There are two key words when working with Skype for Business server 2015 that you should be aware of and those are: Active and Concurrent. These particular words will come up quite a bit when you are working with design, capacity planning, or troubleshooting an issue. At the end of the day, regardless of the scenario you are working with, its important to understand what these words mean and how to use them accordingly.
What is considered Active?
Active can be considered as what is happening at an exact moment in time; such as “How many active Peer-to-Peer or Skype to PSTN calls are taking place right now?” In this instance, this would mean that calls are actually taking place at that exact moment. Another scenario is “How many active users of Enterprise voice are enabled for your environment?” This might be confusing because depending on what sort of results the person who is asking the question is looking for the question could be interpreted in a few ways.
The last question could be interpreted as the following:
- How many people are enabled for Enterprise voice?
- How many people are actively using Enterprise voice in the environment?
This leads to the usage report example below.
Figure 1: Usage Report
This report shows how many people performed an action of one of the key modalities who made an IM, Conference, or Call. There is a difference between being logged on and not doing anything versus logged in and performing an action. You could say that it depends on the question that is being asked again.
Figure 1 displays the following information:
Total Logons– Total logons (rather, the users did anything or not once logged in) internal and external to the environment. This could mean that a user signed in and out ten times that single day and it would be counted in the total logon value.
Internal Logons– Users who signed in on the internal network or through a VPN connection. Unfortunately a single user can sign in multiple times and it counts in this value.
External Logons – Users who signed in from a remote connection (not VPN or internal network). Unfortunately a single user can sign in multiple times and it counts in this value.
Unique logon users– Pertains to unique individual people that logged into the environment. They don’thave to necessarily do anything once logged in.
Unique active users– Pertains to unique individual people that logged into the environment and performed an action stated above such as IM, Conference, or Call.
What is considered Concurrent? Here is an example of something that I run into all the time when working through the design of the Front End servers and Edge servers. Concurrent usage relates to the number of users that will be performing a task or service for the particular role at the same time. The edge server can handle up to 15,000 remote SIP connections concurrently. This mean that 15,000 users can be remote and the max supported connections for SIP that can be handled is 15,000 concurrent connections per Edge server. In my opinion that is a lot of connections.
Then, add to the equation that most deployments today consist of two edge servers for resiliency. So that means that the edge pool (if it consist of two edge servers) can handle 30,000 concurrent SIP connections. By definition, these numbers assume that the 15,000 connections have the capability to perform an action. So, in reality they are not talking about 15,000 connections that are just sitting idle, but rather assuming that those 15,000 connections are idle and ready to perform an action at any time. These are considered an active SIP connection.
Understand the Question
To be successful, you need to understand the question that is being asked and in what context the person is asking it. If all else fells you can use this article as a baseline to assist others with understanding the difference between Active and Concurrent.