Along with VLANs, QoS is one of the most misunderstood topics in IP surveillance networks. Many purported "experts" claim it is required in any and all surveillance systems, but little clear guidance is given about why, leaving those new to the field confused. In this note, we cover the basics of QoS, what it is, how it is applied, and when it should be used.
Inside we explain:
What is Quality of Service
How Quality of Service is Applied
Limitations
Practical Uses
Setting up QoS
Quiz Yourself: 5 Question Quiz to measure your knowledge on QoS for Surveillance
Thanks for the great article :) Would love to see more on managed switch settings for video optimization and security. Personally I don't think that I use a managed switch to its full capacity.
Extra security always a good idea. But if you don't have any video quality issues then I would say let it be unmanaged. And you will never use a truly managed switch to its full capacity capabilities because many of the settings are for special situations and sometimes old technology. I see more problems with customers that decide to tinker around in the settings doing more harm than good. Not saying you would be one. But I know I have locked myself out of my share of switches/routers.
You may already be aware of this, but one beneficial thing your managed switch should be able to do that comes in handy is turning POE on and off for each port. Network admins lazy cure all. Boot it.
Given most integrators prefer to run their surveillance systems on a dedicated network, QoS is generally not needed.
Yes but even with all the cameras on a dedicated network, the viewing clients are typically on the corporate LAN. Moreover, this bandwidth demand is not bound to the number of camera streams, but to the number of viewers of those streams.
Wouldn’t QoS possibly be helpful when deployed on those segments?
Given most integrators prefer to run their surveillance systems on a dedicated network, QoS is generally not needed.
QoS could still be important on a private LAN if you consider that you may have cameras that are more critical than others and possibly have choke points with uplinks in your network.
Wouldn’t QoS possibly be helpful when deployed on those segments?
This would depend on the capabilities of the camera, are you multicasting? Then no, but if you set up multicast into the customer's environment will you melt their core? Maybe. Without the correct forever morphing network design (or you can use the right core equipment and then yes, multicast is easy), this might not be the route you want to go. If you do, call us.
If you are doing two unicast streams from the camera (if capable), then you are using twice the bandwidth (assuming same quality, frames, etc.). QoS will be helpful if you have cameras more important that others.
However if you are pulling from the VMS, then you can design it such that this should not be an issue.
I was trying to answer the question completely. I will try a general answer though, gotchas included:
If you have a lot of camera data and certain cameras matter or on the customer's network camera data means more that other traffic (like general internet) then yes, QoS can benefit if there is a constriction in the network.
My 1st answer was trying to address the challenges in the dedicated network, the uplinks to the customer network and possibly video needed across a WAN link. QoS can address priority or address reserved bandwidth, usually not both.
QoS of some type is beneficial to any size network. Even a single computer. Especially a windows PC. Usually one PC on an Internet connected network has sufficient amount of bandwidth. But lets just say they only have a 5 mbps up and down Internet connection. And user leaves Window updates to default settings. When patch tuesday rolls around the corner while the user is online gaming, there will be issues. Microsoft will open about 30 download and 30 upload connections at once. Which stomps the quality right out of your service.
Microsoft will open about 30 download and 30 upload connections at once. Which stomps the quality right out of your service.
With or without the gamer online, it sounds like the Internet for the office is going to be impacted. So how would you configure the QoS in such a situation containing surv video as well?
However, this is generally not used, as it is featured in more expensive enterprise switches, and restricted to trunk connections between switches or WAN connections.
You're doing great job posting those network-related articles!
regarding this one, I agree with a conclusion: most of the security networks are physically separated from the data networks, so QoS is not something people need to think about. And if we have a big corp network with different services, including CCTV, there's always a qualifier network admin to think about architecture so CCTV guy don't need to do anything, except setting up the numbers in the device settings
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Comments (15)
Randy Lines
Thanks for the great article :) Would love to see more on managed switch settings for video optimization and security. Personally I don't think that I use a managed switch to its full capacity.
rbl
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Undisclosed Manufacturer #1
Great article
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Undisclosed #2
Yes but even with all the cameras on a dedicated network, the viewing clients are typically on the corporate LAN. Moreover, this bandwidth demand is not bound to the number of camera streams, but to the number of viewers of those streams.
Wouldn’t QoS possibly be helpful when deployed on those segments?
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Walter Holm
.
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Chad Rohde
Generally not used maybe, but it is also featured in sub $20 SoHo wifi routers/switches/APs. No restrictions that you mention either.
I know my beloved Mikrotik will win this argument and require an edit to original post.
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Dennis Ruban
You're doing great job posting those network-related articles!
regarding this one, I agree with a conclusion: most of the security networks are physically separated from the data networks, so QoS is not something people need to think about. And if we have a big corp network with different services, including CCTV, there's always a qualifier network admin to think about architecture so CCTV guy don't need to do anything, except setting up the numbers in the device settings
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Jon French
Good info
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