Glossary: Find a Definition

Key Performance Indicators

A performance indicator or key performance indicator (KPI) is a type of performance measurement. KPIs evaluate the success of an organization or of a particular activity in which it engages.

Key Performance Indicators (KPIs) are there to provide quick at a glance status of the performance of your infrastrcuture. They are found in two forms: either a snapshot or a trending value. They are also found in various place in the Dashboards and in the Reports. 

There are 3 main KPIs that Viakoo has invented to help Video Network Administrators do their jobs better. These are Video Path Uptime %, Video Stream Delivery Index %, and Video Retention Compliance %. There are KPIs for each of the levels, as they are based on different aggregate of streams for each level.

The logic goes as follows:

  • the Server level will have KPIs calculated based on the average of of all the Streams KPIs that make up that site. 
  • the Site level will have KPIs calculated based on the average of of all the Server KPIs that make up that site. 
  • the Company level will habe KPIs calculated based on the average of of all the Site KPIs that make up that company.


Proxy Server

A proxy server is server used in some networks to filter Internet usage and restrict access to unapproved websites and content.
It acts as an inspection station for Internet traffic to minimize the chance of inadvertently downloading malicious software.
It also can be used to restrict access to any website or group of websites that may contain unapproved content.
Most proxy servers require authentication by the use of a username and password.


A region is essentially a way to organize your company into different clusters of sites. For instance, instead of treating all of your sites to show up right under the company domain domain, you can organize the sites into geographical regions for organizational structures and performance purposes. Region a recursive in nature, which means you can have as many regions as you want underneath the company. 


In Viakoo, the concept of a streams is fundamental to understanding how the service works. 

A stream is continuous data in the form of packets originating from the lenses of a camera devices, all the way to a hard drive where is it being recorded. That stream passes through the infrastrcuture in various forms. The streams is ultimately readable by a human in the form of images. 



camera streams can tolerate small amounts of packet loss. But if packet loss reaches a critical threshold, the TCP connection to the camera will be reset causing a total loss of service to the camera for sometime 4 or 5 seconds.



Camera streams are live unique data streams that need to be delivered without any delay or packet loss.  Camera data is live and if a packet is lost it cannot be re-transmitted. If the packet is dropped it is lost forever.



In Greek language, the work 'Akou' is a gree verb meaning "to listen to the point of comprehension or understanding". It also happend to be the same root verb as the English work 'acoustic'. 

In the Italian language, the word 'Via' is the a preposition meaning "by way of; by means of; path". 

When you combine the two word and meaning, you end up with 'Viakoo' which means "the path to listening to the point of comprehension"


Video Network

A video network is a collection of systems that forms the video surveillance infrastructure. The video network is an amalgation of all the software and hardware components that allow the streamt be created, transported, and ultimately recorded. 

The video network has 3 main components. All of these systems for the video network. 

  1. the camera network, which is composed of camera devices, switches, and the network that allows communication
  2. the recorder(s), which can contain everything from the recorders hosting the applications, the workstations, and management servers
  3. the storage layer, which can be of various types such as DAS, NAS, SAN


Video Path Uptime

VPU measures the end-to-end stream availability from camera to storage media. Its goal is make sure camera streams are recording as designed. It is based on the aliveness of all components in the system, any component failures in the video stream path will cause VPU to degrade. The unit is percentage.


Given Recording schedule, when videos are recording properly, VPU = 100%, and videos are not recording due to failures, VPU = 0%. The failures can be any one of the following:

  • Any devices in video path failure
  • Cameras is not alive
  • No network sessions between VMS and camera
  • Storage media is not available
  • VMS recording service is not running

The site VPU = (sum of all camera VPU) / (Number of cameras in site)

The statistics collected further analyze what contributes most to VPU. Out of all the videos not recorded, how much is due to server outage? How much is due to camera outage? How much is due to network outage? How much is due to storage outage? How much is due to VMS outage?


Video Retention Compliance

VRC stands for Video Retention Compliance. This Key Performance Indicator (KPI) is a term invented by Viakoo to provide a quick at-a-glance status of your retention accross your streams. You will find a VRC% value aggregated at the Server, Site, and Company levels throughout the interface. 

The way this value is calculated is a currently patent pending. Our algorithms basically look at values inputed in various places in the infrastructure, notably your Video Management Software (VMS), to calculate your actual versus your desired retention and ensure you are meeting your goals. 

If one or more streams falls out of compliance, eg your are retaining less than the desired 30 days on a stream, the VRC% will drop. 

Video retention period is a compliance measure as it is required by the law in some situations. How long the videos have to be stored? Many times as many cameras are sharing the same storage device, and some cameras may have much higher resource utilization than others, which may cause retention imbalance. Monitoring storage utilization per camera is critical to achieve this. The unit is percentage as defined as the measured retention period over the desired retention period per camera. The site VRC is the average of all camera VRCs.

The video retention per camera is obtained through integration with VMS. In cases VMS does not provide direct information, the video retention period per camera is obtained by looking at file system timestamp, and video resource usage per camera is by file size usage.


Video Stream Delivery Index

VSDI% measures impact of video quality due to system components resource limitations. This is referred to as video gaps due to system performance reason. It is how many video gaps observed in the measurement cycle. The unit is in percentage.

VSDI% means that nothing is dead, but compoenant is leaking (frames). This is a measure of the quality of the stream. Whenever video gaps are identified, performance metrics from all components are analyzed. This will allow the end users quickly figure out the root cause of video gaps. Out of all video gaps, how many are due to storage? How many due to server processing? How much due to networking limitations?

A drop in VSDI% is usually an indicator of a strain on resources, for example:

  • network latency
  • dropped frames
  • storage latency
  • CPU above threshold
  • Bandwisth used 

VSDI% is different than VPU% Percent in the sense that a drop in VPU% means soemthing has already broken somewhere in the path and you are not recording video forone or more streams. A drop in VSDI% doesn't ncessarily mean missing video. 

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