Phone number spoofing

[#1]

I use Vonage residential VOIP as a replacement for the old copper landline.

Over the last few months I have been receiving a number of calls with apparently spoofed caller id numbers.

Initially they spoofed local dialing codes. More recently they have been using a range of 020 London codes.

The last couple of days , the dialing code has been 01274 (Bradford).

If I leave the call unanswered, they never leave a message on the answer machine.

If I pick up the receiver and say nothing, the call hangs up.

As far as I can see, apart from changing my phone number, there is no way to stop these nuisance calls.

I am unable to block the numbers because they keep changing and Vonage does not allow wild cards when configuring the blocked numbers list.

It seems to me that telecomm companies could stop this if they wanted but choose not to. I guess it's because they make money from the calls. I am considering giving up VOIP altogether and just use my mobile.

Can anyone offer a solution?

[#2]

I remember looking into this years ago, but in reverse. The Company I worked for made muliple London to New York calls daily. It was found to be cheaper to lease an continental  line and divert calls through this line. The benefit was cost saving the unintended effect was that to the New York offices the calls seemed to be local.

Reversing the setup means that overseas entities could make questionable calls to the UK appearing to originate in the the UK.  

[#3]

This is the information given by the Ofcom website:-

What is being done?

Calls with spoofed numbers can and do come from all over the world and account for a significant and growing proportion of nuisance calls.

That's why Ofcom is working with the international regulators – as well as the telecoms industry – to find solutions to the problem.

Voice over IP (VoIP) technology – the type of technology used to make internet calls – is often used in spoofing. The Internet Engineering Task Force (IETF), which helps to develop internet standards, has created a group specifically to tackle this issue.

In other words thay have not actually done anything!

It sounds like something from 'Yes Minister' - set up a committee and hope the problem goes away.

[#4]

I thought IPSec was supposed to protect IP packets from being tampered with.

[#5]

IPSec has nothing to do with VOIP.

[#6]

@briank 

I don’t know if IP phones have the same features but if you use an analogue phone with an ATA you can use a phone with a built in call blocker. The BT TrueCall phones work extremely well at stopping this sort of thing.

[#7]

I know very little about VOIP but my understanding is that you can send VOIP traffic over a VPN using IPSec.

[#8]

You can send just about any traffic over a VPN. 

[#9]

Unfortunately call blocking is of little use if the caller uses different spoofed ids each time (which many do).

A system that includes a white list of allowed numbers rather than a black list of blocked numbers may work, but only if you never need to pick up incoming calls from unknown numbers such as when you need to contact a tradesperson.

[#10]

@briank 

I suspect that you are unaware of how the TrueCall system works. When a call comes in, permitted numbers get straight through. Unidentified numbers are answered by the phone in the background and asks for the caller to identify themselves and press the hash keys. If the caller identifies themself then the phone rings and you have the choice to accept the call, pass it to the answerphone or reject it. Automatic diallers do not respond and are cut off without the phone ringing.

[#11]

I was unaware of the TrueCall system. It sounds like it should be effective.

One reservation is that my existing triple handset DECT phones were from BT (Stratus 1500) and they are rubbish!

They often fail to charge (despite being fitted with new decent quality Elenoop 750mAh NiMh batteries and the 'charging' LED being illuminated). When the battery voltage drops, the handset outputs a continual low battery alarm warning beep. This often happens in the middle of the night. What idiot at BT came up with that idea?

When I carried out an investigation I found that the 'charging' LED in the base unit doesn't actually indicate that current is flowing into the battery. It simply indicates that a current of over 2mA is flowing from the base unit into the handset i.e. the handset is 'on hook'. The handset samples the battery voltage and is supposed to switch the charging current on (around 30mA) when it drops below a threshold. Unfortunately this doesn't always work. I have three of these handsets + base units and they all suffer from the same problem. To me that suggests a design fault.

[#12]

@briank- BT Stratus 1500, don't mention that garbage in my presence! 😡

I've finally got rid of the 5, yes FIVE! handsets I had. They ALL had battery charging problems despite regular replacement with quality NiMh batteries. Fortunately I didn't buy them all, most I inherited or acquired via Freecycle attempting to find "better" ones.

Like you I concluded they had a design "feature"........  😫

Having moved to VOIP I now have Gigaset devices and they're all fine.

Re TrueCall, I have friends who use it and it's very effective.

[#13]

There was a time when BT was regarded as being synonymous with quality. Then managers and bean counters decide that outsourcing to China would be a cheaper option and it all went downhill.

I used to work for Marconi Instruments. The emphasis was on quality and designing products that were well engineered, built to last and tested under extreme environmental conditions.

No one seems to bother anymore. Build it cheap, sell it cheap, throw it away when it stops working. Just make money.

[#14]

It all started with built in obsolescence many years ago. Equipment built to fail after a certain period meant guaranteed future sales and the rocky road to throw away items with ever increasing prices. Greed.

[#15]

My TV is 14+ years old, my (now) back-up laptop as old and other odds and ends of electronic stuff possibly older - and still working. I have  replaced my fridge with a fridge-freezer, and microwave, in the last four or so years, but not because they failed, just that I needed to change them having re-configured my kitchen.