VoIP Phone Systems & Services – The Full Breakdown

There are many ways of delivery voice calls in modern times. None has had such an impact as VoIP phone systems. These are calls that are placed over the internet to any phone whether it is an IP phone or traditional analogue phone. The terms most well know with VoIP phone systems are IP phone systems, internet phone systems, and hosted phone systems. All of these share the same core principle which is a phone call placed from an internet line to an exchange though SIP relays (which we will cover in far more detail)

When we refer to a VoIP phone system, we talk about communications offerings such as talk, or voice, fax to email and even SMS. All of these services traverse over the general public network services rather than a standard analogue PBX (public branch exchange), or the PSTN system. The way these calls are handled and placed is very similar to that of the traditional analogue and digital phone network in that calls are signaled, channeled, then digitally created for analogue conversion though encoding methods. Rather than being sent over a circuit based network, the digital voice information is converted to what is known as data-packet (a compressed voice packet). These packets mean that some consideration is required in regards to bandwidth resource to ensure that call quality remains to a very high standard.

Perhaps the earliest version, at least from a well know perspective was Skype. Skype was enjoyed by mainly home users wanting to make free phone calls from one PC to another, mainly overseas. As this was a peer to peer service, it meant that the phone call never hit the public exchange. As a VoIP phone system, Skype has traditionally failed as a service as there is a large hangover due to poor voice quality. The lack of quality was down to the early nature of Skype, after all it was the first mainstream pioneer. But also that consumers didn’t understand what made the service tick, such as bandwidth (you can image a frustrated phone call whilst someone streams a movie eating up all the bandwidth). In recent years Skype has been bought by Microsoft which has pushed the service back to a business led offering. The issue here is that other businesses got it right the first time round. Saffwood Communications which is based in Warrington made massive investments early on to have a presence for it’s hostedVoIP phone systems in 6 UK data centre’s allow it to provide outstanding redundancy at the soft-switch level to business across the UK.

VoIP phone systems use a variety of means to ensure that the calls are placed with high speed and quality, even on slower speed connections. This is achieved by the use of protocols which can prep a call and end the call when required. Specialized codecs that were traditionally used for video conferencing services have now been brought to bear to support the business focus service to allow voice and media to be relayed seamlessly. To help with HD voice services, voice packets can be compressed to reduce the amount of bandwidth which is required to make a VoIP call from a phone system. There are many well know and highly used codecs such as the G range, including G.729 which is often used for softhpones. Softphones are becoming increasingly popular with the advent of smartphones. These are installed an an app onto the phone then use the codec to route the voice call though 3G or 4G where wireless is not available to the phone. Typically a VoIP voice call uses 85K or bandwidth, but with compression this can be compacted down to 35K. An item to be aware of with compression is that as the data packet is smaller, if a section of it is lost, the call quality is effected more than it would be on a none compressed call. To understand this, imagine the call was 100 parts, and each part was a word. Now imagine that the call is 10 parts, each containing 10 words, if you lose 1 part, you lose more words. In reality each “part” is actually a packet of data which has been digitally compress and converted, ready to be converted to an analogue end point.

As mentioned, VoIP phone systems now pair with smartphones, IP phones and PC’s allowing businesses to have the flexibility they need covering cost, ease of business, mobility and scalability. In 2013, UK Benchmarking found that business moved towards VoIP by a landslide of 67% vs traditional phone systems such as panasonic, ISDN and other analogue systems. This was due to the high levels of features that are available on an IP based system vs. that of others which are premised based rather than hosted. For businesses in Warrington, we offer a free trial of our service, and offer our services to businesses UK wide.

How to Pronounce Terms

The most common term for voice over internet protocol is VoIP. This is mainly used by both businesses and consumers. It is pronounced ver-oi-p. Other less common terms used are ver-oi-pee, although this is more typical in the state than in the UK. Voice over IP is another very commonly used term. Businesses often assume that a hosted system means the same thing, but what is really refers to is where the equipment is based. We’ll cover this is more detail in this article.

So What is a Protocol?

A protocol is a method to get a voice to convert from a traditional packet to a digital packet and back again. There are proprietary ones and open. VoIP system examples of this include

The most widely used one is H323 which is actually a mixture of other protocols (confused yet, don’t worry, you don’t really need to know all this for your VoIP system to work. All you need to do is pickup a ringing line and have a conversation – we’ll worry about the rest). But anyway: these are used for short and long distance traffic, as well as local (LAN, or local area network). However better protocols have been developed, or bundled together in recent years (hence why Skype had such a terrible time of it). These newer protocols with most notably SIP entering the business market place. More on SIP later but this allowed businesses with existing hardware to befit from new services including IP best telephony

So who is using this technology?

The domestic user

In the mid 20th century a large developmental process was started which brought VoIP services to all parts of the UK including Warrington. As broadband become less expensive, quicker (with the advent of ADSL2 and fibre) and more stable, home users were increasing able to use the service. Unlike businesses who often had dedicated lines for broadband, home user had a single line with broadband on it. This heralded the ATA, analogue tech adapter., This simple box allowed consumers to plug their home phone into the internet where is could then access the VoIP phone system if require for the host of services that were normally not possible. These included queuing systems and IVR’s. It also allowed CPS through IP telephone (Carrier Pre-Selected) which meant that the call wasn’t routed via the incumbent supplier, say BT). So when a call was made, rather than BT billing the customer for the call, the supplier of the Hosted VoIP phone system would route and bill for that call. The added advantage here for domestic users was that these calls, especially for overseas, were much cheaper than standard analogue calls, even when call packages were taken into account. For a business based on Warrington, Saffwood Communications was able to reduce their international spend by 43% due to much lower call charges, no connection fees and lower billing segments.

VoIP systems can connect straight to networks by employing techniques including Ethernet LAN or WAP. The phones are designed and manufactured in the style of traditional units so that the user functionality is similar giving a better customer experience.

We have already discussed an ATA. This is hardware that allows traditional phone systems to connection to IP networks. These are particularly useful for single line businesses or domestic users where the broadband is on the same line.

Again, we have already covered some of the functionality of a Softphone which is an application which can be installed onto a PC, a MAC, tablet device or mobile application. These display a traditional dial pad and will allow VoIP calls to be routed to that device. The cost of these applications is typically low, or free, allowing businesses to take advantage of these technologies for very little capital expense.

Analogue & Mobile Networks

Telecom service operators are more and more turning to VoIP systems over private networks to allow data centre’s to relay calls with more and more service providers. This is now a prevelent activity throughout most of the modern world. Think: when you make a call from a VoIP system, you are sending that call through a series of SIP relay stations across the UK, and indeed the world, to the point that the call needs to ring.

Businesses Usage for VoIP Systems To Maximize ROI

With broadband coming an increasing core element within businesses, this has pushed ISP through government backing to provide faster, more robust services to companies. If you take the “rural broadband rollout: there has been considerable pressure for ISP (internet service providers) to install fibre connections to rural areas that are “technologically isolated”. For main towns such as London, Manchester and Warrington, broadband connections offer ADSL, ADSL2+, fibre, EFM and lease lines. These connections allow businesses to migrate from copper connections to VoIP phone systems to improve efficiency and reduce cost. Post 2008, over 75% of new phone systems were VoIP or SIP. This shows a massive move towards this technology as businesses realize the power of this service.

There are many “flavours” of VoIP systems. A common one is unified communications which harmonizes several applications into one user interface. These are commonly video, voice, email and instant messenger. IT businesses and call centres are drawn towards unified communications as this also offers the presence service allowing uses to see who is on line, and what their VoIP system status is (IE talking, idle etc). The SOHO and small to medium business market have seen particular benefit due to the low charges for setup, no installation fees and low running costs. With hosted VoIP phone systems, a maintainer is not required as the only hardware which is on premise are the phones themselves. For business in and around Warrington, Saffwood offers free setup and free site surveys to ensure that data points (where ethernet cables are house) are close to work stations.

Whilst VoIP systems will allow both voice and data to be transferred over the same network, it is sometime more advisable to have a separate broadband connection for voice, and another for data. The judgment call here is: what do you use the internet for? If it us a smaller number of uses on the system, and the internet usage is general browsing and emails, then a single connection (of average speeds) is typically okay. In the case of heavy usage, thing graphic designers uploading large files, a separate connection is always reccomended

As discussed, cost is a main advantage for VoIP phone systems. A typical ISDN channel connection is £15 per month, and must be bought in pairs of 2 (IE you have to pay 2x £15 even if you need just one extra line / channel). With VoIP systems, you can choose from any number of lines and extensions. For example, you would pay a certain amount for each concurrent call you want to be able to make and receive, then a lower cost for additional extensions. Each extension can make and receive a call as long as one of the VoIP lines is free on the system. Where all lines are in use and a call comes in, most solutions will offer a telephone queuing system.

An advantage to a VoIP phone system is the user interface that acts as the PBX. Think of a PBX as the brain of any system: it decides where calls get routed, if calls should be allowed through (think call barring) – it can even dictate what happens to caller ID’s (IE you could put a certain caller ID, perhaps an important client, directly to a certain extension). With ISDN PBX’s, typically you need an external company or an IT technician to use the software, however with VoIP phone systems, the UI (user interface) is so simplistic, the day to day office worker is more than capable of controlling the system. Common things that can be controlled are: direct dials, incoming call rules, voicemail alerts and much more.

Ensuring a robust service with VoIP

A fundamental concern for businesses when considering a VoIP phone system is: how do I ensure quality of service, and continuous service. After all, the call is being transferred down the internet, what happens if the internet goes down or we lose voice quality? Both of these questions are important, and it is equally important for businesses to understand the risk and danger areas that can be associated with a VoIP solution. The two main areas that will effect an IP call will be: packet loss and latency.

Most routers will deal with data requests based on which one was made first. This means that if a high volume of data and voice requests are made at the same time, say 500 calls being made at once, there isn’t enough processing power and bandwidth to action all these requests at the same time. This would cause backup on the router meaning a delay with information being passed back and tow between callers (you would hear a delay with people hearing what you are saying and visa-versa).

The solution for this in many businesses mind is to attach the VoIP system to a load balancing router. The issue here is that load balancers will split up the data packet (think that a 100K call is in fact containing the codec code for what you have said). A load balancer, which connects a single router to several broadband connections may send 50K down one line and 50K down another line. If these packets do not arrive at the end point at exactly the same time, then the call will become garbled. Manual load balancing is far better, IE have a dedicated line for data (browsing) and another for voice (talking). This means that there is always enough capacity from a router processing perspective and from a bandwidth perspective to handle the amount of traffic.

Traffic can be prioritized with QOS (Quality of Service) Systems for VoIP phone systems. This is effective when a leased line is being used. This would mean the business only has one broadband connection, but this is a dedicated line with 1:1 contention. This is ideal, and common for call centre’s, where their VoIP phone system is likely to be for a high number of users, many of which will be accessing web services and cloud based solutions. A QOS needs to be programmed to recognize VoIP system traffic and identify this as such. This is done by telling the QOS what ports the VoIP service will use. Once the QOS service has this programmed in, if there was a shortfall of bandwidth, then rather than the voice traffic becoming backed up, this would take precedence over data traffic (say a download from a website) so that the voice is transmitted with perfect quality. Whilst this is a robust solution, it is also costly and typically only larger business tend to opt for this solution. Smaller business are unlikely to require this as manual load-balancing will handle that issue with much lower cost.

Other areas of risk for IP telephony systems is fixed capacity. This is where and maximum limit has been set within the local area network (often done by IT managers to restrict total bandwidth usage as this often causes routers to go into an admin reset process). Distributed Denial of Service attacks have been made popular by Anonymous. This is where huge volumes of data requests are directed at a website or network causing is to fail. Thankfully DoS against SME’s in the UK is very rare, but again is an important consideration when thinking about a VoIP system.

When calls are being made internationally, there may be some unavoidable latency, as there would be from any other type of phone, be it analogue or ISDN system. This is down to the amount of exchanges and or switches the call must be relayed over. These can be minimized with a VoIP system by ensuring that the provider only uses Gold and Premium routes for SIP relay. This means that the call is taken over the most geographically efficient, and quality enabled path. Many, seemingly cheaper providers, will use low grade routes that needlessly route calls overseas even when the call is UK to UK. This allows them to access very cheap rates, but the call quality suffers as a result of this. Whilst Saffwood is based in Warrington, we use 6 data centre’s within the united Kingdom, and will only use Gold and Premium routes for our calls.

There are two types of porting codec for VoIP. These are TCP and UDP. Some VoIP system providers use TCP, but UDP is more common. When the amount of data being channeled down and switch is so large that over spilling occurs, TCP will reduce the transfer rate to accommodate this. Whilst UDP does not support this function, users for VoIP phone systems can avoid packet loss by employing QoS as mentioned which will see a large surge of data, then prioritise the voice traffic again of this to ensure that the voice call gets out first and does not end up backlogged behind – which again would lead to latency.

So far in this article, we have looked at how calls are made out. The technology receiving a call plays a huge part in the process too. When an IP packet arrives at a none VoIP enabled phone, then conversion is required to turn the data into something which can be relayed. Several things take place to enabled this including jitter reduction, buffering and codec realignment.

PSTN & VoIP Phone Systems

There is a way to connect PSTN protocol through VoIP gateways. This is a hardware and software connection that allows a PSTN network device to access a IP telephony solution.

The most common example of this is SIP integration. Many businesses with large, existing ISDN phone systems would face initial costs to move to a VoIP phone system. This is because VoIP uses IP enabled handsets to make calls. Phones for digital systems and analogue systems will not work when plugged into an ethernet port. To avoid this issue, SIP was introduced. The most common employment of this is changing an ISDN PBX for an IP PBX. If you recall, a PBX is the brain of any phone system. By swapping a PBX for an IP PBX, you will be able to keep your existing hardware whilst changing to a different solution. This makes sense for large businesses with many handsets. For smaller business, it make more commercial sense to change the handsets as the associated cost for this is much lower than an IP PBS, the csot of which ranges from £1500 – £5000 depending what functionality is required.


Porting a Number to a VoIP service.

Being able to retain a phone number when moving to a VoIP phone system is vital. Businesses with long histories of trading will have an established phone number which they would need to continue to use to allow customers and prospective customers to continue to contact them seamlessly. There are a variety of options and advantages for businesses looking to move their phone number to a VoIP system. The process for moving a number is also straight forwards. At a glance the new VoIP service provider will make a porting request to the losing part for the number/s. Once done, the new service provider will need to setup routing to enable the number to “migrate”. There is no downtime or disruption with this process when exercised correctly.

Sometimes numbers cannot be ported. This can be that due to the fact that the new / old service provider do not have porting agreements. This can be true when trying to port one VoIP held number to another VoIP provider. In most cases, even if the number is hosted by an IP telephone provider, the range hold is still typically BT, Virgin or Talk Talk (the main UK carriers).

Where businesses, or consumers only have one line with broadband on it, this presents a challenge for a VoIP phone system provider to take over the number. This is because when a number is ported, the line it has been ported from will cease (you can’t have a phone line without a number). Where the line is only being used as a phone line, this is not an issue as the VoIP line will have picked up the number at the same time. Where the line carries broadband, dropping the phone line will also terminate the broadband service. The two proven methods to resolve this are

  • Setup a new phone line and broadband service, then port the number leaving the new line carrying the internet
  • Place a caller diversion from the main analogue telephone line onto the VoIP phone systems main number. This works better when the line being diverted from has an unlimited call bundle for local calls at it avoids a call charge for diverting the call. Even if 50 calls are made at the same time to the analogue line, all calls will be passed to the VoIP system where is can be handled and if required queued.

Caller ID Presentation with VoIP Phone Systems

With a traditional phone the caller ID it will typically display the telephone number associated with the line. Some services offer to make the caller ID anonymous. With ISDN phone systems, you are able to pay to change the caller ID, or Caller Line Identity Presentation (CLIP). This is typically used for businesses that need to display a non geographic number (NGN) such as an 0800 or an 0845. These businesses tend to operate nationally rather than in a local area. With a VoIP phone system, you are able to set your CLIP to any number you wish. There are rules and regulations as to what number you can and cannot display when using VoIP in this method. Firstly you must be the owner, responsible for, or related to the number that you are displaying from the system. For example, you would not be allowed to display a number for another business as this would be classed as Spoofting.

There are also other numbers that reputable VoIP system providers will be wary of displaying due to their association with scamming. Most notably amongst these are 070 numbers and 090 numbers as both are high revenue generated or premium rate numbers.

Some specialist providers, such as Saffwood Communications in Warrington, are also able to provide multiple local and national numbers on one system. This allows businesses with a national presence to establish a local presence throughout the UK. The challenge is then, when you are ringing out, what CLIP do you present? This is where CLI localization comes in (caller Line Identity Presentation). This will detect the local area that is being dialled, for example 01925 for Warrington, or 0161 for Manchester. When it sees the area code being dialled, it will then present the assoicated phone number for the VoIP phone system for that area. So for example, if you had 01925 123456 for Warrington, 0161 123 4567 for Manchester, when dialling a Warrington 01925 number, you would display 01925 123456 as the caller ID, and when dialling and Manchester 0161 number, would present 0161 123 4567. Naturally you would need a valid phone number for each geographic area, but a VoIP provider such as Saffwood would be able to help you in identifying your top calling areas so that you can focus on getting DDI’s (Direct Dial’s) for those area.

CLI localization is a specialist product and is not available on standard phone systems.

Fax support With VoIP

Support for fax has been problematic in many VoIP implementations, as most voice digitization and compression codecs are optimized for the representation of the human voice and the proper timing of the modem signals cannot be guaranteed in a packet-based, connection-less network. An alternative IP-based solution for delivering fax-over-IP called T.38 is available. Sending faxes using VoIP is sometimes referred to as FoIP, or Fax over IP.

Running a reliable service for fax over a VoIP service has been dogged with issues from the conception of voice over IP. The reason is the most codecs used for IP telephone have been geared toward the transference of a voice rather than a modem signaled packet related data (different than voice packets which we have discussed). By using t38, sending a fax to a VoIP line is possible. What is required however is what is known as fax-to-email where the data is converted to a PDF in transit and then emailed as an attachment to the elected email address.

There are several issues when trying to port standard fax numbers to VoIP fax to email. The main issue is that certain carrier will support this process, but if the number being ported has come from a none supportive carrier, this can cause complications when transferred. In most cases, a new fax number would need to be provided. The other living with it challenge is that numbers supplied as part of a sequential range block cannot be used for Fax. This is due to the way that the numbers are handed out by the global registrar (IE they are set for voice traffic only and not for fax).

Powering Your VoIP Phone System

Analogue telephones draw their power from the phone socket which in turn is powered from the national electricity grid. Even if you internal electric circuits fuse, in many cases your analogue phones will still be active as they get the power from the exchange.

VoIP phones must be powered by mains as their connections are either an Ethernet cable or a power cable into mains supply. Ethernet cables, or RJ45 cables, can also provide POE (Power over Ethernet).

For POE, you will need a POE switch which all the LAN cables can go into. These then provide the power down the LAN connection. The advantage here for VoIP phone systems which are larger in size is that less power sockets are required and also there is a cost saving as less power cubes are required for the IP phones.

Failover & Redundancy

It is important to ensure that your VoIP phone system provider has suitable redundancy, also known as fail over. This typically means that wherever and however they are hosting your solution, (in the case of hosted VoIP) – that if their kit fails, they have backup. Saffwood in Warrington as an example as kit in 6 data centres over the UK. This means that if the kit fails, or the data centre has an issue, then there are other data centres ready to pickup the load and traffic. Failover and redundancy does not end there. As covered, when a VoIP call is made, it is relayed over SIP providers (effectively the carriers of the call). SIP carriers can have issues due to load (too many calls) and can also fail. If this is the case, and the VoIP system provider does not have other SIP carriers, you will not be able to make phone calls. Saffwood based in Warrington has multiple carriers to ensure that if one has an issue, there are others that can take the traffic.

Other resources


Saffwood Communications is a Hosted Telephony provider to businesses. We specialise in SIP and VoIP. Our aim is to support businesses using outdated systems such as PSTN multiline and ISDN to move onto modern, robust telephony platforms. We support business of any size and are fanatical about customer care

Posted in CLI localisation, Failover & Redundancy, Hosted Telephony, VoIP, VoIP Phone Sysetm, Warrington

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