Block unwanted Direct IP calls (SPIT) on sipgate VoIP phones – protective measures and settings.
Many phones support direct IP calls. This means that a VoIP phone can call another directly via its IP address without using a service like sipgate. Unwanted or disruptive direct IP calls are called SPIT calls (spam over Internet telephony).
These calls are not routed through your sipgate number and do not run over our network. To block them, you need to adjust your network settings and the settings of your VoIP phone.
Important: Since this is a network security issue, you will get the best support from your local IT administrator or the support team of your VoIP device or router manufacturer.
One way to stop these calls is to use an alternative SIP port (e.g. 44160) instead of the standard port 5060. However, this alone is often not enough.
Many modern VoIP phones offer the option to disable direct IP calls. High-quality devices also have additional settings to block SPIT calls:
The exact options depend on the model.
Most Grandstream models have an option Disable Direct IP Calls (found under Settings ➔ Advanced Settings).
In the profile or account settings, you can Check SIP User ID for incoming INVITE on YES set. Alternatively, under Account X ➔ SIP Settings ➔ Security Settings there is the option Accept SIP requests from proxy onlyThis should also be set to YES set.
Go to Advanced ➔ QoS/Security and set the option Filter packets from registrar on Yes.
Your router also offers various security options. Contact your router manufacturer’s support team for advice.
As a first step, you should change your sipgate login and SIP password, update the administrator passwords, and bring the firmware of your VoIP phones, routers, and other network devices up to date. Also check your computers, smartphones, etc. for viruses and malware.
If your router firewall supports it, you could restrict VoIP traffic to sipgate’s IP ranges:
If you continue to receive SPIT calls, it is best to contact the support team of your VoIP phone or router manufacturer.
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