An Integrated Services Digital Network (ISDN) is a telecommunications technology that enables the transmission of digital data over standard phone lines.
With that being said, it can be used for voice calls as well as data transfer.
Also, it can operate over copper based systems and allows the transmission of digital data over the telecommunication networks, typically ordinary copper based systems and providing higher data speeds as well as better quality than analogue transmission.
Therefore, ISDN specifications provide a set of protocols that enable the set up, maintenance and completion of calls.
ISDN, Integrated Services Digital Network, provides a number of significant advantages over analogue systems.
As a result, it enables two simultaneous telephone calls to be made over the same line simultaneously.
Hence, faster call connection. It typically takes a second to make connections rather than the much longer delays experienced using analogue based systems.
Seems like, data can be sent more reliably and faster than with the analogue systems.
So, noise, distortion, echoes and crosstalk are virtually eliminated. Sounds great?
Furthermore, the digital stream can carry any form of data from voice to faxes and Internet web pages to data files – this gives the name ‘integrated services’.
How to connect your existing phone system to the NBN
So, the NBN is being installed into your area and Telcos are sending you baffling information about what to do.
Some (most) will say that you need to change your telephone system as yours is not compatible with the NBN. This is not true!
Some (most) will say that you must connect up to the NBN now because your telephone lines are going to be cut off immediately. This is not true!
The people that tell you this are simply trying to make a sale. They do not care what they sell you and it will generally be someting that does not suit your business requirements. We are sick of these guys trying to force businesses into spending money on something that they do not necessarily need.
Have you been looking for a good explanation about VoIP??
Well here is what you are after….an explanation of VoIP without too much techo babble and not trying to sell you anything.
There are way too many myths about VoIP, where it is going and what it can do for your business. We are passionate about you getting the right information to you. We will probably upset some other providers but you should have all the answers before you invest in a phone solution.
Note: this section is mainly focused on VoIP for business, although the basics of voice is the same for residential. We will update this in time.
So, what is VoIP?
Traditionally, your land-line voice calls get from your house or work to the called person via a pair of wires that connect your place to the local telephone exchange. The call then goes across the telephone network to the called person’s local telephone exchange and then a long a pair of wires to their premises.
Voice over IP works by sending your voice (telephone) call across a data network (i.e. the Internet or a private data network). Now, IP stands for Internet Protocol and is the method used for sending data such as emails and other files between PCs and/or across the Internet.
IP works by dissecting the data (say, an email) into small blocks of data, then adding the recipient’s Internet address information to these blocks of data so they are ready to be sent out onto a network. The network devices that form the Internet (or private data network) determine where to send these data packets based on the Internet address.
Similarly, for a voice call your speech is digitised (much like music on a CD is digitised) so it is now data, and dealt with the same way as other data (packetised, addressed and sent).
The difference with a telephone call across a data network compared to sending an email is that the voice call needs to be ‘real time’. You don’t notice if there is a one or two second delay when receiving and email…but get those delays during a VoIP telephone call and the voice data starts to break up and “it sou-nds l-i-k-e th-is!”.
IP was designed for data files…not real time voice conversations. Sometimes within a network the data packets can go missing (if they become corrupted the network devices will simply dump them) and so there are mechanisms built in to tell the sending device (i.e. PC) to resend a packet because the receiving device did not receive it.
This recovery mechanism does not work in a real time situation (i.e. a VoIP call). There is not time to stop mid-sentence (or mid-word) to wait for a missing bit of data to be re-sent.
These are the challenges that VoIP faces…and is the reason why many people have all sorts of problems with a VoIP service. VoIP can be built to work quite well, but needs to be designed and implemented correctly to ensure that it is acceptable.
What are the benefits of VoIP?
By implementing VoIP a business can take advantage of a number of rather cool features, such as:
- Voice-mail to Email
- Remote Workers )i.e. phone extension at home)
- Possible cost savings (see below for more on this)
- Adds, moves and changes to handsets can be cheaper
- Can share data cabling with PCs (but not recommended…read on)
If you are thinking of moving to VoIP it is worth analysing what the drivers for this are. Below we talk about costs & savings associated with VoIP. We also look at VoIP system configurations as there are a number of ways of implementing VoIP.
What are the disadvantages of VoIP?
For all the hype that is out in the market place saying that VoIP is the best thing since sliced bread, it certainly does have its disadvantages. It is worth taking these factors on board when determining whether to move to a full VoIP solution.
Disadvantages of VoIP are:
- Occasional quality issues as described above
- Phones require external power (either power pack or special data switches means additional point of failure)
- VoIP Handsets are generally more expensive than other phone system handsets.
Can I save money with VoIP?
The short answer is ‘Yes & No’. VoIP providers will sell their wares by saying you can save up to 50% on your call costs by using VoIP, but let’s analyse that a bit closer.
Line rental for a VoIP service is generally cheaper than a fixed line, but remember that the Internet connection needs to be far greater in speed to accommodate voice traffic. If you only have 2 or 3 lines then this is not generally an issue as a good ADSL2+ connection will suffice. Any more lines than this and you are probably best to have a dedicated Internet link for voice traffic, which can often be more expensive than normal line rental. So, for residential and very small business, this is where you can save money on line rental…not necessarily so for larger businesses.
Local and long distance calls are generally cheaper and unlimited. This is well and good if you make many of these types of calls and the average call length is quite long. What most businesses fail to realise is that the majority of their costs are calls to mobile phones, and most VoIP providers do not have very good rates for these call types. A good analysis of you your call types is needed to ensure you choose the best option.
Suppliers of VoIP phone systems say you can save money on cabling costs by having one cabling infrastructure and/or sharing the same data connection between the phone and PC. In the old days you ran one type of cable for data and another for voice. These days phone systems generally use the same cable type and go back to the same patch panel…so, in reality, there is only one cabling infrastructure.
Sharing a data cable between PC and phone is not always a good idea. A phone is predicatable as to what it will send out on a data network…i.e. a 64K data stream of digitised voice (plus the UP addressing, etc.). A PC may sit there idle or be sending/receiving large amounts of data, or it may go haywire and start sending all sorts of rubbish out onto the network…hence it’s data usage is unpredictable.
If the network is being shared between voice and data then problems occurring with PCs can cause telephony problems as well (bad quality or loss of phone system). One PC having issues can bring down the entire phone system. Any reputable (and knowledgeable) VoIP supplier would put the Voice and data traffic on separate data networks.
What is the best way to implement VoIP?
There are 3 VoIP components to look at here:
- VoIP Lines
- VoIP main system
- VoIP handsets
VoIP lines may save some money but this needs to be analysed carefully as discussed above. There is a good chance that you will better off using digital ISDN lines (see How to choose Telephone Lines page). Another suggestion would be to use traditional lines for certain call types (i.e. calls to mobiles) and also have some VoIP lines for other call types (i.e. long distance calls). Most phone systems have the ability to automatically select a particular line based on the number call.
VoIP Telephone Systems
There are 3 types of VoIP systems marketed out there in the Telephone System world (so be aware):
A traditional digital telephone system that has had VoIP functionality added to it so they can say they do VoIP (and a lot of times they do not do it very well). A full IP telephone system that has VoIP lines and VoIP handsets (and to connect anything else like standard lines you need additional boxes which leads to more points of failure). A VoIP Hybrid telephone system that can cater for VoIP, PSTN & ISDN lines and VoIP, digital & analogue handsets out of the one cabinet (= more functionality and less points of failure).
A VoIP Hybrid system such as the Alcatel OXO or Avaya IP Office can perform all the functions of a VoIP system yet it can have both digital handsets and/or VoIP handsets. These phone systems can also cater for PSTN lines, ISDN lines and VoIP lines without requirring additional external devices like most pure VoIP systems need (hence, less cost and less points of failure). This is by far the best option for a business. Even if you plan to send all calls out via VoIP line, it would be wise to have some PSTN or ISDN lines as backup, as they are far more stable than VoIP lines.
VoIP handsets require data cabling (even though the speed required for a voice call is a fraction of the network speed) and also require external power, whereas digital handsets are powered from the phone system and can work over data cable or speaker wire if they have to. So to move from traditional phone system to pure VoIP unit it is generally required that all cabling for the handsets is replaced with new data cable (which can be a huge expense). It is the phone system and not the handset that performs all the advantages of VoIP as described above. On the Avaya IP Office for example, the VoIP handsets and the digital handsets look exactly the same and have the exact same functionality…however the VoIP handset is more expensive. A good VoIP solution can be implemented without necessarily going VoIP all the way to the handset…there is no real advantage in doing this.
Do you think about the drivers motivating you before moving to VoIP.
Cheap Call rates and line rental – analyse this carefully, or get us to do this for you.
Unified Communication and other VoIP features – good idea but do you really need to go VoIP all the way to the handset? Remember, there is no added advantage to this just cost.
Open choice of handsets – some people like the fact that they can use any SIP handsets on an open type system. This is cool but you are now limited by SIP itself. A lot of systems have some cool features that are specific to the way they communicate to the main system. These are not neccassarily available with any SIP device.
Less cabling costs – yes you can share the data cable between PC and phone but sometimes the initial cost of additional cabling is better than the pain this can cause further down the track.
As mentioned, VoIP can and does work if designed well. We use it ourselves, but are very cautious as to where and how we implement it, as we do not want customers to have a bad experience due to bad decisions.
There is a good chance you’ve experienced poor call quality if you are currently using a VoIP phone system. In this article, we will be discussing the common causes of VoIP call quality issues and what can be done to correct them.
It is simple to diagnose the causes of poor VoIP calls and to find a solution to the problem. Once fixed, these issues should not be ongoing, otherwise you may need to switch to a different VoIP service provider.
Latency (also known as VoIP delay) is characterized as the amount of time it takes for speech to exit the speaker’s mouth and reach the other person’s ear; when the level of latency is too high on a VoIP call it will produce an echo. There are three types of delay commonly found in today’s VoIP networks.
- Propagation delay – In propagation delay, light travels through a vacuum at a speed of 300,000 kilometres (186,000 miles) per second. Electrons travel through fibre or copper at approximately 201,168 kilometres (125,000 miles) per second. A fibre network stretching halfway around the world (20,900 kilometres) produces a one-way delay of about 70 milliseconds. Although this delay is almost undetectable to the human ear, propagation delays in conjunction with handling delays can cause evident speech degradation.
- Packetising & Handling delay – Packetising is where the speech is digitized and divided into
- IP packets for transport to the remote destination. Handling delay is caused by devices that forward the frame through the network. Handling delays can affect traditional phone networks. However, in packetized environments, these delays are a larger issue.
- Queueing delay – Due to congestion on an outbound interface, packets are held in a queue, resulting to queuing delay. Queueing delay ensues when more packets are sent out than the interface can handle in an interval.
The solution for this issue is to prioritise VoIP traffic over the network which yields latency and jitter improvements. Widely used techniques for prioritising VoIP traffic are bandwidth reservation, policy-based network management, class of service, type of service, and multi-protocol label switching (MPLS). A quality VoIP router can resolve several of these issues and can result in business quality VoIP phone service.
Jitter is a common problem of packet switched networks and connectionless networks. The information is divided into packets. Every packet can travel through a different path from the sender to the receiver. When they arrive at their anticipated destination in a different order than what was originally sent, the outcome is a call with scrambled or poor audio.
It can be difficult to identify what the exact culprit is, since we are using internet connection to make phone calls and send voice data. But the most common causes are:
- Wireless networks – While a wire-free network enables mobility, freeing us from seeing cables all over the office, there will be times when we can experience degraded network connection. Wireless network works well with mobile devices, but not dependable in making phone calls.
- Network congestion – The most common and obvious cause of jitter is an overcrowded network. If too many devices are connected to the same network and are being used at the same time, bandwidth will surely run out and will slow your connection to a crawl. This leads to insufficient bandwidth when making a VoIP call and packets being delivered out of order or dropped.
- Bad hardware – At least a modem and a router make up our internet network, sometimes switches as well. Bad hardware, such as an outdated modem, a misconfigured router, or a damaged Ethernet cable can lead to call quality issues.
Using jitter buffers minimises delay variations by temporarily storing arriving packets. However,
a large jitter buffer will increase the amount of delay. Packets that arrive too late get discarded.
- Internal network inadequately configured
If your company has decided to route both data and voice over the same network without properly setting up your network for VoIP traffic, you can expect to have issues with the quality of your calls. Proper network configuration is the solution for this problem. This is, in fact, one of the least expensive and easiest problems to correct. A router capable of Business VoIP that is properly set up will generally fix this issue.
- Inadequate equipment
Old or defective equipment can create impedance. Other things that contribute to poor VoIP call quality are outdated routers, cable modems, and firewalls. Examine each network element between your computer, VoIP device, and the internet to isolate the issue. Update your router software or better, replace current equipment with new ones.
Many small businesses use their internet connection for both data and voice, which is fine as long as the router has the capability to prioritise VoIP traffic. Call quality can be affected by other users on your network if you do not have a router that is configured for packet prioritisation. For example, another user on your network downloads a large file while you are on a call. Without packet prioritisation, the call’s quality could be degraded. A VoIP router prevents this from happening by giving priority to your network’s voice traffic.
- Poor internet connection
Most ISPs are not design for VoIP. Transporting voice packets is different from simply surfing the web; it requires an additional set of internet protocols possibly not provided by your ISP. You will need to contact your provider and ask if you can upgrade to business class high speed. Fortunately, most cable and DSL high speed internet providers offer business class high speed that is acceptable in making VoIP calls.
Candour Communications has developed a Telephone Lines in a Box product, making your VoIP lines less reliant on the type and quality of your internet connection. You won’t have to worry about quality issues that can be experienced with your current VoIP lines.
Telephone Lines in a Box uses its own data connection via our Enhanced Voice Gateway, so voice quality is always assured. To know more about what Candour Communications can offer you, give us a call at 1300 651 350 or email email@example.com.
Pros and Cons
The main advantages that a cloud-based phone system has over traditional phone systems are:
- Only need a broadband Internet connection to start making calls for your business.
- Usually results to cheaper phone bills.
- VoIP doesn’t require expensive hardware as mentioned earlier.
- Cloud-based phone systems are portable and accessible through mobile applications on smart phones.
- There are some upfront costs in getting the proper equipment setup. However, these costs are quite small compared to the money that your business will start saving.
- Your broadband connection affects that quality of your phone calls. If your Internet connection is currently somewhat shaky, your call quality could be bad or may drop a lot of calls. We can certainly assist you with Internet Connection.
- These systems are quite simple and intuitive and shouldn’t take too much time for you and your co-workers to learn.
Please contact us at Candour Communications if you are not quite sure or are ready to upgrade your phone systems by filing out our online contact form or call us directly on 1300 651 350.