Funny, I was going to ask the same question.
I'm a rookie in video and recently discovered (the hard way) that some switches are geared towards VOIP. I guess they can be lacking in buffer size/throughput.
IndigoVision Ltd | IPVMU Certified | 12/08/14 11:41am
I am not an Specialist in Video dedicated switches but just wanted to share some feedback.
More and more Network Switch manufactures are developing switches that have some set of features dedicated to video. For example, multicast, larger buffers, less delay, etc...
Cisco has some they sell a lot for cable companies, etc...
If i'm not mistaken they recomend Cisco Catalyst 3560-X and higher for video.
I don't know if they would recomend a specific set of switches for CFTV, i imagine it would be the same for youtube video and cable video which needs slow delay.
Anyways, VOIP is easy to handle, altought you have a lot of QoS features out there, if you have a packet loss of about 60% you can still understand the voice transmission.
Regarding Video, if you lose a single frame you might have already lost the most important image of the whole transmission.
Here's the deal. Packet loss is a fact of life in IP networks. It's just a matter of how much you're going to experience given the environment of cable plant, network infrastructure and attached devices.
The only rule of thumb is, unfortunately, "you get what you pay for." Higher end switches from reputable companies are (probably) going to honor their specs better than an el-cheapo switch. Managed switches are going to provide more features, control and visibility into what's happening on the network as well.
Protocols based on TCP are designed to accomodate this with retries of lost packets. So if you're dealing with TCP vs UDP there are implications of that. Video can be tricky due to the fact that a lost packet with UDP can make the video look pretty bad.
Little anecdote: we were seeing higher packet loss on a little Netgear 8/16 port POE switch vs. on a Cisco 8/16 port switch. Both roughly in the same price range. This was combined with our own networking software that wasn't gracefully handling the packet loss. Problem would (mostly) go away with the Cisco switch vs the Netgear switch. The real solution was to fix our software, which works fine now on both switches. But just goes to show that you can experience a different level of performance from two switches that otherwise work just fine for day-to-day network uses. BTW, when we wanted to OEM a switch we looked for a vendor who could supply us with similar hardware architecture to the Cisco switch as some added insurance..
My advice is to learn how to recognize and measure packet loss then try gear for yourself. Keep track of where and under what conditions you're seeing more packet loss and try to minimize it with known good equipment and your own best practices. Listen to recommendations from others who are successful but try it for yourself too. IP video is network-intensive, and tends to present slightly different use cases than most networking environments are designed for. You provide the most value to your customers if you understand this stuff yourself.