This guide should help you start asking questions of the business needs for video conferencing, and indeed choose the best infrastructure to meet you conferencing requirements. |
Network Infrastructure One of the first things companies should consider when choosing video conferencing is the type of network they want to run the video packets over. There are typically two ways to video conference which are video over ISDN or video over IP. |
Video Over ISDN ISDN is the traditional method used for video conferencing. To video conference over ISDN you will require between 2 and 4 ISDN2 lines. (ISDN30 in 64k format cannot carry video packets unless your PBX can ‘bond’ two lines in 128K pairs – this can often be done using an s-bus card that plugs into a PBX, however each PBX manufacturer may do it differently.) When considering using ISDN for video conferencing you need to weigh up two things: |
1) Cost 2) Packet loss/Stability 1) The cost to install ISDN lines is typically £249 per line. There is a monthly line rental charge of about £24 per line. A typical installation will consist of between 2 and 4 ISDN lines. Call charges associated with using ISDN lines may vary depending on your provider. We provide ISDN lines at wholesale prices to ensure customers can benefit from rates that are typically 80% below those of BT retail (see article). |
A typical one hour UK to US video call will cost around £18: a UK to national call will cost about £6 per hour. 2) ISDN is the traditional method for video conferencing and it is still predominately used by many organisations. Since video packets over ISDN do not travel along the same exchange as IP packets (internet Protocol) the risk of the ‘bottle neck’ effect is eliminated and all packets sent from the far end site arrive at the near end site quickly and in the correct order. (Packet loss occurs when video packets do not arrive in the correct order which can cause the image to freeze or become blocky.) Video over ISDN is in most cases the most stable way to video conference. It is worth noting that ISDN based video conference systems require a bridging facility to communicate with IP based video conference systems and vice versa. We offer full managed and unmanaged bridging facilities. |
Video Over IP Video conferencing over IP is fast becoming common place in organisations. There is one overwhelming reason for this change: that is the cost to increase IP bandwidth capacity has been falling and still continues to fall. |
There are 3 main levels of service (DSL, ADSL, SDSL) available which offer different quality of service and bandwidth capacities, with DSL being the lowest and SDSL being the highest. We recommend SDSL for video conferencing. Most companies have some internet connection and can run video conferencing without upgrading. We usually advise companies considering using video conferencing over IP to look at their network usage over the past 12 months and consider future increases/decreases and operational changes that may affect bandwidth usage. Each case may vary depending of usage but as a rule of thumb we recommend a provision of 1.5Mbps to 2Mbps be set aside for video conferencing. |
The stability of a video conference over IP is dependent on many networking factors including size and stability of bandwidth for both yours and the far site’s network. For more information about video conferencing over IP please contact one of our networking specialists. |
Cost There are no call charges associated with using video over IP, unless you connect to an ISDN based video conference system. You will be charged for connection to an ISDN gateway; typical ISDN gateway connection charges range from £60 – £160 per hour depending on level of service, connection speed and operator. |
Bandwidth Requirements – now & in the future For both IP and ISDN networks you will need to consider who you will be conferencing with on a regular basis. Ideally you will have the same type of network as other sites within your group. We provide bridging services to allow you to conference with IP from ISDN and vice versa. Once you have decided on your network you will need to consider what features you want from a video conference unit. |
Hardware Functionality In general there are only really two add on options to consider: Multi Point capabilities (connecting with you plus two or more sites) and People & Content (sharing presentations, PowerPoint, spreadsheets etc. within the conference). Since systems ship with the ability to share presentations IP to IP multipoint upgrade is often the only choice. |
We are sure this snippet of information will not be enough for you to make a purchasing decision but hopefully it will help raise some questions that aid your decision making process. We have a host of facilities available including on site demonstrations and test calls. For more information or to book a demonstration contact our customer services team on 08458 380562, use the contact form or email cs@videoconferencinglondon.co.uk |