Determining the placement and number of nodes needed
The number of nodes you require depends on five factors:
- The size of the area you need to cover.
- How many walls and floors you need to penetrate with mesh.
- The material of the walls and floors you need to penetrate.
- The amount of interference in your environment.
- The number of simultaneous users expected on the network.
In Datto Networking, you'll be able to see the speed of each device and signal strength between devices (both of which decrease over distance and through walls and floors). Look for a signal strength (or "RSSI") to be no higher than -65, where -30 to -50 is desirable. You can add, remove, or reposition nodes as needed at any time.
While we've tested more than 250 users on a single node in the lab, you should aim for no more than 20-50 users per node to give each user an optimal experience. The maximum number of users will vary based on your network environment, ISP connection, and bandwidth to each client device.
With any model, it is possible to overpower dense indoor networks. However, you can turn the transmit power down through Datto Networking if you experience symptoms such as interference or dropped connections. Setting TX Power to 19 or 21 dBm typically resolves these issues.
For large installs, test your environment with Datto and two or three nodes before buying all of the nodes. You'll be able to see the range and how many walls and floors you can expect to transmit through in your specific environment. Nodes transmit in a spherical pattern—up, down and side to side—so there's no need to “aim” signals.
Here are some guidelines to help plan how many nodes are needed for your installation.
Hotels and apartments:You will typically need one node for every four to six hotel rooms or apartments. This will vary depending upon the type of construction and layout. If you are in a single-story, single-row concrete/ brick/stone build, you may need one node in every second or third unit. For wood frame multistory buildings with interior hallways and small rooms, one node for every six or seven rooms may be sufficient if placed in a central hallway.
When installing multistory buildings, we recommend placing units on every second floor for both concrete and wood buildings. Copper ceilings, steel plating, cement and adobe-type materials may limit (and even eliminate) signal transmission between floors.
Coffee shops and restaurants: One well-placed node can usually cover an entire coffee shop. For restaurants or large coffee shops, you may need two or three nodes, especially if you want to cover outdoor seating areas.
Small and medium-sized businesses: One well-placed node can usually cover a small retail shop. For larger spaces, use the numbers in the table above to plan the number of access points based on the number of walls to penetrate.
Residential neighborhoods: In residential neighborhoods, we recommend that each house have at least one node. And if the houses are especially large, you can add multiple nodes to the house to provide better coverage in every room. Wherever possible, place nodes near windows or exterior walls with a direct line of sight to the nodes in other houses. Placing some nodes outside may help extend coverage more efficiently.
Determining a location for your gateway(s)
Gateway Users on mesh networks will lose half—or more—of their maximum speed for every hop they are away from a gateway. Therefore, you want to place the gateway(s) as central to the area you want to cover as possible. As you can see below, forcing traffic through too many hops quickly leads to very slow network speeds.
By moving the gateway from one end to the center, as shown below, you can improve the maximum potential speed on the outer reaches of the network by a multiple of four.
If most of your repeaters have a direct (or single “hop”) connection to the gateway, their speed is maximized. The easiest way to accomplish this, is to put your DSL/cable/fibre connection as close to the middle of the area you want to cover as possible.
Scaling your network
Datto networks are highly scalable. To build large-scale networks, simply repeat the model above as needed by adding additional gateways and repeaters. There is virtually no limit to the number of gateways and repeaters you can have on a single network (although we recommend 200 or fewer nodes for readability of reports). Larger networks can simply be broken up into discrete zones under the same login.
There are two primary ways to add additional gateways: you can have multiple DSL's (cable modems, etc.) or have a switch with Ethernet cables, both distributing gateways evenly through your network.
The advantage of multiple DSL's feeding your network is twofold. First, you avoid running any Ethernet cabling. Second, you have a built-in failover: if one DSL were to go down, your network will switch-over to the other DSL(s) keeping your network up, if a bit slower. However, there is typically a higher ongoing cost to providing multiple low-speed DSL's compared to one high-speed DSL. With a switch running Ethernet to multiple gateways, you have a one time investment but a reduced on-going cost because you are only paying for one DSL connection.
Here are some additional network planning suggestions:
Have the edges of the signals from nodes overlap so that each node can talk to at least one (and preferably two) other nodes, with good signal quality.
Don't under install. Having redundancy built into the network by having extra nodes allows Datto Networking's self-healing, self-configuring mesh protocol to keep users connected and minimize outages.
To avoid bottlenecks, don't have more than five repeaters running off of any one gateway.
Think vertically in multistory buildings. If you have two or three floors to cover, place the nodes on the second floor. This keeps them centered between the floors where they can provide coverage both above and below. You get all of the coverage with half of the nodes.
Use straight lines when broadcasting through walls and floors. The less material the wireless signal needs to penetrate, the stronger the signal will be.
If you are installing in an apartment complex or hotel with internal hallways and no in-room cat5/6 Ethernet cabling, consider placing most nodes in the hallways. As this is common space, you'll have access to them without disturbing residents. Secondly, placing the nodes down a long corridor means they can all see each other without having to go through as many walls. This maximizes the signal between the routers and minimizes potential “hops” and low signal quality that will slow down the network. Add additional nodes as needed (typically in larger units) to boost signals in specific areas.
If you are installing a building that has cat5/6 Ethernet cabling to each room, consider using the indoor Ethernet enclosure to add gateways to as many rooms as needed. In this scenario, you could do without repeaters completely, maximizing your network performance.