Nuisance Calls and Spam-over-Internet-Telephony
Tip: In your sipgate account Settings you can blocklist numbers you've received unwanted caller's numbers: Blocking Unwanted Calls (Blocklisting) .
Many telephone handsets and VoIP phones offer options to block anonymous or specific callers. If you are receiving calls from IP addresses or from incomplete or invalid numbers that are not listed in your sipgate account's event list (commonly known as SPIT calls, or Spam over Internet Telephony), you can find further information in this article. SPIT involves unsolicited and often automated calls made over the internet, similar to email spam but delivered via voice calls.
Tip: Inform unwanted callers that you do not wish to be contacted again, also do not engage unwanted callers in further conversation and try to end the call as quickly as possible. Engaging the caller in conversation may only lead to even more unwanted calls.
Telephone Preference Service (TPS)
As an option to reject unwanted calls, you can register for free with the Telephone Preference Service (TPS). The Telephone Preference Service (TPS) is a freely available service. It is the official UK central opt out register on which you can record your preference not to receive unsolicited sales or marketing calls. It is a legal requirement that all UK organisations (including charities, voluntary organisations and political parties) do not make such calls to numbers registered on the TPS unless they have your consent to do so. As TPS registration only prevents marketing calls, organisations will still be able to call you for the purposes of genuine market research.
Tip: You can register with TPS using this link.
Blocking Spam and Anonymous Calls Directly on Your Device
Some devices already have the setting to block unwanted calls built into their functionality; these devices are summarized in the table with brief comments.
| Snom IP Deskphones |
With Snom Phones callers and Contact's can be easily added to a deny list. To block anonymous calls add the following contact in the Directory menu of your phone: Name: Anonymous |
| Gigaset DECT Handsets | Many Gigaset DECT Handsets support "Anonymous Call Silencing". Some Gigaset handsets also come with blocklists to selectively screen or block specific numbers. |
| Yealink Deskphones | Yealink IP Phones offer anonymous call rejection and blocklisting options. |
| Grandstream | Grandstream adaptors and deskphones support Anonymous Call Rejection. |
| Cisco/Linksys SPA | Anonymous calls can be blocked in the device settings. Using 'Selective Call Forwarding' specific numbers can be blocked. |
| Panasonic | Anonymous calls can be blocked in the device settings. Using 'Selective Call Forwarding' specific numbers can be blocked. Recent Panasonic DECT handsets offer Nuisance Call Block options to block specific callers and anonymous calls, while older handsets often offer some Call Barring options. Further information can be found in Panasonic FAQ: Blocking Calls. |
| BT Home Phones | BT Home Phones offer call blocking as standard with a wide range of options available including Do Not Disturb. |
Receiving Direct IP (SPIT) Calls from Numbers Like 100, 1001 and IP Addresses?
Many phones support Direct IP calls allowing one VoIP phone to call another VoIP phone by dialling the destination phone's IP address, without using a service like sipgate. Unwanted or nuisance Direct IP Calls are called SPIT calls (Spam over Internet Telephony).These calls aren't being made to your sipgate phone number or routing over our network. You will need to review your local network and VoIP phone configuration to block these types of calls.
Important: As this will be a local network and phone security issue, the best support and assistance will be provided by your local IT administrator with support from your VoIP device and/or router manufacturer's support teams.
Using a Local or Listen SIP Port value (e.g. 44160) other than the default port value 5060 should put an end to these types of calls. While this may stop these calls, this step alone is not a solution. Most recent VoIP phones will have an option to disable Direct IP Calls. Most quality VoIP phones and devices will also have other settings that can be used to block these SPIT calls:
| Device | Comments |
| Grandstream Deskphones |
The available options will vary depending on the model of your phone.
|
| Snom Deskphones (Firmware Version v8) |
Under Advanced → QoS/Security, set the option "Filter packets from Registrar" to Yes. Your router should also have a wide range of security options. You should contact your router manufacturer's support for advice and recommendations. At the very minimum as an initial step, please change your sipgate login and SIP Password, change the administrator passwords and update the firmware used by your VoIP phones, routers, and other networked devices as well as scanning your computers, smartphones, etc for viruses and malware. |
Tip: If your router firewall supports the option, you could limit VoIP traffic to our IP ranges:Security Settings: sipgate IP & Port Ranges.
Ultimately, your local network's configuration and its security is your responsibility and outside sipgate's scope of support. If you're receiving SPIT Calls, the best source of help will be provided by your VoIP phone and/or router manufacturer's support staff.