An area of concern that comes up when discussing movement from traditional digital telephone lines, ISDN2 and ISDN30, to a VoIP solution is “how secure is SiP?”.

When choosing your SiP provider, it’s important to do a little due diligence on the product you’re looking at.

Firstly, find out who supplies the service. There is a lot of white label products out there but its key to know who is the true provider.

Your SIP provider should provide a monitored service with fraud management, QoS (Quality of Service) and reliability.

To make sure you are getting a secure SiP product there are some simple things to check.

Does the product have a fraud management service?

I keep talking to business owners who’ve had their telephone system hacked or hi-jacked, known as Phreaking or Toll Fraud, and have raked up huge bills that these criminal gangs benefit from for their own financial gain. This tends to be because the call traffic has no monitoring capability either at the customer premises or more importantly at the network level.

So make sure your SiP provider offers monitoring, alerting and online access that will allow you to set alarms on your traffic alerting you if anything out of the norm happens. You also want the service provider to have the ability to bar the service if they see something. Remember most of these attacks happen over weekends when offices are closed and nobody is working to maintain regular checks on this.

Access Control

If your service has or is deployed correctly the architecture will include application layer access control on top of the standard network level firewall and some sort of authentication architecture. Session border control is an important feature that should be included in the architecture this allows control between the trusted enterprise network and untrusted carrier trunks.  NAT (Network Address Translation) is a key aspect of access control and will shields the enterprise’s infrastructure the end point and users from external parties.

Threat Mitigation

The security architecture must proactively monitor and guard against the threats with phreaking, toll fraud, identity theft and unsolicited call monitor.  All these should be monitored at Network level, 24/7, with the ability to bar the traffic if a breech s detected.

For more information on Phreaking and Phone Hacking, please read my blog using this link:

To find out more about your current SiP set up or the possibility of having SiP, please call me on 0330 333 2 333 or email me at