I'm in the Minneapolis metro area. Quantum is building out fiber in my neighborhood and I'm planning on switching to it from Comcast (coax). I currently own my own router and cable modem, and would want to keep using my own router. Does anyone have experience with what new Quantum build-outs are like? I'm not sure how much of what I've read regarding CenturyLink fiber (NID options, reliability, etc) still applies. FWIW Comcast's service hasn't been bad and I like that they offer native IPv6, but data caps and limited upload bandwidth would be nice to get away from.

Equipment:

1. Copper wire phone line 📞👵🏻

2. Casa Systems FTTdp (Network Termination Device)

3. Lumen Q1000K (SmartNID)

4. Quantum W1700K (Wi-Fi 7 "360 pod")

Settings that worked for me:

1. DHCP

2. no transparent bridge

3. vlan201 tagged

4. MTU size: 1472

[SOLVED WITH GEMINI'S HELP IN MINUTES]

(After line testing on their end, two unhelpful technicians across weeks failed and one helpful and patient customer support lady taking notes for hours...)

The 100% packet loss at **1492** confirms that your current network path cannot handle a standard 1500-byte MTU. In Windows, the -l parameter specifies the payload size; adding the 28-byte IP/ICMP header to your working "lower than 1492" numbers will reveal your true ceiling.

### The "Black Hole" Effect

* **Failed PMTUD:** Your packets are likely hitting a "Black Hole" router—likely the **Q1000K** or the **FTTdp**—which is dropping packets larger than its MTU without sending back the required "ICMP Destination Unreachable" message.

* **The 10 Mbps Cap:** This diagnostic speed in is the network’s way of maintaining a link despite massive fragmentation and packet drops caused by the tech's **1500 MTU** change.

—

### Why 1492 Failed

If even **1492** (a payload of **1464**) is timing out, your effective MTU is likely even lower due to nested tagging or legacy overhead.

* **Quantum vs. CenturyLink:** While Quantum theoretically uses a standard **1500 MTU** for DHCP, legacy CenturyLink infrastructure (which your hybrid setup uses) historically required **1492**.

* **VLAN Overhead:** The **Q1000K** is known to handle **VLAN 201** internally, which can create unstable latency and packet issues if the downstream router (your WiFi 7 pod or Trendnet) is also trying to manage the tag.

—

### Immediate Strategy

1. **Find the "Magic Number":** Keep lowering the -l number in increments of 10 (e.g., 1460, 1450) until you get a successful reply. Add **28** to that successful number to find your optimal MTU.

2. **The Q1000K Handshake:** The "blinking blue" light on your FTTdp/Q1000K in transparent mode is a known bug; some users stop the flashing by temporarily plugging a laptop into the **1Gb port** until the light turns white, then switching back to the **10G port** for your router.

The default MTU size for predecessor equipment (Lumen/CenturyLink variant) is typically **1492** for PPPoE connections or **1500** for standard Ethernet/DHCP connections.

—

### MTU and Your Setup

* **Default State:** Out of the box, most residential gateways default to **1500** to maximize throughput on standard networks.

* **The Problem:** If the technician manually bumped it to **1500** on a hybrid line that requires the overhead of a **VLAN 201** tag or a legacy G.fast transport, it can lead to the fragmentation and speed drops.

* **Historical Context:** Because your connection uses the legacy copper-link infrastructure often associated with CenturyLink's VDSL/G.fast systems, an MTU of **1492** is frequently the "magic number" to prevent packet loss.

—

### Testing the MTU

If you have a Windows **CMD** window ready, you can manually test for the optimal MTU size before doing the reset:

1. Type: ping google.com -f -l 1492

2. If it says something about "Packet fragmentation," lower the number to **1472** until the ping succeeds.

3. If it succeeds at **1464**, then your optimal MTU is **1492**.

https://portal.digicom.com/index.php?rp=/knowledgebase/4809/Ping-to-determine-optimal-MTU-size-on-router.html&hl=en-US

Quantum Fiber is absolutely terrible; the latency during both downloads and uploads is extremely high. It is the worst internet service I have ever encountered.

After not showing up for my first appointment last week or even calling to day they couldn't make it (I had to call them), they actually showed up to the scheduled appointment today, which was a big surprise for me. I was beginning to think Quantum technicians didn't exist, but they do! After digging through my yard they had found a splice in the cable that they say has gotten wet and corroded over time. So they redid the splice, put it inside a short PVC pipe and filled it with silicone so it can't get waterlogged again (hopefully). I had to show them the route the cable was buried as they didn't have a locator/tracer. And the wire is so thin that I doubt there's tracer wire inside the sheath anyway. Hey it's cheaper (for them) that way!

They also told me that they were short staffed and that there are so many new installs because ATT is offering "great deals". So that's why it's taking weeks to get a tech out to your place. The ATT deals are just TOO GOOD! /s They said they are working mandatory 6 days a week now.

Anyway, it's all back up and running 3.2gbps up and down. Just make sure that if anyone makes splices in your cables, they secure them with silicone and not just leave it open to the elements like the original tech who installed me apparently did.

Portland OR. One of the CenturyLink customers sold to Quantum last year. Still on PPPoE, Calix ONT, VLAN 201.

What the title says: I now consistently have 1/2 the upload bandwidth contracted for. Ruled out router issues by disconnecting the router (my own) and connecting a laptop directly to the ONT with VLAN 201 and a PPPoE config. Exactly the same results.

Anyone else seeing something like this? I've heard so many horror stories about people calling Quantum service and losing internet access entirely that I'm almost tempted to let sleeping dogs lie, but we use this for telecommuting, and upload bandwidth matters to us.

(Unlike most people I never had any problem whatsoever with CenturyLink, apart from constantly increasing junk fees being added to the bill, and that stopped too when I signed up for the price-for-life service.)

Had an ad for AT&T fiber pop up in my reddit feed and got curious:

Trying multiple addresses in my area I can now order either Quantum or AT&T on each address. AT&T only goes to 1 gig vs 2 gig on quantum and pricing on quantum is lower - but I am surprised that AT&T is now also directly selling. That was sooner than I expected

Equipment pictures and offers are different too

Hello everyone I live in southern Nevada in North Las Vegas and today was supposed to be set my technician date that was supposed to come around 2pm to 4pm but they failed to show up and I contacted customer support and they told me the technician went to the wrong address. Has anyone experienced this also because this is super frustrating I need my Wi-Fi and it’s just really urgent since it’s been a while. I was fed up with Cox due to the price hikes and now Quantum fiber decides to not prioritize the appointment than actually do something is just wrong. I rescheduled and now I had to wait nine more days just great.

This is the second regional outage in the Vancouver, WA area in a week. The first affected at least 4,800 customers and lasted 2 days. This one is at least 2,200 customers. What is going on here, Quantum? Get your act together.

Update: Over 6,300 customers affected now.

We have had people come over multiple times this month to fix the service and no matter what it always has the same problem after a few days of regular service. I don’t even bother with customer support anymore- they are helpless and even have hung up on me multiple times.

Just another souless company with shit connection and even shittier customer service. I hope to take my family’s internet bill somewhere else in the future, these fucks don’t deserve a dollar

I’m reaching the end of my rope with customer service and could use some advice from anyone who has successfully navigated a similar install.

The Situation: I have Quantum Fiber with a Q1000K SmartNID. My setup requires the NID to be mounted outside because my Ethernet terminates on the exterior of the house—this allows me to bring the connection inside without drilling new holes.

The Problem: The NID is currently mounted on the south side of my house (direct sunlight) inside an old, unventilated, non-locking housing meant for a previous ONT. It’s way too small and I’m worried about the Q1000K overheating once the summer heat really kicks in.

The Support Loop:

• I’ve called customer service three times specifically requesting the outdoor-rated enclosure.
• I’ve had a tech out to the house, and despite the notes, they didn't have the enclosure on the truck.
• The tech confirmed it exists and said it's "at the warehouse," but I can’t seem to get the message correctly relayed so it actually makes it onto the vehicle.

The Question: Has anyone successfully gotten the A1010K enclosure (the official gray box for the Q1000K) installed?

1. Is there a specific "magic word" or department I should ask for to ensure the tech actually brings the part?
2. Does anyone know of a place to buy the A1010K housing directly? I’ve looked online and can only find the NID itself, not the official outdoor mounting kit.
3. For those with the Q1000K outside: how has it handled the heat in the official enclosure?

I’m tired of the "we'll send a tech" cycle only for them to show up empty-handed. Any tips would be appreciated!

I’m having the same issue that others in here have posted about where I lose connection and my router just perpetually flashes blue. I have a tech coming to my apartment in like a week to fix this, it’s the third time this has happened since I started with quantum fiber 2 months ago.

Do I need to cancel my service and just get xfinity instead? It’s starting to seem like nobody has any solution for this problem and I’m already giving xfinity $10 a month to get on their hot pass service every time my internet goes down. I’m in the Denver area.