AT&T U120 User manual

1
AT&T U120 Install Guide
Version D6.0.1

2
© 2023 AT&T Intellectual Property. All rights reserved. AT&T, the AT&T logo and all other AT&T marks
contained herein are trademarks of AT&T Intellectual Property and/or AT&T affiliated companies. All
other marks contained herein are the property of their respective owners.
CALIFORNIA PROPOSITION 65 WARNING
WARNING: Cancer and Reproductive Harm –www.P65Warnings.ca.gov

3

רצומב




•
•
•רצומה
•רצומה
•רצומב

•רצומה
•
•

•רצומה


•

•
•
•Class A










ןאוביהלנוישנרטניא ססיורס קרווטנ לבולג יט דנא יט ייא05107 דול ,הפועתה הדש תיירק ,4 בגנה בוחר

DSA-60PFB-24 1 190250



Class A




4
Table of Contents
Installing the U120.........................................................................................................................................................................................5
Step 1: Establish Connectivity to the Internet.............................................................................................................................................5
Option a. Wired Ethernet Connection.....................................................................................................................................................5
Option b. Cellular Connection................................................................................................................................................................5
Option c. WiFi Connection.....................................................................................................................................................................6
Step 2: Establish Local Network Connectivity ............................................................................................................................................7
Option a. Wired LAN Connection..........................................................................................................................................................7
Option b. WiFi LAN Connection............................................................................................................................................................7
Configuring the U120 Internet Connectivity...............................................................................................................................................8
Access the U120 Web Interface...................................................................................................................................................................8
Primary IPv4 WAN Interface Setup ............................................................................................................................................................9
Configuring DHCP ...............................................................................................................................................................................10
Configuring a Static IP Address............................................................................................................................................................11
Configuring IP Unnumbered.................................................................................................................................................................12
Configuring PPPoE...............................................................................................................................................................................13
Configuring a Cellular Connection.......................................................................................................................................................14
Cellular service verification..................................................................................................................................................................16
WiFi WAN Interface.............................................................................................................................................................................17
Administrator Access.................................................................................................................................................................................20
Establishing VPN Connectivity .................................................................................................................................................................21
Firewall Ports ...........................................................................................................................................................................................24
LAN Port Configuration.............................................................................................................................................................................24
VLANS.......................................................................................................................................................................................................24
WiFi on Local LAN..............................................................................................................................................................................28
AT&T U120 Hardware / Signal Overview ................................................................................................................................................29
Front Panel Indicators, Switches & Slots .................................................................................................................................................29
Special Cases ............................................................................................................................................................................................29
Rear Panel Ports & Connectors................................................................................................................................................................30
Right Side Expansion Slot .........................................................................................................................................................................30

5
Installing the U120
Unpack the U120, the cables, antennas, and the power supply. Connect the antennas and power supply. Make sure the
power switch is in the on position.
Note: In certain regions, antennas and the cellular modem are not included.
Installation steps vary depending on type of Internet connection and type of local network connectivity. See Figure 1: U120
Rear Panel for connectors on the rear panel of the U120.
Figure 1: U120 Rear Panel
Follow the guide below to determine the necessary setup steps for your environment.
Step 1: Establish Connectivity to the Internet
In many cases, a wired Ethernet connection will be provided by your ISP. This type of connection includes DSL, Cable and
Managed Internet Connections. It is also possible to connect to the Internet via high-speed cellular access, in which case
you should proceed to the Configuring a Cellular Connection section in this guide. It is also possible to connect to the
Internet via WiFi, in which case you should proceed to the WiFi WAN Interface
Once an Internet Connection has been established, the U120 will try to retrieve its configuration from the network, and if
successful, may perform an automatic reboot to pick up the new configuration. This should occur within the first 2-3 minutes
after initial power on. Wait for a steady GREEN ONLINE light on the front panel to indicate the U120 is ready for use.
Basic connectivity has devices on the local network connected to the LAN ports on the back of the U120. The broadband
connection is usually established via the WAN1 Ethernet port.
Option a. Wired Ethernet Connection
Use an Ethernet cable to connect your Internet broadband interface device to the Ethernet port labeled WAN1 on the U120.
The U120 should be connected directly to the broadband interface device. The black cable provided inside the U120’s
packing box is an Ethernet cable.
Dynamic Host Control Protocol (DHCP) is the default configuration for Internet IP addressing of the U120 Internet network
interface. If your device automatically obtains an address from your ISP through DHCP, it should auto-configure shortly
after powering up.
If your Broadband Internet Service Provider supplied you with a static IP address or PPPoE account information for use with
your broadband connection, you will need to perform additional configuration of the primary interface through the U120 web
interface in order to establish Internet access and to retrieve the device configuration. See “Configuring a Static IP
Address” or “Configuring PPPoE” later in the guide.
Option b. Cellular Connection
Certain U120's will have an imbedded cell card and SIM already installed. If the device has an imbedded call card and SIM,

6
please work with your AT&T account team to activate the SIM.
The U120 needs basic setup of the cellular modem via the web interface before it can connect to the Internet to retrieve its
configuration. See “Configuring a Cellular Connection”later in the guide. After a cellular connection is set up and
connected the GREEN ONLINE light on the front panel will blink to indicate the U120 is using a cellular connection.
Option c. WiFi Connection
The U120's also can use a WiFi connection for connectivity to the Internet. The U120 needs basic setup of the WiFi
connection before it can connect to the Internet to retrieve its configuration. See WiFi WAN Interface later in this guide
for details.

7
Step 2: Establish Local Network Connectivity
In most cases, your devices will attach directly to the U120 via one of the 8 LAN ports with an Ethernet cable. The LAN
configuration of the U120 is controlled by your IS Department and is not configurable by any user.
Option a. Wired LAN Connection
The default configuration for computers attaching to any of the U120 Local LAN ports is DHCP. If you are not sure if you
are using DHCP for your LAN IP addressing, please contact your Information Services (IS) Department for assistance before
proceeding.
If your computer is configured to use DHCP, but the U120 is not providing your computer with an IP address, please contact
your IS Department. In this case you will not be able to access the web Interface as described below.
Note: After the U120 has retrieved its configuration, the local LAN addresses are likely to change from the default values.
If the IP addressing does change, it may be necessary to reboot or reconfigure your devices attached to the U120 in order
to obtain/assign a valid IP address to use when accessing the Local LAN ports of the U120.
Option b. WiFi LAN Connection
Instead of using a physical connection for devices connecting to the LAN the U120 can also be configured to use WiFi. See
WiFi on Local LAN later in the guide for details.
The default configuration for computers attaching to any of the U120 Local LAN ports is DHCP. If you are not sure if you
are using DHCP for your LAN IP addressing, please contact your Information Services (IS) Department for assistance before
proceeding.
If your computer is configured to use DHCP, but the U120 is not providing your computer with an IP address, please contact
your IS Department. In this case you will not be able to access the web Interface as described below.
Note: After the U120 has retrieved its configuration, the local LAN addresses are likely to change from the default values.
If the IP addressing does change, it may be necessary to reboot or reconfigure your devices attached to the U120 in order
to obtain/assign a valid IP address to use when accessing the Local LAN ports of the U120.

8
Configuring the U120 Internet Connectivity
In most cases, no user-level configuration is required to set up the WAN connection as an IP address is retrieved
automatically through DHCP and the device configuration is retrieved from the network. In some cases, it is necessary to
perform some initial configuration through the web Interface –for example, if the primary Internet connection needs to be
manually configured prior to use. To do this it will be necessary to access the U120 web interface.
Access the U120 Web Interface
The U120 web interface can be accessed from a computer attached to a LAN port. The web interface can be used to access
various administration functions and can allow the VPN connection to be controlled.
1. Open your web browser.
2. In the Address or Location box enter http://attvpngateway.att.com and press the Enter key.
3. This will take you to one of several possible initial pages, depending on your configuration and connectivity
options. A menu will appear on the left side of each page for access to sections such as “Home”, “Network
Settings”, and “Help”
If the U120 has already retrieved its configuration, it may have been configured for Administrator access. See Administrator
Access later in the guide for more information on gaining administrator access to the web interface.

9
Primary IPv4 WAN Interface Setup
To configure the primary interface for something other than DHCP (or to change DHCP settings), follow these steps:
1. Access the web interface as described on page 8.
2. Click the entry for Network Settings to display the Network Settings sub-menu and click the entry for WAN Setup
as shown in Figure 2: Network Settings Selection.
Figure 2: Network Settings Selection

10
Configuring DHCP
To configure DHCP, follow these steps after reaching Figure 3: DHCP Settings
1. Select “DHCP” from the choices that are displayed.
2. Check the checkboxes for the DHCP options required by your ISP in Figure 3: DHCP Settings. Most ISPs do
NOT require any of these checkboxes to be set. If needed, populate the VLAN fields as defined by your ISP. Most
ISPs do NOT require VLAN information to be specified. Therefore, unless you have special circumstances you
should be able to just skip to the next step.
3. Press Submit to display a confirmation dialog where you can review the new WAN setup.
4. Press Confirm to initiate a reboot to pick up the new configuration. After reboot, skip to the section titled
“Establishing VPN Connectivity”on page 21.
Figure 3: DHCP Settings

11
Configuring a Static IP Address
To configure a static IP address, follow these steps after reaching Figure 4: Static IP Settings:
1. Select “Static”from the choices that are displayed.
2. Enter the Static IP information requested on Figure 4: Static IP Settings. Fields that are marked with an asterisk
are required and must be populated. The Static IP information is provided by your ISP and the “Primary DNS”
would be your ISP’s DNS server.
3. If needed, populate the VLAN fields as defined by your ISP. Most ISPs do NOT require VLAN information to be
specified.
4. Press Submit to display a confirmation dialog where you can review the new WAN setup.
5. Press Confirm to initiate a reboot to pick up the new configuration. After reboot, skip to the section titled
“Establishing VPN Connectivity” on page 21.
Figure 4: Static IP Settings

12
Configuring IP Unnumbered
To configure IP Unnumbered, follow these steps after reaching Figure 5: IP Unnumbered Settings:
1. Select “IP Unnumbered”from the choices that are displayed.
2. Enter the IP Unnumbered information requested on Figure 5: IP Unnumbered Settings. Fields that are marked
with an asterisk are required and must be populated. The IP Unnumbered information is provided by your ISP and
the “Primary DNS” would be your ISP’s DNS server.
3. If needed, populate the VLAN fields as defined by your ISP. Most ISPs do NOT require VLAN information to be
specified.
4. Press Submit to display a confirmation dialog where you can review the new WAN setup.
5. Press Confirm to initiate a reboot to pick up the new configuration. After reboot, skip to the section titled
“Establishing VPN Connectivity” on page 21.
Figure 5: IP Unnumbered Settings

13
Configuring PPPoE
To configure PPPoE Account information, follow these steps after reaching Figure 6: PPPoE Settings:
1. Select “PPPoE”from the choices that are displayed.
2. Enter the information requested on Figure 6: PPPoE Settings.Fields that are marked with an asterisk are
required and must be populated. The PPPoE information is provided by your ISP.
3. DNS addresses are not required, but if you populate them then they would be your ISP’s DNS servers.
4. If needed, populate the VLAN fields as defined by your ISP. Most ISPs do NOT require VLAN information to be
specified.
5. Press Submit to display a confirmation dialog where you can review the new WAN setup.
6. Press Confirm to initiate a reboot to pick up the new configuration. After reboot, skip to the section titled
“Establishing VPN Connectivity” on page 21.
Figure 6: PPPoE Settings

14
Configuring a Cellular Connection
Only U120 units distributed in the United States have an internal modem. If your U120 does not have an internal modem
then you can skip this part.
To configure an Always-On Cellular connection, follow these steps after reaching Figure 7: Cell Settings:
1. Ensure that a SIM has been inserted into the U120 SIM1 slot. The power should be turned off when the SIM is
inserted. If you inserted the SIM when the power was on then turn the U120 off and back on again.
2. Make sure that the two antennas are attached to the back on the U120.
3. Select “Cell” from the choices that are displayed.
4. Select your “Connection Method”from one of the choices shown in Figure 8: Cellular Dial as Primary Settings
- Modem Properties. For a cellular connection that will be always-on you would choose “Constant Connection”.
Selecting “User Managed Persistent” would configure a cellular connection that is persistent but could be connected
and disconnected at will.
5. The Access Point Name (APN) is an optional field.
6. Optionally enter the user ID and password provided by your cellular service provider. Some networks/APNs don't
use the user ID and some cellular service providers require that the user ID is NOT sent in the authentication flow.
7. Press Submit to display a confirmation dialog where you can review the new WAN setup.
8. Press Confirm to initiate a reboot to pick up the new configuration. After reboot, skip to the section titled
“Establishing VPN Connectivity” on page 21.

15
Figure 7: Cell Settings
Figure 8: Cellular Dial as Primary Settings - Modem Properties

16
Cellular service verification
After completing the setup of either mode of the cellular connection, it is important to determine that there is adequate signal
strength before deciding on a final installed position. Cellular coverage can vary, even over a short distance, and a bad
placement of the AT&T U120 can result in substandard or even non-existent cellular service.
The signal strength will be displayed on the front panel, right side. If the LED labeled “LTE” is displaying blue then the SIM
is active and the signal strength LEDs will display the signal strength.
A paper clip or a similar shaped object will be required to properly depress the “SIM SELECT” button in order to change the
SIM slot used by the internal modem. The SIM should be inserted when the power is off.
Figure 9: Cellular Signal Strength Display
The unit should be installed in a location that gives optimal signal strength.

17
WiFi WAN Interface
The U120 can be configured to use WiFi as the primary WAN interface.
Configuring WiFi DHCP
To configure WiFi DHCP, follow these steps after reaching Figure 10: WiFi DHCP Setup
1. Select “WiFi DHCP” from the choices that are displayed.
2. Check the checkboxes for the DHCP options required by your ISP in Figure 10: WiFi DHCP
Setup. Most ISPs do NOT require any of these checkboxes to be set.
3. The “Frequency Preference” is optional and lets you specify 2.4 GHz or 5 GHz. Note that if you
select a specific frequency and it is not available then the connection will not be established.
4. The asterisk indicates that SSID is required to be populated. Instead of manually configuring it
you can select a choice from the “Scanned SSIDs”drop-down menu, which populates
dynamically. When a value is selected in this drop-down menu it populates the SSID input
field. Some WiFi networks expect the SSID field to be populated when you connect to them.
5. The optional Shared Secret field has a slashed eye icon that can be used to toggle visibility.
6. The “Authentication ID” field is only for WPA or WPA2 enterprise connections. When
connecting to a WPA or WPA2 WiFi connection this field will be provided by your ISP.
7. Press Submit to display a confirmation dialog where you can review the new WAN setup.
8. Press Confirm to initiate a reboot to pick up the new configuration. After reboot, skip to the
section titled “Establishing VPN Connectivity” on page 21.
Figure 10: WiFi DHCP Setup

18
Configuring WiFi Static
To configure a WiFi Static IP address connection, follow these steps after reaching Figure 11: WiFi
Static Configuration:
1. Select “WiFi Static”from the choices that are displayed.
2. Enter the Static IP information requested on Figure 11: WiFi Static Configuration. Fields that
are marked with an asterisk are required and must be populated. The Static IP information is
provided by your ISP and the “Primary DNS” would be your ISP’s DNS server.
3. The “Frequency Preference” is optional and lets you specify 2.4 GHz or 5 GHz. Note that if you
select a specific frequency and it is not available then the connection will not be established.
4. The SSID is required to be populated. Instead of manually configured it you can select a
choice from the “Scanned SSIDs” drop-down menu, which populates dynamically. When a
value is selected in this drop-down menu it populates the SSID input field automatically. Some
WiFi networks expect the SSID field to be populated when you connect to them.
5. The asterisk indicates that SSID is required to be populated. Instead of manually configuring it
you can select a choice from the “Scanned SSIDs” drop-down menu, which populates
dynamically. When a value is selected in this drop-down menu it populates the SSID input
field.
6. The optional Shared Secret field has a slashed eye icon that can be used to toggle visibility.
7. The “Authentication ID” field is only for WPA or WPA2 enterprise connections. When
connecting to a WPA or WPA2 WiFi connection this field will be provided by your ISP.
8. Press Submit to display a confirmation dialog where you can review the new WAN setup.
9. Press Confirm to initiate a reboot to pick up the new configuration. After reboot, skip to the
section titled “Establishing VPN Connectivity” on page 21.

19
Figure 11: WiFi Static Configuration

20
Administrator Access
One or more users may be designated as administrators by your IS Department. If your U120 was set up for administrator
access, Figure 12: Administration Panelis displayed and you must select your access level. You must be a designated
administrator to configure or control the U120. Select Administrator, enter the password provided by your IS Department,
and click OK.
Selecting General User and then clicking OK restricts the current session to be view only. Certain functionality, such as the
ability to terminate the VPN connection, is disabled.
If an Administrator password is not required Figure 12: Administration Panel is not displayed. The U120 must be able to
retrieve configuration from the network in order to implement Administrator access.
Figure 12: Administration Panel