Cisco SPA112

This guide shows you how to configure a Cisco SPA112 for use with your OntheNet VoIP service.

When to use this guide

All equipment that is supplied by OntheNet is pre-configured therefore in most cases you will only need to follow the first part of this guide to the connect the ATA to your modem.

The other sections of this guide may be useful when:

  • You have performed a factory reset and need to completely reconfigure the device.
  • You have purchased the device from someone else and need to configure it for your OntheNet service.

1. Connect an Ethernet cable between the Internet port on the SPA112 and an Ethernet port on the modem.

2. Connect the SPA112 to mains power using the supplied power adapter – the Power and Internet LED on the ATA should then light up.

3. Connect an analogue telephone to the Phone 1 port on the SPA112 using a phone cable.


Please note: All equipment that is supplied by OntheNet is pre-configured which means you only need to follow the process above to connect the ATA to your modem. If you have reset the device or purchased it elsewhere please follow these steps to configure the ATA with your OntheNet user details.

1. The Cisco SPA112 will need to be connected to a modem for it to be configured (as above). How to connect and configure your modem for Internet access.

2. Log in to the SPA112 as follows:

  • The IP address for web access will be determined by the type of modem the SPA112 is connected to. For Netcomm the IP should be To find out the the IP dial **** on the telephone (there will be no dial tone) and then 110# for the IVR to read back the IP address.
  • Enter the IP address in a web browser to bring up the login page.
  • Log in with the following details:
    Username: admin
    Password: admin


3. Click on the Voice tab and select Line 1 on left and configure the settings as follows

4. NAT Settings:

  • NAT Mapping Enable: Yes
  • NAT Keep Alive Enable: Yes


5. SIP Settings:

  • SIP Transport: UDP


6. Proxy and Registration:

  • Proxy:
  • Outbound Proxy:
  • Register Expires: 900
  • Use DNS SRV: Yes
  • DNS SRV Auto Prefix: Yes
  • Proxy Redundancy Method: Based on SRV Port


7. Subscriber Information:

  • User ID: Enter the Line ID (aka User ID) from your OntheNet VoIP Service Details
  • Password: Enter the password from your OntheNet VoIP Service Details
  • Use Auth ID: no


8. Audio Configuration:

  • Preferred codec: G729


9. Dial Plan:

  • Change Dial Plan to the following. This will reduce the delay after dialing a number before the call goes through.

10. Click Submit to save changes.

11. If your VoIP Service has a second line repeat steps 6-13 for Line 2 before proceeding further.

12. Select SIP on left and configure settings as follows

13. NAT Support Parameters:

  • Handle VIA received: Yes
  • Handle VIA rport: Yes
  • Insert VIA received: Yes
  • Insert VIA rport: Yes
  • Substitute VIA Addr: Yes
  • Send Resp to SRC Port: Yes


14. Click Submit to save changes.

15. The Phone 1 LED on the SPA112 should light up once it has registered with OntheNet (as should the Phone 2 LED if Line 2 was configured).

16. Power cycle the SPA112 (disconnect/reconnect power).

17. Test the configuration by dialing the test number 8378 which will connect you to an echo test service if successful (nil charge). You will need to connect the telephone to the Phone 2 port on the ATA to test Line 2 (if applicable).