Hardware requirements when using Skype

I want to run BroadcastByPhone autodialer using as many Skype lines as possible. What is the hardware requirement? and how many lines can I run?

Bandwidth Requirement

128 Kbps upstream and downstream per line.

According to Skype, each instance/line requires 3-16 Kilobytes per second. This should be both upstream and downstream since voice is two way communication. Normally the limitation is from the bandwidth of your internet connection. For example, if you are using a basic ADSL with 1.5 megabits per seconds downstream and 512 Kilobits per seconds upstream, you can normally run 4 Skype instances (512/16/8 = 4, one byte is 8 bits).

Memory Requirement

70 Megabytes per line

Each running skype instance uses 60M RAM, and 10M for Voicent program, so you have a total of 70M. It is strongly recommended to have enough physical memory for your computer. Otherwise, the performance will suffer greatly. For a 32-bit operating system like Windows XP, you can have a maximum of 4G memory. So if you get the maximum 4G RAM for your computer, there might be 3G for skype instances (1G for Windows itself and other applications). With 3G, you might be able to run up to 40 Skype instances/lines.

CPU requirement

The CPU requirement largely depends on the number of lines used. But it also depends on the usage of speech recognition, text-to-speech, and caller interactions. The more CPU power you have, the better the audio quality and responsiveness. For example, if you use a 4 line system for autodialing, you can use a Pentium Duel Core CPU. For a 10 line system, get a Quadcore Pentium or Xeon CPU. For more than 10 lines, it is strongly recommended to get computers with duel processors and each processor with Quadcore CPU.

Additional Requirement for predictive dialing

Predictive dialing (AgentDialer) requires a lot more CPU and bandwidth than auto dialing (BroadcastByPhone) does. This is because the call transfer mode is different. For predictive dialing, the call transfer has to be done immediately. Otherwise, the person answering the phone will hear dead silence or ringback when the call is being transferred. In most cases, a screen popup is used for predictive dialing, and the call audio is redirected to an agent’s computer immediately. The server computer has to redirect the call audio in real time to and from the outbound skype line and the agent’s computer, thus requires more bandwidth and CPU processing power. On the other hand, for autodialing, a call transfer can be accomplished by Skype to a landline phone or another Skype account. Once a call is transferred, the Skype line is freed and the server can continue with the next call.

For predictive dialing, if an agent’s computer is not on the same local area network (LAN) as the server computer, then additional bandwidth of 16 Kilobytes per second is required for the agent. The is because the audio has to be transferred to the agent’s computer using the same internet connection.

Other requirement

It is strongly recommend to get Windows XP instead of Windows Vista. Due to the security limitations on Vista, you must run each Skype instance in a different Windows Login session. This is time consuming to start and hard to control.

It is also recommend NOT to run each Skype line to its full capacity if you use Skype’s unlimited subscription. Otherwise, you Skype account might rish being blocked by Skype.