Here at Comtrol, we rarely hear of customers who utilize networks that are configured in a ring. A star topology is almost always the way networks are configured by most of our customers across industrial automation, security, energy and other major markets we specialize in.
Likely one of the biggest reasons why people avoid a ring topology is that there is rarely interoperability between different brands of switches within that ring. There is also the fear of broadcast storm. If one switch goes down in a ring, you will have to buy that brand of switch again for use in that ring unless you remove all current switches and install another brand completely.
However, it’s worth mentioning that creating a ring network as a surveillance integrator can provide you with some real benefits that should be considered. In a nutshell, you will find that by using managed RocketLinx® switches in a ring, they will provide you with redundancy, quick recovery (less than 5ms), increased bandwidth, and even broadcast storm protection.
Redundancy: As depicted in the star topology diagram, there is not a whole lot of redundancy in that network. While a ring network holds the potential for a lot of redundant paths for the data to travel in should a single connection go down.
Quick Recovery: When configured in a ring, the managed RocketLinx Ethernet switches can actually repair this ring in less than 5ms. Whereas if someone is using rapid spanning tree in a star configuration, the time to reestablish itself (reroute the IP traffic through another path) in a tree can be anywhere between 5-30 seconds, and can certainly be noticeable if you are streaming live video.
Increased bandwidth: Another neat feature that the managed RocketLinx switches possess are their ability to do port trunking. Now this isn’t something that can only be used in a ring, but it certainly adds to the power of a ring. What port trunking will allow you to do is essentially double your bandwidth in a network between two switches. You can run two Ethernet cables between the switches and stream 2x the data from one switch to the other via this feature. In a ring as in the network example we provided above, trunking is being used between the floors. Not only are those switches capable of streaming 2x the data, but should one of the cables go down, you can still maintain at least one connection to get the data through (although your network will be slower).
This article, for the sake of brevity, is only scratching the surface with each of these topics regarding a ring topology. Comtrol is happy to talk in greater detail with each of its customers about the potential benefits of using a ring in their surveillance network. Also we know that there is an almost endless selection of Ethernet switches to choose from on the market, so we are happy to work with prospects and customers like you to get you the product to eval and test prior to your projects. We want you to experience firsthand the ease and reliability of our products prior to any large deployment.
For more information, please contact a member of our sales team at firstname.lastname@example.org or 800.926.6876