C4000XG modem user guide

C4000 modem front and back views

Features of the C4000XG

  • WiFi 6 technology with dual-band 2.4 GHz and 5 GHz 802.11ax
  • Smart Connect single wireless network (SSID): Auto-selects the fastest band for each device
  • Single status light ring 
  • Dynamic QoS: Prioritizes data through the router for smoother streaming
  • Standards-based WiFi WPA3 security

Speed specifications

This gateway is tested and certified to run up to 940 Mbps on the Quantum Fiber network. 


Note: Speeds reflect the maximum download speed the technology can deliver Quantum Fiber service. In-home speeds may differ based on router setup, devices and other factors. 

Diagram of the C4000XG

C4000XG diagram with front light and rear ports

Top troubleshooting tips

  • Connection issues? Restarting your modem is a good first step to fix many common problems.
  • Tried restarting and still having trouble? Learn more about resetting the modem to its default settings.
  • Need more help? Our troubleshooting team is standing by. Contact us through your Quantum Fiber app, or by signing in to your account.