How to Set Up the Linksys PAP2T Telephone Adapter

This guide explains how to set up the Linksys PAP2T and Cisco SPA112 Analogue Telephone Adapter to connect to the SureVoIP Single User and Hosted VoIP service.

For more information on the Cisco range of IP phones, please visit the Cisco phones product website.

Please note the Cisco SPA112 FXS Port Adapter replaces the Linksys PAP2T.

This guide has been superseded by How to Set Up the Cisco SPA100 Series Telephone Adapter.

  1. Obtain the ATA IP address.
    1. Dial * * * *
    2. Enter 110#
    3. The IP address will be played back.
  2. Type the IP address into your web browser.
  3. Once the page has loaded, press Admin Login then press advanced
  4. Go to the SIP tab
  5. Scroll down to RTP Parameters and sets RTP Packet Size to 0.020 :!: This is often overlooked.
  6. Scroll down to NAT Support Parameters and set Handle VIA rport and Insert VIA rport to no
  7. Go to the Line 1 tab (or Line 2 if Line 1 is already being used)
    • Set Line Enable to yes
    • Set NAT Mapping and NAT Keep Alive to yes
    • Set Proxy to the SIP Proxy/Registrar Server provided in your welcome email
    • Set Register to yes
    • Under Subscriber Information put your name into Display Name
    • Put your auth ID (extension number) into the User ID and Auth ID fields. This is provided in your welcome email.
    • Put your provided SIP password (also referred to as SIP Secret) into the Password field
    • Set Use Auth ID to yes
    • Set Preferred Codec to G711a or set to G722 if on SureVoIP Multi-User Hosted.
    • Put

      into the dialplan.

  8. Click Submit All Changes
  9. Once the phone has rebooted and is back online, go to the Info tab and scroll down to Line 1 Status and check the Registration State shows Registered

Additional Settings

These are optional settings, but are highly recommended to get the best experience out of your phone.

Set Time Servers

In System tab, under Optional Network Configuration

  • Set Primary NTP Server to
  • Set Secondary NTP Server to

Use the above as an example as your system administrator may be able to provide you with your company's internal NTP servers.

In Regional tab, under Miscellaneous

  • Set Time Zone to GMT
  • Set Daylight Savings Rule to start=3/-1/7/2:0:0;end=10/-1/7/2:0:0;save=1:0:0
  • Set Ignore DHCP Time Offset to no
  • Set Locale to en-GB

If registration is failing, check over the settings entered above.

Ensure SIP ALG is disabled on your router. See this page for further information.

If the Status page shows timeout, check over your firewall settings.

If you are having issues dialling out, go to Regional tab and at the Vertical Service Activation Codes section remove all the feature codes.

ie Call Return Code, Blind Transfer Code and so on should be blank.

If you find dialling international numbers causes beeping before you finish dialling, then under Regional tab and under Control Timer Values (sec) section increase Interdigit Long Timer and Interdigit Short Timer.

If you are experiencing issues with voice (hearing the caller or the caller hearing you and so on), then ensure you have followed Step 5 above.

If you are still having trouble registering, contact SureVoIP Technical Support.