Xfinity Advanced Gateway (XB7): specs and speed limits
The XB7 is Xfinity's cable modem and Wi-Fi router in one box. It ships as two hardware models, CGM4331COM and TG4482A. The FCC filing used here (FCC ID UIDTG4482) covers only the TG4482A; we found no grant for the CGM4331COM. Sources: Xfinity's gateway guide page and the FCC filing.
Specs
| Spec | Value | Source |
|---|---|---|
| Wi-Fi generation | WiFi 6 | Xfinity |
| Wi-Fi class | not yet sourced | — |
| Bands | Dual-band (2.4 GHz and 5 GHz); no 6 GHz | Xfinity; FCC grant |
| Maximum data throughput (maker claim) | 2.5 Gbps | Xfinity |
| 2.4 GHz streams | not yet sourced | — |
| 5 GHz streams | not yet sourced | — |
| 2.4 GHz channel widths | 20/40 MHz | FCC report p5; FCC grant |
| 5 GHz channel widths | 20/40/80 MHz on the grant comment; the DFS report also lists 160 MHz (see note) | FCC grant; FCC DFS report p10 |
| WAN | not yet sourced | — |
| Gigabit Ethernet ports | 4 | Xfinity |
| Coverage | not yet sourced | — |
| 5 GHz conducted output (combined), 5180–5240 MHz | 0.9977 W (30.0 dBm, computed from W) | FCC grant |
| 5 GHz conducted output (combined), 5260–5320 MHz | 0.2472 W (23.9 dBm, computed from W) | FCC grant |
Antenna gain (FCC filing)
The filing states directional gain only, not per-antenna gain (Airgain PIFA antennas).
| Band | Directional gain (dBi) |
|---|---|
| 2.4 GHz, 2412–2462 MHz | correlated 5.3–5.5 / uncorrelated 1.1–1.6 |
| 5 GHz, 5180–5240 MHz | correlated 5.7 / uncorrelated 2.5 |
| 5 GHz, 5260–5320 MHz | correlated 5.7 / uncorrelated 2.5 |
| 5 GHz, 5500–5720 MHz | correlated 5.6 / uncorrelated 2.0 |
| 5 GHz, 5745–5825 MHz | correlated 6.6 / uncorrelated 1.9 |
Sources: 2.4 GHz report p6, 5 GHz report p7–8.
Note: 5 GHz width conflict
The grant comment names "20, 40 and 80 MHz bandwidth" modes. The DFS test report lists 160 MHz as well. We report both and do not pick one. A 160 MHz link on this unit is unconfirmed.
What this means for speed
- The Ethernet ports are gigabit, so one wired device gets at most about 949 Mb/s of TCP data (computed, RFC 6349 §4.1.1), even though Xfinity lists 2.5 Gbps maximum throughput for the gateway.
- There is no 6 GHz radio.
Sources
- Xfinity broadband gateway user guides: https://www.xfinity.com/support/articles/broadband-gateways-userguides
- FCC grant UIDTG4482 (fccid.io copy): https://fccid.io/UIDTG4482
- FCC test reports, linked above
- RFC 6349 §4.1.1: https://www.rfc-editor.org/rfc/rfc6349.html
UNSOURCED count: 5. (Wi-Fi class, streams (2), WAN, coverage)
No test results are published on this page. SpeedBench has not lab-tested this model.