I’m not sure what you mean by the “(AT” — do you mean: - AT commands (the Hayes-style AT command set for modems), or - AT&T (an AT&T‑branded unit / ISP configuration), or - something else (setup, reset, firmware, bridging, PPPoE, troubleshooting)? Tell me which of those (or give more detail) and I’ll give step‑by‑step instructions. If helpful, here are a few quick pointers I can expand on: - Access the router web UI: typically via its LAN IP (common ones are 192.168.1.1 or 192.168.0.1). - Factory reset: press and hold the small Reset button on the unit for ~10 seconds (power on) to restore defaults. - PPPoE/ADSL setup: set encapsulation to PPPoE or PPPoA and enter your ISP username/password; VPI/VCI values depend on your ISP. - Bridging mode: many SpeedStream 5100 variants support bridge vs. router mode in the web UI. - AT commands: consumer ADSL routers often do not expose a full modem AT command console; some require a serial connection and special drivers/firmware if available. - Firmware: ISP‑branded units may be locked; check Siemens/SpeedStream or your ISP support site for updates. Which do you want to do?

The SpeedStream 5100 (AT&T) is a router manufactured by the company Siemens that allows multiple devices to connect to a network and communicate with each other. It works by receiving data packets from devices and forwarding them to their intended destination. The router is assigned a unique IP address 192.168.0.1, which serves as its identifier on the network.

To access the router's settings and configure its functions, users can log in using a web browser and their and admin. Once logged in, users can customize various settings such as network name, password, and security protocols. They can also set up parental controls, prioritize bandwidth usage, and monitor network activity.