to play. Roblox's anti-cheat and physics validation also run on tight timing assumptions, so the server may reject a client that resyncs too far out of step.
There is a counterintuitive professional caveat here. Many "fixes" people apply — VPNs, DNS changes, TCP optimizers — do nothing for this layer. DNS resolves the initial server address once; after that, the session rides on raw IP packets. A VPN can help only if your ISP is actively mangling UDP, which is rare on residential connections but common on some mobile and campus networks.
What "new internet" actually changes, and what it does not
A new ISP install typically changes four things: the physical medium, the modem or gateway, the public IP assignment method, and the routing path to Roblox's data centers. It does not change your PC's RAM, your Wi-Fi adapter, your router's firmware, or the number of devices competing for airtime. Those unchanged variables are where most post-install disconnects hide.
Connection stability depends on a chain: Wi-Fi link, router NAT table, modem signal, ISP routing, and the peering path to Roblox's edge. New internet replaces maybe two links in that chain. If the Wi-Fi adapter is a decade-old 802.11n card, or the router is now double-NATing behind the ISP gateway, the weakest link is unchanged or newly created. Bandwidth is the one metric that improved, and bandwidth was almost never the problem for a game that needs well under 1 Mbps of sustained throughput.
Bufferbloat deserves specific mention because new, faster connections often make it worse. When a router's upload buffer fills, latency can balloon from 20 ms to 500 ms or more for every packet in the queue, including game traffic. Speed test sites now report bufferbloat grades; an "F" grade with fast download speed is a classic signature of a connection that will disconnect under load even though it benchmarks well.
Quantified context: thresholds that matter
| Metric | Healthy target | Disconnect risk threshold | Why it matters |
|---|---|---|---|
| Sustained packet loss | Under 1% | Above 2-3% | Keepalives fail silently |
| One-way latency | Under 60 ms | Above 150 ms | Physics and anti-cheat desync |
| Jitter (latency variation) | Under 10 ms | Above 30 ms | Reordering looks like loss |
| Bufferbloat grade | A or B | D or F | Latency spikes under load |
| Free RAM during session | Above 1 GB | Under 300 MB | Client can stall mid-packet |
| Page file free space | Above 10 GB | Under 2 GB | Memory pressure kills the process |
These thresholds are approximate engineering guidance, not official Roblox specifications, because Roblox does not publish its exact timeout constants. The ranges above reflect the behavior of UDP keepalive systems generally and are useful as diagnostic cutoffs rather than guarantees. If your measurements sit well inside the healthy column and you still disconnect, the cause is likely local to the machine, not the network.
Storage works differently than most people assume. A drive with 50 GB free is not "full," yet Windows may still fail to grow the page file if the free space is fragmented or if the page file is capped at a fixed size. Roblox's client can consume 1-3 GB of RAM during a long session, and when physical RAM runs short, Windows pages memory to disk. If that paging stalls, the client misses keepalive deadlines even though the network is perfect.
Edge cases that mimic network problems
The most common misdiagnosis is attributing a memory-driven freeze to the internet. When the Roblox client stalls for several seconds during a garbage collection pause or a page-file write, Windows' networking stack may drop queued packets or the client may simply stop sending acknowledgments. The server sees silence, times out, and disconnects you. On your end it looks like a network drop, which is why replacing the router never fixes it.
A second edge case is the double-NAT and CGNAT problem. Many new fiber and fixed-wireless providers place customers behind carrier-grade NAT, meaning you do not have a public IPv4 address. Some implementations handle UDP mapping poorly and expire the mapping during idle moments or under load. Symmetric NAT, which assigns different external ports per destination, is especially hostile to peer-assisted and UDP-heavy traffic. You can detect CGNAT by comparing your router's WAN IP to the public IP a "what is my IP" site reports; if they differ and your WAN address falls in the 100.64.0.0/10 range, you are behind carrier NAT.
A third edge case is Wi-Fi power saving. Laptops and many desktop Wi-Fi cards enable a power-save mode that batches packets and sleeps the radio between beacons. This is fine for browsing and catastrophic for a game that needs sub-second round trips. The symptom is periodic, rhythmic disconnects roughly every few minutes rather than random ones.
Warning: a VPN that routes through a distant city adds latency and can trigger timeouts. Warning: "gaming mode" router presets sometimes disable the very QoS that prevents bufferbloat. Warning: a new gateway in router mode plus your old router creates double NAT unless one is bridged. Warning: antivirus web shields can inspect and delay UDP traffic in ways that break keepalives. Warning: Wi-Fi extenders and mesh nodes halve throughput per hop and add 20-50 ms of jitter.
Misconceptions about tabs, storage, and speed
The belief that extra browser tabs cause game disconnects is understandable but wrong in the way most people apply it. Tabs consume RAM, and RAM pressure can indirectly cause a freeze that looks like a disconnect. But if you have closed the tabs and still disconnect, the tabs were never the mechanism. The relevant variable is total system memory pressure at the moment of the drop, including the game, the OS, background updaters, and any overlays.
The belief that "not full on storage" means storage is fine is a related error. Robust Performance (a Windows storage health feature) aside, the practical issue is free space for the page file and for temporary shader and asset caches. Roblox streams assets to disk during play; a nearly full drive with fragmented free space can cause multi-second stalls. A drive at 90 percent capacity behaves measurably worse than one at 60 percent, regardless of whether Windows labels it "full."
And the belief that new internet should fix disconnects conflates two different service qualities. Throughput is how much data per second; reliability is how consistently packets arrive. ISPs sell throughput and often advertise reliability, but the two are engineered separately. A connection can pass every speed test and still fail a 30-minute UDP stability test.
A diagnostic and fix sequence with thresholds
Work top-down from measurement to fix, because guessing at fixes wastes time and can introduce new problems. Start by measuring the right things, then change one variable at a time.
Measure packet loss and jitter with a tool that tests UDP specifically, not just ICMP ping, because routers often deprioritize ICMP while forwarding UDP normally. Run the test for at least 10 minutes during the hours you actually play. Record loss percentage, average latency, and jitter against the thresholds in the table above.
Then isolate the local machine. Open Task Manager, play for 20 minutes, and watch the memory graph and the "commit charge" figure. If free physical RAM drops below about 1 GB or the commit charge approaches its limit, you have found a memory bottleneck that a new ISP cannot fix. Check page file settings: ensure it is system-managed or at least 10 GB, and that the drive hosting it has room to grow.
Then isolate the network path. Switch to a wired Ethernet connection for one full session. If disconnects stop, the Wi-Fi link is implicated; if they continue, the problem is upstream or local to the PC. Compare your router's WAN IP to your public IP to rule out CGNAT. If you find CGNAT, ask the ISP whether a public IP is available, sometimes for a small monthly fee.
Finally, address bufferbloat and NAT stacking. Bridge the ISP gateway if you use your own router, or remove the second router. Enable SQM (smart queue management) or a well-configured QoS profile on the router to keep game traffic ahead of bulk downloads. Disable Wi-Fi power saving in the adapter's advanced settings and in Windows power plan. Test after each change, and keep a log of what you changed and what the measurement did.
What you cannot fix from your side
Some disconnect causes live beyond your control, and recognizing them saves you from endless tinkering. Roblox's own server health, regional peering congestion, and anti-cheat false positives can disconnect you regardless of your setup. If disconnects cluster at specific times of day or affect only certain games, the cause is likely server-side or peering-related, not your new internet. ISP routing changes after an install can also route you through a congested exchange for weeks before settling.
The honest limitation is that Roblox publishes few specifics about its timeout constants, transport tuning, and server selection logic. Much of what the community knows comes from observation and from the behavior of the underlying RakNet-style transport, which means exact thresholds are inferred rather than documented. Treat the numbers in this article as diagnostic guides, not official specifications. When measurements are clean and disconnects persist, the correct next step is a support ticket with your measurement logs, not another router reset.