VoIP Handsets

For cost effective call transfer from our Virtual Switchboard service PhonePresence, we recommend the use of VoIP handsets. Calls transferred by PhonePresence to VoIP handsets, that are registered with us, are free as part of the service. VoIP handsets require a fixed (as opposed to dial up) internet connection (at least Broadband). PhonePresence do not provide support for the handsets you source or your internet connection but can make recommendations as follows:

Free IP phone download - X-Lite soft phone Xten.com can be used but only when there is plenty of bandwidth available (it only supports G711 codec, see below). In other cases you must use X-Lite Pro with G729 Codec. Can be used with a headset. Budgetone handset available from Voiptalk.org or from us. Snom available from Snom.com or Voiptalk.org. After signing up to PhonePresence, registration settings will be given to you by our technical team. Technical Support will be provided for the handset registration process. You will then be able to list your IP handset against your PhonePresence user ID so that PhonePresence will target your handset with any calls for you. As a result of handset registration, you will also be able to sign up for our VoIP Outbound call service which gives you access to our great outbound rates. Please apply for specific destinations and/or a full rate card. Please apply to the Sales Department for specific advice on bandwidth requirements but generally, a broadband connection (of 500kb/s and above) will suffice for up to 3 users, for more, we recommend a 1 Mb leased line. If your business activity involves using bursts of internet bandwidth for some purpose other than telecoms, you may wish to invest in some equipment, or software, that partitions, and therefore protects, the bandwidth required for the voice traffic.

:: Budgetone 101 :: :: Snom 190 :: :: Snom 360 ::

Otherwise, generally, most businesses will be able to use the service without extra equipment and sound quality will therefore be guaranteed within the realms of assumed perfect internet network conditions (i.e. ultimately reliant on network conditions).

A common question asked is regarding the bandwidth needed for VoIP traffic. This depends on the amount of compression used in the voice signal which affects the quality of speech. X-on uses either G711 A-Law or G729 A ‘Codecs’ which are compression standards. G711 is the higher quality and requires more bandwidth. The G729A compression gives perfectly acceptable quality (ask your sales representative for a sample conversation) and will be supplied as standard since it uses less bandwidth. In fact, you only need 24kb/s per conversation for G729, so in theory you will be able to have over 40 conversations on a 1Mb leased line. In practice, the amount of other data traffic will affect how much is available.

If you have a broadband connection which is contended (shared with other users) you will need to make allowance for this and also the fact that an ADSL connection is asymmetric, so you need to use the upload bandwidth rather than the download when calculating how much is needed.  In some circumstances, you may be able to preserve the bandwidth available for VoIP conversations by using a router that gives priority to this traffic over other traffic.

The VoIP quality on International calls is subject to the internet connection between the UK and client location. This will vary with time of day and the contention ratio of your local provider. Softphones such as X-Lite, which only provide non-compressed (G711) VoIP, use a lot of bandwidth and hence are more susceptible to packet loss. The G729 codec, which is available on the professional version of X-Lite and on hardware phones such as the Grandstream Budgetone and GX2000, is more compressed, uses less bandwidth, and hence should be less prone to packet loss.

From this brief summary, it can be seen that it is difficult to recommend and certainly guarantee quality of service with particular connection types, because of the environmental factors concerned. However, from practical experience in most circumstances, an ADSL broadband connection of 512k will allow a minimum of 3 users to converse simultaneously. If you are also a heavy data user, or intend to have more than 6 simultaneous conversations, we would recommend that you have a 1MB uncontended leased line.

For further information on X-on VoIP and how it can benefit your business
please use our Contact Form or call 0870 345 5577.