Preparing a Microsoft Lync Environment › System Scalability

System Scalability

In our testing, we measured the size and volume of quality reports to derive some guidelines about bandwidth consumption for the Lync collector. When the Lync collectors send quality reports in batches to the web service on the management console, the bandwidth consumption is roughly as follows:

• Audio calls: 3500 bytes per report, or 7000 bytes per call
• Audio + video calls: 5300 bytes per report, or 10,600 bytes per call

The Microsoft capacity-planning guidelines identify 125 reports per second as the limit for a monitoring server. This represents call traffic from more than 125,000 users. With this benchmark, the bandwidth consumption is as follows:

• Audio calls: 125 reports per second multiplied by 3500 bytes per report = 437500 bytes per second = 3500 kbps = 3.5 Mbps.
• Audio + video calls: 125 reports per second multiplied by 5300 bytes per report = 662500 bytes per second = 5300 kbps = 5.3 Mbps

The baseline of 125 reports per second equates to a call volume of more than 220,000 calls per hour. A more likely enterprise benchmark that we observed in our testing is closer to 22,000 calls per hour:

• Audio calls: 12.5 reports per second multiplied by 3500 bytes per report = 43750 bytes per second = 350 kbps
• Audio + video calls: 12.5 reports per second multiplied by 5300 bytes per report = 66250 bytes per second = 530 kbps