SFR Speed Test
This diagnostic utility validates the throughput of your SFR connection. To interpret your results, you must first distinguish your physical technology. SFR Fibre (FTTH) uses a small optical cable plugged into the wall and offers high uploads (up to 1 Gbps). SFR THD (Coax) uses a round, screw-on cable (same as cable TV) and suffers from "Node Congestion" in the evening.
Understanding Your Speed Metrics
When analyzing your connection integrity, focus on these three performance vectors:
Download Throughput:
• Box 8X (Premium): Wired speeds should hit ~8000 Mbps (8 Gbps) if using the 10G port. On standard ports, it caps at 940 Mbps.
• Box 7 / Box 8 (Power): Wired speeds are "Shared". You have 2 Gbps total capacity, but each Ethernet port is limited to 1 Gbps. You cannot download a single file faster than 1 Gbps.
• THD (Coax): Highly variable. If you pay for 1 Gbps but get 400 Mbps at 9 PM, your neighborhood node is saturated.
Upload Throughput: This instantly identifies if you have "Real Fiber" or "Fake Fiber" (Coax).
• FTTH (Box 7/8/8X): High upload (~500 Mbps to 1 Gbps).
• THD (Coax): Capped upload. Usually 40 Mbps, 60 Mbps, or 100 Mbps. If you are a Youtuber or work from home, this is a major bottleneck.
Latency (Ping): SFR FTTH routes efficiently via Paris (Interxion). Expect 3ms to 10ms. SFR THD (Coax) is slower, typically 15ms to 25ms, and suffers from "Jitter" during peak TV viewing hours.
What Results Should You Expect?
The "Connect TV" Bandwidth Tax
SFR's TV decoders (Connect TV) run on Android TV and use OTT (Over-the-Top) streams. Benchmarks include:
Connect TV Active: Watching a 4K channel (e.g., Canal+ UHD) consumes ~25 Mbps. If you run a speed test while the TV is on, your result will be lower.
Box 8 (Wi-Fi 6): Capable of ~800-900 Mbps wirelessly on modern phones.
Box 7 (Wi-Fi 5): The entry-level box. Wireless speeds physically cap at ~450 Mbps. Do not blame the fiber line; the router's Wi-Fi chip is the limit.
Why Is Your SFR Connection Slow?
Before calling 1023, verify these common configuration faults:
The "Eco" Button: Many SFR boxes have an "Eco" mode that throttles the LAN ports to 100 Mbps to save power. Log into the interface (`192.168.1.1`) and ensure LAN ports are set to "Gigabit" or "Full Power".
Coax Signal Leak (THD Users): If you are on Coax, ensure the white cable is screwed in tight with a wrench. A loose cable lets 4G signals leak into the wire, destroying your internet speed.
CGNAT Issues: SFR has begun migrating IPv4 users to CGNAT. This breaks port forwarding for gamers. You can request a "Rollback to IPv4 Full Stack" via customer support to fix "Strict NAT" in games.
SFR Technical Configuration Data
| Parameter | Configuration Details |
| Router Hardware | Box 8X (XGS-PON) / Box 8 (GPON) / Box 7 / Box THD 4K |
| Gateway IP | 192.168.1.1 (or 192.168.0.1 for older THD) |
| Admin Login | Press the WPS Button on the front to authenticate |
| Critical Light | PON/S (Stable = Good) / LOS (Red = Cut Line) |
| Support Number | 1023 |
How to Get an Accurate Test
Wireless testing on the Box 7 is invalid for Gigabit plans.
To confirm the actual speed delivered to your home:
1. Turn off the Connect TV decoder.
2. Connect a Cat6 Ethernet cable directly to LAN 1.
3. (For Box 8X Users): Ensure you are using the 10G Cage if testing >1 Gbps.
4. Run the test.
If wired speed is low but upload is high, check your computer's antivirus software, which often slows down high-speed downloads.
When to Call Support
Escalate the issue to SFR if you observe these specific failures:
Blinking Green "S": The box is trying to synchronize but failing. (Fiber issue).
Red "LOS" Light: Loss of Signal. The fiber in the street has been unplugged or cut.
Error C1 (THD): The Coax modem cannot register with the headend. Usually a neighborhood outage.
You can manage your network, change Wi-Fi channels, and run self-diagnostics via the SFR & Moi App or by calling 1023.