In IP surveillance networks, quality of service is one of the most misunderstood concepts. Many so-called experts claim it’s essential in all surveillance systems, but little is made clear about why. As a result of the lack of information many individuals new to the industry are easily confused.
What To Know
To manage bandwidth for specific applications, Quality of Service (QoS) strategies are used. The standard applies to IP video and VoIP services that are typically integrated into a network where typical data traffic (file transfers, internet use, etc.) is present.
Due to their latency-sensitive nature, video and voice are highly affected by bandwidth management. This results in packet loss and high latency. As a result, frames may be dropped, streams may be degraded, cameras may disconnect, or other effects may occur.
QoS Applications
- Application: Perhaps the most common method of setting QoS is by application. By categorizing and allocating bandwidth according to the type of application, this method categorizes and allocates bandwidth. It may be necessary to assign a lower priority to FTP traffic in order to maintain better quality and frame rates. In order to set QoS according to an application, all components (cameras, switches, servers, etc.) must support QoS, normally via DiffServ, what is currently the most common way to tag traffic according to its usage.
- VLAN: Different VLANs can have different quality of service (QoS), allowing security VLANs to share bandwidth more heavily than office LANs. QoS is set at the switch, so no further changes are required at the end devices. However, all devices must support VLAN tagging in order to implement QoS by VLAN.
- User: It’s also possible for QoS to be set by the user, however, this technique is not typically used in security. There are still some network administrators and database workers that may prefer this method, as they require guaranteed bandwidth for their work, while those working on lighter tasks usually do not. However, in order for this method to work properly it is tied to network login and involves a more complicated QoS setup.
Regardless of the method used, managed switches are required if QoS is desired, since unmanaged switches cannot be configured for QoS.
No Bandwidth Guarantee
In most cases, QoS refers to prioritization rather than bandwidth guarantees, arranging the order in which packets / data are queued for transmission.
As opposed to a simple prioritization, some switches may allow bandwidth reservation, which limits the amount of bandwidth available to specific services. Due to its cost, this feature is only typically found in enterprise switches and is only used for trunk connections between switches. It is usually sufficient to prioritize via DiffServ.
Understanding Different Security Network Options
In IP video installations, which most commonly use a dedicated security network, QoS has a minimal effect. Using several systems on the same network, such as surveillance, access control, and IP intercom, may result in some benefits. However, overall it is unlikely to be beneficial.
The quality of service is vital to any system in a shared network. It is likely that available bandwidth without QoS will suffice in a small retail or office application that has four or eight cameras sharing a switch. However, there is a more pressing need for QoS in larger networks. Such as those within schools, mid-sized offices, campuses, etc., since these networks easily become overloaded.
If you are looking to update security features for your business, like the Quality of Service for your Video Surveillance let RC Security help. Our continued research and partnerships with premium brands allow us to offer better quality every time.
About RC Security Consulting
RC Security Consulting protects the heart of Texas with design, installation, retrofit, repair, inspection, and monitoring of commercial security systems. We are centrally located in Collin County and provide service for almost 200 miles in all directions. Connect with us on LinkedIn to learn more.
