Telecoms cloud drives voice call value

Voice over IP, or Internet telephony, has been around since the 1990s, but the development of more powerful hardware codecs – and now software codecs – means that low-cost VoIP handsets are becoming standard issue in most offices. However, many of these handsets and their back-office systems have been left trailing in the last decade by developments in cloud computing, with telecoms following data storage and computing resources toward cloud environment adoption.

It's now possible, for example, to host regular geographic UK numbers (01xxx and 02xxx) in the cloud, and then deliver inbound calls to the device of your choice – this could be a regular landline, a mobile phone using 'conventional' GSM/3G cellular, or a mobile using VoIP technology delivered across 3G or Wi-Fi channel. At a pinch, VoIP will function acceptably well across 2G (GSM) data channels, but using NAT (network address translation) bridge technology to smooth the network data flow.

VoIP technology also means that a voice call can both originate and be delivered across a wide range of devices, including a laptop or desktop PC, or one of the growing range of tablet computing devices, as most of these devices support Wi-Fi connectivity. Something that many people are unaware of is the fact that it's also possible to port UK office or home phone landline into the cloud, just as if the cloud telecoms provider were an 'alternative carrier' like Carphone Warehouse's TalkTalk operation.

Before doing so, the question begs itself: why would you port your landline into the cloud? The simple answer is: non-existent or minimal monthly line rental and discounted outbound phone calls, as well as the ability to deliver a call to one or more devices, either simultaneously or on a sequenced ringing basis. Here's how it works.

Let's say a caller dials my 0114-299-xxxx VoIP cloud phoneline, which is notionally in my home town of Sheffield. The 'line' is actually hosted on a cloud telecoms service provider in Germany called SIPgate, meaning there is no line rental and discounted calls are the order of the day. The call is initially offered to my physical landline #1 in the study for 10 seconds, and is then offered to my physical landline #2 in the house. After a further 10 seconds, the call is offered to my Voxsciences voice-to-text line on a London number (020-3111-xxxx), and the caller leaves a voice message. That message is then transcribed to text, and I get an SMS.

I can also configure my cloud phoneline to simultaneously ring my home, office and mobile numbers; if I answer one line, the others stop ringing. There's more. By using a suitable VoIP app on my Android smartphone or tablet computer, I can deliver the VoIP calls on 0114-299-xxxx direct to my mobile device as a VoIP call – thereby cutting out the cost of a regular cellular call. I can also access my VoIP line when I'm outside of the UK, making and receiving calls as if I were at home and with a'UK caller ID. And I can use multiple devices, including my laptop in a hotel room if required.

This immense flexibility in originating and delivering voice calls is the direct result of developments in cloud computing and VoIP technology arenas in recent years. The software codecs – the code that converts an analogue waveform into digital (and vice versa) – have become a lot more powerful, and the processors on smartphones, tablets, and laptop computers have also increased in their power capabilities.

Exploiting the power of SIP

Looking at my desk, I can see five devices: two regular cordless phones parented on to the home business line and the home residential line respectively (pretty normal so far); an all-in-one 24in desktop computer running the Skype instant messaging/telephony client software/service (again pretty normal), and an Android smartphone running Acrobits plus my iPhone running Skype.

The Acrobits client app, which is available on multiple smartphone platforms, runs an open source version of VoIP technology known as SIP (see boxout, p87). There are a wide range of SIP apps available for smartphones, including Fring (free) and Groundwire (a business version of Acrobits). Most SIP client apps for smartphones are independently produced and the better ones cost anything from $0.99 upwards. Some – like Fring – are produced to run on a commercial VoIP service, but also support third-party SIP providers. That is why the Fring app for various smartphone platforms is available free of charge, and it's a good app to start your SIP journey with.

Skype is not SIP-compliant as it uses similar technology; but it uses a proprietary mechanism that is designed to support much more than a simple voice call, such as point-to-point and point-to-many video calls, electronic whiteboarding and many other communications methodologies.

What Skype lacks in terms of SIP compliance is more than made up for by the fact that there are tens of millions of Skype users worldwide – as I type this, there are 29 million-plus other users connected to the network on a regular weekday afternoon. You can make free Skype-to-Skype calls, as well as pay extra for outbound voice calls, which, of course, could well end up on a VoIP destination.

To be sure, Skype is an imperfect system, with some users reporting stuttered calls as the IP transmission path is never perfect. Likewise with SIP calls – especially over cellular connections – but there are easy-to-use technologies like the aforementioned NAT bridging to assist in such cases. NAT is used to assist IP transmissions in a variety of situations. The NAT bridge option within Acrobits (and seen on many other smartphone apps including Groundwire) routes the IP transmission via a third-party gateway.

This can be useful when it comes to solving inter-ISP transmission issues, as well as 'jittery' paths caused by 3G or 2G (GSM) signal problems. The Acrobits/Groundwire service costs a modest $0.99 a month to subscribe to. 

Some ISPs have their own SIP services, and also aggressively bandwidth shape their IP traffic at peak times. This means they may favour their own SIP service traffic and consign third-party SIP traffic to general IP traffic. Using a NAT bridge may solve this problem, but results may vary.

Classing in the telecoms cloud

This leads neatly into the other old say-so of you get what you pay for' when it comes to IP communications. Some CSPs (communications service providers) will offer a bundled deal of phone line, calls and broadband for a fixed monthly payment, while others will add in satellite or cable TV services as part of the deal. Some CSPs will even offer IPTV (IP Television) services, while many offer broadband Internet for free or at discounted rates.

Many – not all – of these free/low-cost broadband deals are anathema to a SIP call. At time of writing, one of my home broadband providers, Plusnet, for example, aggressively bandwidth-shapes most IP traffic on its budget broadband package – but as I am only paying £25 a month for the phone line, all regular voice calls and 10GB of broadband data traffic, I do not complain.

Effectively I get the broadband free, and only use it when my primary ISP's service is down for any reason. Plusnet (part of BT) does not bandwidth-shape its own branded SIP service, classing it as premium (Titanium) traffic, which means that my SIPgate VoIP service can be stuttered at peak times and where the call traverses the Plusnet network; but since my SIPgate VoIP traffic routes over my primary – and largely unfettered – ISP service, this isn't normally a problem.

Ultra-high speed broadband

Over the next year or so it's probable that BT and a number of third-party providers will increasingly start rolling-out out/expanding an ultra-high-speed broadband service called FTTC (fibre-to-the-cabinet).

Unlike conventional copper-delivered broadband, which typically supports download speeds of up to 20 Mbps, FTTC can support 48-, 80-, or a 100 Mbps speeds, with the final leg of the broadband connection delivered across the copper link between the local roadside phone cabinet and your premises.

Pricing on these services costs from £25 a month – which can actually be considered as very good value when viewed alongside standard copper-delivered broadband – but the ISPs will have to aggressively bandwidth-shape their IP traffic line as never before. This is because most adopters of FTTC – also known as BT Infinity – will be bandwidth hogs, viewing TV and routing all manner of other data traffic across their connection.

Anecdotal evidence suggests that SIP traffic delivered across a FTTC connection is excellent at the moment, but this situation also applied to the early days of SIP over domestic broadband a decade ago, so it seems most likely that SIP over FTTC connections may be bandwidth shaped.

Bandwidth shaping and too-many-users-on-one-exchange/connection is actually one of the reasons why Skype and SIP-based voice calls do not always work well across public access Wi-Fi networks at stations, cafes and hotels. *

Further information

• bit.ly/eandt-communications