Configuring the ATM VC

Topics on this page: Viewing Your ATM VC | 
Modifying ATM VCs  | Adding ATM VCs  

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The devices WAN-side interfaces are used to communication via the ADSL port. A WAN interface comprises two layers: a lower-level ATM VC interface and a higher-level protocol interface: 

  • The ATM VC interface enables the device to communicate using the Asynchronous Transfer Mode protocol. The ATM protocol provides a common format for transmitting data over a variety of hardware systems that make up the backbone of the Internet. The virtual circuit (VC) properties of the ATM VC interface identify a unique path that your ADSL/Ethernet router uses to communicate via the ATM-based network with the telephone company central office equipment.
  • The higher-level protocol interface(s) operate "on top" of the ATM VC interface. The higher-level interface handles the protocols needed to log onto and exchange data with the ISP's access server. ISPs can use several different protocols, including the Point-to-Point Protocol (PPP), Ethernet-over-ATM (EoA) protocol, or the Internet Protocol-over-ATM (IPoA). Be sure to create the specific type of WAN interface your ISP requires. 

After you have defined the ATM VC properties as described in this topic, you can configure one of the higher level WAN interfaces to enable communication with your ISP.

Viewing the ATM VC Configuration

The ATM VC Configuration table displays the following fields (contact your ISP to determine these settings):

  • Interface: The name of the lower-level interface on which this VC operates. The low-level interface names are preconfigured in the software and identify the type of traffic that can be supported, such as data or voice. Internet data services typically use an AAL5-type interface.
  • Vpi, Vci, and Mux Type: These settings identify a unique ATM data path for communication between your ADSL/Ethernet router and your ISP.
  • Max Proto per AAL5: If you are using an AAL5-type of  interface, this setting indicates the number of higher level interfaces that the VC can support (the higher level interfaces can be PPP, EoA, or IPoA interfaces). Contact your ISP to determine which connection protocol(s) they require.
  • Actions: Displays icons you can click on to modify () and delete () the associated interface. You cannot delete an ATM interface if another protocol such as PPP, EoA, or IPoA has been defined to operate over the ATM interface. Delete the higher-level interface first, and then delete the ATM interface.

Modifying ATM VCs

Your device may contain placeholder values that you must change to establish an ATM connection. Contact your ISP to determine your ATM VC values. 

Follow these instructions to modify a preconfigured VC:

  1. From the ATM VC Configuration page, click in the Actions column for the interface you want to modify. The ATM VC Interface - Modify page displays.
  2. Enter the new VPI and VCI values, select the MUX type, or change the maximum number of protocols that the VC can carry, as directed by your ISP.
  3. Click Save. A page displays to confirm your change.
  4. Click Close to return to the ATM VC Configuration page and view the modified interface in the table.

NOTE: If want your changes to be permanent, be sure to Write Settings to Flash.

You can verify that the new settings work by attempting to access the Internet from a LAN/USB computer. Contact your ISP for troubleshooting assistance.

Adding ATM VCs

You may need to create a VC if none has been predefined on your system or if you use multiple services with your ISP. Each service may require its own VC. Follow these instructions to add a VC:

  1. From the ATM VC Configuration page, click Add to display the ATM VC - Add page.
  2. Select an interface name from the VC Interface drop-down list.
  3. Enter the VPI and VCI values assigned by your ISP, and select the MUX type from the drop-down list.
  4. In the Max Proto per AAL5 text box, enter the number of higher-layer protocols that you will use over this VC connection (e.g., PPPoE, PPPoA, EoA).
  5. Click Save and then click Close to return to the ATM VC Configuration page and view the new interface in the table.
  6. Verify that new settings work properly, and, if you want the changes to be permanent, be sure to Write Settings to Flash.

You may need to create a new WAN interface, or modify an existing interface, so that it uses the new VC. See the help for PPP, EoA, or IPoA interfaces, depending on the type you use to communicate with your ISP.