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ANSWERED: How to Self Install and Activate Your Comcast Wireless Gateway

For best WiFi coverage, try to place your wireless gateway close to where you most frequently use your WiFi-capable devices. For best WiFi reception and minimal interference, place your wireless gateway in an open area away from items such as exterior walls, metal surfaces, microwaves and windows. Once you’ve ensured the Comcast wireless gateway is in the best location in your home, it’s time to plug it in and power it up.

Note: If you are replacing a modem currently connected in your home, be sure to unplug that device from the cable or coaxial outlet and plug the new modem into that same outlet. If you do not have an existing modem set up, simply plug your new modem into the main cable or coaxial outlet in your home.



Once you set up your network, you can wirelessly access the Internet and other XFINITY services from your computer, laptop, game system and more. Your wireless gateway or wireless router makes it easy to set up your network and adjust your settings. Before you begin, you can find out more information about wireless networking at What is Home Networking?, or you can find out how to set up a wireless network with these simple steps.

These steps are specific to customers with the following equipment:
  • Wireless Gateway 1 (model numbers TG852G, TG862G, SMCD3DNV, or TC8305C)
  • Wireless Gateway 2 (model number DPC3939)
  • Wireless Gateway 3 (model numbers DPC3941T and TC8717)
  • Other routers may have some variations


Connect Your Wireless Gateway

Before you can access XFINITY services or the Internet through your wireless gateway, you'll need to make sure it's properly connected. Please check that:
  1. Your wireless gateway is connected to the Internet through the Cable connector on the back panel with a coaxial cable.
    Back panel of a wireless gateway.  Options are listed below.
Wireless gateway back panel features are:
  • Reset button for resetting the wireless gateway
  • USB host connector [for future use]
  • Tel1 connector for analog phone line
  • Tel2 connector for analog phone line
  • Gigabit Ethernet (1-4) connectors for use with a computer LAN port
  • Cable connector for the coaxial cable
  • Power connector for the power cord
  1. Your wireless gateway is plugged into a power source through the Power connector with the provided power cord.
  2. The Power, US/DS, and Online LED indicators on the front panel are steadily lit. This may take several minutes after plugging in your wireless gateway.
    Wireless gateway - front of device, displaying LED lights (and other indicators).


How To Self-Install Internet


How To Self-Install Internet & Voice

Now you are ready to activate your Comcast services and your wireless gateway.

Activating Your Wireless Gateway

Once you've installed your Wireless Gateway device and established a temporary Internet connection, you're ready to activate your XFINITY Internet/Voice service. See information about preparing to activate your Wireless Gateway.

This article outlines the on-screen instructions to complete the activation of your Gateway.

If you're activating an XFINITY xFi Gateway (models Arris 1682G, Cisco 3941T or Arris TG3482G), see Activating Your XFINITY xFi Gateway. To determine the type of gateway you have, check the make and model information located on the bottom of your device. You can also check this information in My Account.


Activation Instructions

Once connected to the Internet, if you're not automatically presented with an Activation Welcome screen:
  1. Open a web browser (such as Chrome, Safari, Internet Explorer, etc.) on your device and go to Click Continue.
    Welcome to XFINITY Activation screen.
  2. Enter your XFINITY account number and phone number (If you received a Self Installation Kit, your account number can be found on the Activation Information card inside the kit.). You can also authenticate your account by signing in with your XFINITY username. If you've already created a username, click on Sign in here and skip steps 3 through 5 below.
    Authentication screen requests account number and phone number.
  3. Create an XFINITY username and password. If you have moved and are transferring your XFINITY service(s) to a new address, click Sign in with your existing username.
  4. Choose a security question and answer (answer must be 3-25 characters long and is case-sensitive), and check the box that you agree to the Terms and Privacy policy, then click Continue.
    • Note: Your XFINITY username provides access to your account settings and XFINITY services. It will also become your email address prefix, as in [Username] Feel free to use it as your primary email account or as a spare. We recommend writing down this important information.
      Screen for entering your XFINITY username, password, security question and answer.
  5. Click Continue to proceed from the Connection Established screen.
    Screen confirms that connection has been established.
  6. After you receive the Device Activated screen, your gateway may reboot. It should be all set when the Power, US/DS and Online lights on the front of your gateway stop blinking and remain solid for one minute, and the WiFi light(s) start flashing.
    Activation confirmation screen.
  • You can continue to use the WiFi network name and password on your device, but we recommend that you change your name and password to something easy to remember.
  • Depending on the type of gateway you have, you may be required to create a new WiFi network name and password as part of the activation process.


Need Additional Help?

If you're having trouble activating your gateway or XFINITY services, please call 1-855-OK-BEGIN (1-855-652-3446). For more information about XFINITY Internet, visit
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Last update:
‎01-16-2018 01:17 PM
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