Configuring a Grandstream GXW-4104 / GXW-4108 and GCK System to Accept Incoming Calls from an Analog Line


The Grandstream GXW-4104 is a 4 port analog  VoIP gateway device which allows a GLOBALCOM system to interface to a PBX or the PSTN using analog tip and ring phone lines.

Note: The GXW-4108 is nearly identical, but has 8 ports. Configuration is identical to the GXW-4104, except that channels will range from 1-8, instead of 1-4.


Preparation and Requirements

  • The user has otherwise configured the GLOBALCOM controller with devices, zone groups, etc.
  • The user has configured the GXW-4104 to have a static IP on the same subnet as the GCK Controller.
  • This document applies to Release 3 of GCK Software or higher.
  • This document applies to GXW-4104 Firmware or higher (blue screens). The configuration menu screens are different from older firmware (yellow screens).
  • The analog phone line is configured with the following parameters:
    • Loop Start
    • Loop current should be 20 mA
    • On-hook voltage should be 48 VDC
    • Ringing voltage is usually ~ 96 VAC with various intervals in milliseconds between rings


Controller Configuration

In the GCK SMC configuration for the controller, do the following:

  1. Open the SMC. Log in as an administrator. Go to the Configuration → Telephone → SIP page.
  2. Set SIP Configuration Mode to External via Trunking.
  3. Configure the Telephone Prompting and Direct Action extensions as desired.
  4. On the Trunks → Inbound tab, in the Authentication section, set a Username, Password, and Extension of your choice. Remember these values.
  5. On the same tab, in the Basic section, ensure that the SIP Port is set to 5080, and that the SIP IP Address and IEDNET+ IP Address are both set to the IP Address of the GCK Controller.
  6. On the same tab, in the Registration section, select Disable Register.
  7. In the Outbound-->Proxy field, enter the IP Address of the GXW-4104. Note that Proxy is not the same thing as Outbound Proxy.
  8. Save the settings by clicking OK in the Trunks window and Save in the upper right corner.


Grandstream Device Configuration

In the Grandstream configuration web page, configure the various screens as indicated. Note: many settings require a trailing semicolon. If you omit this character, the device will not function properly.

  1. Accounts:
    1. Account 1:
      1. General Settings:
        1. Account Active: Yes
        2. SIP Server: IP Address of the GCK Controller.
        3. Click Save
      2. SIP Settings:
        1. SIP Registration: No
        2. Click Save
      3. Audio Settings
        1. Change all Vocoders to PCMU for installations in US, Canada, or Japan. Otherwise, set Vocoders to PCMA.
        2. Click Save
    2. User Account
      1. For each channel (1 - 4), enter the channel, SIP UserID, Authentication ID (same as UserID) and Authen Password. Password will not be shown. It will appear blank the next time you enter that screen. Set SIP Account to Account 1.
      2. Click Save.
  2. Settings:
    1. Channels Settings:
      1. DTMF Methods: ch1-4:2;
      2. Unconditional Call Forward to Following:
        1. UserID: ch1:111;ch2:222;ch3:333;ch4:444; where 111,222,333,and 444 are the Prompting or Direct Action extensions defined in Step 3 of the SMC Configuration above.
        2. Sip Server: ch1-4:p1;
        3. Sip Destination Port: 5080
        4. Click Save
  3. Networks:
    1. Configure a Static IP Address on the same subnet as the GCK Controller.
    2. Click Save.
  4. Maintenance
    1. Upgrade/Provisioning
      1. Automatic Upgrade: No
      2. Select Always Skip the Firmware Check
      3. Click Save
  5. FXO Lines:
    1. Call Progress Tones: configure as needed if using Tone Disconnect. These can be automatically set by doing a Line Analysis. This procedure is not covered in this document.
    2. Port Voice Setting: This is where incoming or outgoing gain is adjusted.
    3. FXO Termination
      1. Enable Current disconnect: ch1-4:Y;
      2. Current Threshold: ch1-4:100;
      3. Enable Tone Disconnect: ch1-4:N;
      4. Enable Polarity Reversal: ch1-4:N;
      5. Enable Call Supervision: ch1-4:N;
      6. AC Termination Impedance: can be automatically set by doing a Line Analysis. This procedure is not covered in this document.
      7. Port Caller ID Setting: This is dependent on the installation region. Typical US values listed below. Consult your PBX administrator for your specific installation.
        1. Number of Rings before Pickup:
          1. If Locked Extensions using Caller ID: ch1-4:2;
          2. Otherwise ch1-4:1;
        2. Caller ID Scheme: ch1-4:1;
        3. Caller ID Transport Type: ch1-4:1;
        4. Click Save
  6. Click the Reboot button in the upper right corner.