Knowledgebase

Browse articles on provisioning IP phones and troubleshooting PBX-related problems. Learn new ways to configure your phone system and maximize its functionality. Access Knowledgebase

User Guide

Read the official user guide and learn how to setup all of its built-in features. Read this guide for tutorials on call flow management (mobile app included) and softphone creation. Access User Guide

Questions?

Frequently asked questions (FAQ) are listed questions and answers, that are commonly asked. These FAQs will help answer many questions you have in mind concerning our services. Access FAQs

Random Ghost or Anonymous SIP Calls

Ghost calls occur when one or more SIP devices ring at random times from call displays such as 100, 1000, Anonymous or some other unrecognized ID. If answered, there is silence from the other end.

The problem arises when SIP calls go out to too many IP addresses on the standard SIP port, 5060. By default, many phones connect to service providers and listen for incoming calls on port 5060. This "listen port" or "local port" can be changed to non-standard values to rectify this problem. For instance, we recommend port numbers between 9000 and 40,000. Basic firewalls sometimes default to this same port, while higher end network devices scramble ports, ensuring port 5060 does not remain open.

There are many solutions for this problem. Typically, any one of them will correct the issue.

  • Disable anonymous SIP calls, so that your phone only receives calls from the server to which it is connected (See "Disable anonymous SIP calls" further down the page).
  • Use a high-end router or firewall device to "rewrite source ports" on outgoing packets. Doing so also adds an extra layer of security to your network. A good example of a free open-source router/firewall is pfSense
  • Change the local SIP port on all of your phones. Make sure you do this on all phones—not just the one or two affected. By default, your first phone will "grab" port 5060, and the remaining phones will default to ports like 5061, 5062, 5063 and so on. If you only fix the problematic device, another phone will eventually takeover port 5060. To prevent this from happening, look for a setting called "local SIP port" or "listen port". Change it to anything else, such as numbers in the 9000 range.

Disabling Anonymous SIP Calls

Please see sample instructions on how to disable anonymous SIP calls below. Other phones should have very similar settings.

Grandstream DP 715

  • Login to your phone via the web using its IP address
  • Click on the menu bar "PROFILE 1"
  • Locate "Allow Incoming SIP messages from SIP Proxy Only" in the "Advance Settings" sub-menu
  • Click on "Yes"

Grandstream GXP 2130

  • Login to your phone via the web using its IP address
  • Click on “Accounts” tab
  • Choose “Account 1”
  • Click on the left menu option “SIP Settings”
  • Choose “Security Settings“
  • Locate “Accept Incoming SIP from Proxy Only“
  • Click “Yes“

Yealink

  • Login to your phone via the web using its IP address
  • Click on the menu bar “Features’’
  • Find "Allow IP Call" in the “General Information“ sub-menu
  • Choose “Disabled”