US workflow
Before replacing a US ISP router, identify which box is actually replaceable
In the US, the most common mistake is calling every provider device a router. Cable modems, fiber ONTs, integrated gateways and Wi-Fi routers play different roles.
1. Cable modem or fiber ONT?
Xfinity and Spectrum cable service still needs a cable modem. GFiber and Fios use fiber termination equipment that can hand Ethernet to a router.
2. Does the provider require its gateway?
AT&T Fiber's supported own-router path keeps the AT&T gateway and uses IP Passthrough. That is different from a direct Fiber Jack → router GFiber setup.
3. Bridge mode or passthrough?
Xfinity/Rogers-style bridge mode disables the gateway's routing role. AT&T IP Passthrough leaves the gateway active but passes the WAN address to a downstream router.
4. Is the modem customer-owned?
If you own the cable modem, modem approval and activation are separate from router compatibility.
5. Does TV change the answer?
Fios TV and other managed services can require provider-specific equipment even when internet-only service works with a third-party router.
Next step
Evidence
- AT&T — internet equipment and supplied gateway (official ISP)
- AT&T — IP Passthrough / DMZplus configuration (official ISP)
- Xfinity — using your own router (official ISP)
- GFiber — using your own router (official ISP)
- Spectrum — internet self-installation: modem to router (official ISP)
- Verizon Community KB — using your own router with Fios (Verizon-hosted community / secondary)
Page reviewed 28 September 2026 · compatibility dataset snapshot 23 September 2026.