Monday, 10 April 2017

Bandwidth and Storage Requirements for Voice and Screen Recording in a Contact Center

We have recently been asked by a contact center to calculate the local network bandwidth and the HDD storage needed for implementing the PhoneUP Voice and Screen Recording solution for 300 agent seats.

Imagine 300 simultaneous audio/video streams recorded 18 hours a day (the agent utilization rate is 75%) 7 days a week and then stored for 1 year. Let’s neglect the voice part as the major load on both the LAN and the HDD storage is produced by the video (screen) recording.

Well... the most used screen resolution is 1366x768 (by w3schools) which is (roughly) corresponds to 720p movie format. And as we all know the file size per hour of 720p movie is about 2Gb. With this in mind thinking about 300 video streams recorded 18x7 could make your hair stand on end. But it’s not that bad.

Let’s examine parameters which influence the size of a screen recording video and how they can be optimized in the case of agent screen recording.

1.       The codec.
PhoneUP uses H.264 and here’s the first major saving. The movie we mentioned above is whole dynamic – every part of it constantly changes throughout the film. But contact center agents usually don’t watch Youtube when talking to customers. They work with CRM instead and that means that 95% of the screen is static, the only part that changes is where the agent, say, types the customer complaint (or selects an item from the drop-down list, or pushes a button etc). So, when compressed with H.264, such “static” nature of the video makes the file size 3-4 times less.

2.       The quality.
The agent screen recording is hardly the type of video you need to be of the highest quality. If you can read what agent typed when on phone – that’s enough. In our projects the quality setting of H.264 codec is usually 0,5-0,7.

3.       The FPS (frame per second) rate.

Most movies are shot at 24 FPS, but then again, this is not the case for screen recording in a contact center. You don’t need a smooth movie of the agent screen to understand what text is entered and which button is clicked. FPS 5-7 could be enough for recording the screen with CRM.