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The ADSI VoIP FAQ is a collection of some of the most common questions.

If you’re unable to find the answer to your question or if there are any questions that you feel should be included in our FAQ then please email us with your suggestions on

Q: What Is VoIP?

A: In its simplest form, VoIP uses the internet to make a call instead of the traditional telephone network

Q: Why should I switch to VoIP?

A: Because VoIP is a hosted service, there are a range of features that may not be available as standard with a traditional phone line. From Hunt Groups to Availability Profiles, Instant conference calls to Busy Lamps, Automatic Schedules to Number twinning, there are a number of features available within the core system.

Q: Does hosted VoIP have any disadvantages?

A: VoIP is not perfect, and as such there are a few associated problems that need considering in comparison to traditional telephone service.

  • VoIP desk phones will not work in the event of a power cut, however these will default to disaster recovery rules such as forwarding to mobiles.
  • VoIP can suffer problems with call quality when not using an assured data service

Q: What is the minimum required to run VoIP?

A:  In order to have a working system, three main parts are required:

  • An internet connection capable of supporting the VoIP traffic
  • A subscription per user
  • A VoIP phone – This can be a physical IP phone, a PC client or a smartphone app.

Q: What are the bandwidth requirements for VoIP?

A: A VoIP call only requires 200Kbps of a sustained bandwidth for high quality calls, or 80Kbps for landline quality calls. You can quickly evaluate your connection with a free broadband speed test.

Q: How good is the VoIP call quality?

A: The quality of a VoIP call will be dependent on who you are calling, call a mobile, and you will receive a mobile quality call, call another VoIP phone however,  and you will receive a better quality of call.

Q: Is there any difference in making a call with VoIP?

A: As an end user, there should be no perceived difference in making a standard call, just pick up the handset and dial.

Q: Is there any restrictions on who I can call?

A: As with a normal phone, you can call anywhere in the world. However, the system does have the ability to block call types (such as international calls, premium rate etc.)

Q: What about receiving a call?

A: As with making a call, this is the same as a traditional phone system, simple pick up the ringing phone. If you are using a soft client, you will need to have your computer/mobile on and the soft client open in order to receive the call. Then you just have to click to answer.

Q: What is a Soft Client?

A: A soft client allows you to use an app on your smartphone or a program on your PC to make calls as if you were using your desk phone.

Q: Can I use my phone abroad?

A: Typically, so long as you can connect to an internet service that provides the required bandwidth with an RJ45 port, your phone will work abroad as if you are back in the office. For even easier access, the PC client will work wherever you can connect to the internet too!

Q: Can I port my number to VoIP?

A: Yes, you can transfer over from any provider that has a porting agreement in place.

Q: What if I move?

A: Hosted telephony works via the internet rather than being tied to your local BT exchange. Because of this, your phone will work at any location that has high-speed Internet.

Q: Anything to watch out for?

A: There are a few services that are incompatible or require additional products to enable their operation, such as:

  • BT Redcare Lines
  • Fax Services
  • Loud ringers/Paging systems

Q: Why should I choose ADSI VoIP?

  • Privately owned and debt-free, we have established ourselves as a leading Telephony services provider.
  • Hosted in two geographically (soon to be four) diverse redundant data centers.
  • Premium features included in the core package.


  • ‘We are very happy with the handling of our account.  Our Account Manager always deals with any queries and requests very promptly and efficiently and, importantly, we feel confident that we are kept informed of the best options for us.

    From comparisons we have made we do believe that we have saved money and would have no hesitation whatever in recommending ADSI to business colleagues.’

    Boshers Cholsey
  • ‘Corniche International have been using ADSI for all our telecom needs and have always found their service to be professional and friendly and the team are always there to help. We will carry on using ADSI for the foreseeable future’

    Corniche International
  • ‘Our Account Manager worked really hard at sorting our an almighty mess created by Carphone Warehouse, it’s great to have one point of contact and be able to have somebody who is prepared to take ownership of any problems that occur. ‘

    Capital Drainage
  • ‘I was dealing with one of your colleagues a couple of weeks ago regarding a fault with a new phone, I just wanted to say that they were brilliant, really efficient and got things sorted quickly’

    Johnston Mailing
  • “I would like to thank ADSI and our account manager. They have been great in finding the best deal for us and although we are a very small part of your business we have felt like our queries and concerns were being listened to and dealt with quickly. We look forward to continuing our relationship with ADSI”

    The Helpful Bureau
  • “Always been very happy with ADSI from day one. We get contacted constantly by other companies but we would never leave ADSI as the service is fantastic and our Accounts Manager is brilliant – he helps with all queries and is knowledgeable, friendly and  we feel confident that he  gets us the best deal. Many companies we’ve used over the years have been in it for the money only but with ADSI we feel that they really do put the customer first, can’t praise highly enough.”

    East Durham Community Transport
  • “Our account manager makes this otherwise stressful task of the comms pain free. We receive a personalised service and he is always on hand to advise us on maximising our telecoms whilst keeping an eye on budgets, all without compromising the high level of standards we have come to expect.   Because of this we have moved all our mobile needs to ADSI which goes against normal company policy where we by principle never use a sole supplier.”

  • “I would just like to thank you for all your help over the last couple of months. I admit that I was hesitant at first but the service level of ADSI, your professionalism and expertise has been second to none. I would not hesitate to recommend your services to other business colleagues I know. I look forward to our on-going working relationship.”

    AM World UK
  • “We are really happy with overall service from ADSI; it’s great to have someone assigned to our account that can help us with any issues. Our overall phone costs have greatly decreased and we are extremely happy with ADSI.”

    McCue Corporation
  • “My Account Manager is extremely good at alerting us to areas where we could potentially save money within our business. We are more than happy with the service we receive from ADSI & I would strongly recommend them to other individuals or businesses.”

    Trans XL
  • “We have dealt with ADSI now for approx. 5 years, and have been continuously impressed with the good old fashioned level of customer service. Not only do they keep their eye on our account to make sure it’s the best value for us and offer us great deals on new products, but the back-up is second to none. I would have no hesitation in recommending them to business colleagues. Keep up the good work!”

    Pink Scaffolding
  • “ADSI offer a personal service delivered in a very professional way.  I am very satisfied with the service and support provide by ADSI.  I am confident that when I call, my questions will be answered without delay and this is delivered at a very competitive price.  ADSI look after their customers be providing a pro-active service that will let me know if I need to make any changes to my mobile account.  I am free to concentrate on other aspects of my business because ADSI are looking the mobile accounts.”

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