Digital Voice Security

[Theostream10]

Hi,

I have just been discussing my contract renewal, along with the possibility of upgrading to Fibre to the Property + Digital Voice. The young lady I spoke to was very helpful, but was unable to give a statement on the security of Digital Voice (she did try, but drew a blank with all of her colleagues). Does anyone know what the company statement is on this? Zen, for example, declare that their Digital Voice is encrypted, along with other (undeclared) security measures, they also see themselves as a cut above VoIP alternatives. They believe that their Digital Voice is more secure than a traditional landline. I would like to think that, as this is a replacement for the national landline infrastructure, all mechanisations of Digital Voice would be to the same standard, but I haven't come across any articles that indicate this is the case. As I currently use my landline phone for limited credit card, and banking, management, I would like to be sure that the system I am using is reasonably immune to the possibility of (for example) keystroke monitoring. Thanks for any help you can give.

[Michelle-TalkTalk]

Hi Theo,

Apologies for the delay. Can I just confirm, which question is still outstanding please?

Michelle

[Theostream10]

Hi,

Thanks for the response. I will follow this up with the customer team, if they don't post something here in the next few days (if I don't hear anything here, do you know of another way to contact the appropriate part of the organisation?). I did have detailed discussions on the topic of Digital Voice, when negotiating my contract renewal with the Loyalty Team - they tried very hard to find out information on this subject, but failed - they did, however, acknowledge that this is likely to become a topic of interest to customers as the landline switch off date approaches (Zen surveyed their customers, and 25% wanted to maintain an equivalent to landline, so it's not a niche requirement). It surprises me that Digital Voice does not appear to be implemented in a standard way by all Broadband Providers - it's replacing a part of National Infrastructure, so it really should be.

Given your experience, over the past year, it would be nice if they had something like the EE system, where you can make immediate changes to your phone options, via keycodes and a PIN, directly on your handset (even on a Noddy landline phone like mine!).

Thanks Again.

[Gliwmaeden2]

You should be able to see these as described here, @Theostream10:

https://community.talktalk.co.uk/t5/Articles/Add-or-remove-a-landline-bar-online/ta-p/2204904

Staff will clarify whether these apply as much to VOIP settings as to copper.

They won't be back on here before Monday. 

My Account has not been functioning well over the past year regarding the addition or deletion of boosts or display of what is available, so it is often necessary to request that choices are applied by forum staff  / phone or Chat support etc.

[Theostream10]

Hi Michelle,

Sorry for the delayed response, I have been away. I have a follow-up question.

Is the domestic DigitalVoice system susceptible to Phone Phreaking/Toll Fraud - where the phone line is effectively hacked and used for high cost calls? I am aware that EE/BT Digital Home Phone provide a comprehensive set of outgoing call barring options to minimise the impact of such an event - these options include all international calls, all operator calls, all calls to premium rate phone numbers etc. On the TalkTalk DigitalVoice page, I can only find reference to incoming call barring. Does TalkTalk allow outgoing call barring? If so, can it be managed directly through a standard landline handset (as is the case with EE, using a code string to enable, and a code string plus PIN to disable). If outgoing call barring is available, could you let me know the options available, and how they are managed (via app, handset etc).

Best Regards

[Michelle-TalkTalk]

Hi Theostream10,

Digital Voice is in many ways more secure than traditional landlines as calls cannot be physically intercepted as TalkTalk operates encryption of the call traffic over our part of the call route.  Once a call exits our network to go to another operator (i.e. if a TalkTalk Digital Voice customer is calling a business) then it may no longer be encrypted. This is to preserve call quality and is likely the case with other providers, though we cannot comment on their products and services.

Thanks

Michelle

[Theostream10]

Thanks for all the interest, and quick responses.

Gondola, I think you have allayed my fears. My broadband package will use a Hub 2 router - which I will directly connect my old landline base unit to (I will not be using the DigitalVoice App). With this very straightforward setup, the only thing even remotely 'at risk' would be the router itself - the security of which I have no control over.

I'll leave the question open a bit longer, to see if it prompts any comments from the 'up to date experts' you refer to.

Thanks

[Gondola]

Hi @Theostream10 

TalkTalk Digital Voice uses Metasphere from Metaswitch.

Metasphere uses Session Initiation Protocol (SIP) to set up and manage voice calls over the internet. SIP Secure (SIPS) encryption employs Transport Layer Security (TLS) and Secure Real-time Transport Protocol (SRTP). TLS 1.3 encrypts the SIP signalling, which is the information that sets up and terminates the calls, preventing hackers from manipulating or spoofing the SIP messages, stealing credentials or downloading malware. Secure RTP uses Advanced Encryption Standard (AES) as its default encryption cipher to secure voice data during calls, protecting against eavesdropping, recording conversations, and data theft. Session Border Controllers (SBC's) deployed at network interconnection points maintain security for calls transiting between networks.

The answer to your question is therefore easy. TalkTalk Digital Voice is as secure as anything connected via the Internet. TalkTalk keeps your router security up to date. You are still advised to keep your own security up to date on all your devices to prevent malware from entering your system by another route. e.g. email for example. Metaswitch being owned by Microsoft means that there are huge resources to further guard against security threats that evolve.

I do not expect TalkTalk to discuss security aspects but I'm certainly interested in what the up to date experts may say. 

[KeithFrench]

Hi @ferguson 

Analogue voice is not encrypted in any way to start with. Digital Voice will use RTP packets to transport the conversation and going back to when I was at work, there was no mechanism to encrypt it's payload (the conversation). It was possible to extract the voice stream & play it back. There was a small demand for encryption but that must have been done in software, before being passed to the network stack.

I must stress that my knowledge is IP networking and not voice application security.

[ferguson]

Ah OK, glad I asked! Do you think, just interested in an opinion here, that VoIP could be intrinsically more risky than current landline, or mobile phone banking transactions which require keypad input? 

[KeithFrench]

In this case @ferguson, I would need some sort of fibre broadband analyser I could put on the ONT that could give me a packet trace in Wireshark format. Another alternative is it could possibly be done on my PC running Wireshark via a managed switch costing probably around £1000 or more. Then I would stand a chance. Of course, I am not going to make that sort of spend when they don't pay us.

[ferguson]

You've lost me there bud, not for the first time! Analysing what exactly?

[KeithFrench]

Fraid so @ferguson, all I can tell is that it works. Now back in the day, when I had numerous expensive commercial analysers to use, it might have been different.....

[ferguson]

"Even" you @KeithFrench?  😂

[KeithFrench]

That is a very complex question that even I can't answer as I have no way of testing it. One for the TalkTalk devices team I think. I'll pass this over to TalkTalk for their comments.