有许多不同的方法来构建计算机网络(computer network)。网状(Mesh)网络拓扑正在慢慢成为家庭网络的新黄金标准，但拥有“网状拓扑”意味着什么？
我们将解释您需要了解的有关网络拓扑的最重要的事情，为什么网状技术是独一无二的，以及为什么它变得如此流行。
“拓扑”是什么意思？
拓扑是指事物彼此之间的排列方式。例如，一个区域的拓扑图很少用于详细导航，但它显示了兴趣点的“大图”排列。
在计算机科学和网络的背景下，拓扑是指网络元素如何链接在一起。它描述了网络上的哪些节点可以在通过另一个节点之前直接通信。
其他类型的网络拓扑
有五种一般类型的网络拓扑，每一种都有其优点和缺点。
线性总线拓扑(Linear Bus Topology )网络的所有节点都连接到单根电缆。这种电缆被称为“主干”连接，在该主电缆的每一端都有一个“终结器”。数据(Data)一次仅沿一个方向流动，称为“半双工”系统。
这是一个简单的网络设置，不需要太多布线。然而，总线拓扑的弱点是，如果主干电缆出现任何问题，整个网络就会停止运行。也很难确定网络上的哪个设备可能会导致问题，从而使故障排除非常耗时。
环形拓扑(Ring Topology )网络没有一根电缆，每一端都带有终结器。相反，所有节点都排列成一个圆圈，每个节点的两侧总是有另一个节点。与线性总线拓扑网络不同，环形拓扑网络以全双工模式运行，因此可以同时发送和接收数据。与总线拓扑一样，电缆中的任何故障都会导致整个网络瘫痪。
星型拓扑(Star Topology )网络是当今最常见的家庭网络类型。在这里，网络中的所有节点都直接连接到中央设备。这可以是网络交换机、集线器或路由器。所有网络流量都流经此主设备。
这种拓扑结构的一个缺点是网络拥塞的可能性，当然，集线器设备也可能成为单点故障。它还需要比有线网络中的上述网络拓扑更多的布线。
但是，在大多数家庭网络中，这不是问题，因为大多数设备都使用Wi-Fi连接到无线路由器，而以太网(Ethernet)则为少数设备保留。
树形拓扑（又名扩展星形拓扑，又名分层拓扑）(Tree Topology (aka Expanded Star Topology, aka Hierarchical Topology) )采用星形拓扑网络的概念并将其扩展为树状架构。例如，您的家庭路由器是星形拓扑的中心，但它是一个更大星上的节点，本地路由器是更大星上的一个节点。
不同的星型拓扑网络也连接到一根主干电缆，因此树型拓扑的“主干”是线性总线网络，“分支”是星型拓扑网络。
在我们解压缩网状拓扑时，请牢记这些通用网络设计。
网状拓扑
网状拓扑(Mesh Topology)网络提供任意两个节点之间的直接连接。与总线或环形拓扑不同，网络流量不必通过网络上的每个节点才能到达目的地。网络流量也不必像星型拓扑那样通过中央集线器。任何两个节点都可以私下通信，网络上的任何其他人都没有机会窃听。
全网状(full mesh)网络确实如此，但有两种类型的网状网络拓扑，所以让我们简要地解开第一种。
全网状拓扑与部分网状拓扑(Full Mesh Topology Versus Partial Mesh Topology)
有两种类型的网状拓扑。在全网状(Full Mesh )网络中，网络上的每个(every)节点都与其他每个节点都有点对点连接。这意味着无论两个节点位于网络上的哪个位置，它们之间都存在直接的有线或无线连接。这需要最复杂的布线，每个节点添加的连接数量都很快。
Partial Mesh网络在其设计中具有相同的基本理念，即网络上的节点直接连接到其他节点，但并非每个节点都连接到其他每个节点。每个节点都至少连接到一个其他节点，并且通常不止一个，但部分网格并不那么复杂。
网状拓扑的优势
全网状网络的主要优点是冗余连接。即使任意数量的节点之间的直接连接失败，它们也总是可以通过路由通过另一个网络节点来通过，即使它没有那么快。更好的是，通过设计很容易确定故障所在，因此修复问题相对容易。
从这个意义上说，全网状网络就像整个互联网一样，其中至少有一条可行的数据传输路径始终可用，即使大型网段出现故障。部分网状网络提供较少的冗余，尽管网络设计人员可以专注于为最关键的节点提供最多的连接，平衡冗余、成本和复杂性。
除了冗余之外，网状网络在网络性能方面具有显着优势，因为节点都可以同时发送和接收数据，从而选择最有效的网络路由。这意味着可靠、低延迟的网络性能非常适合智能家居中的(Things)IoT（物联网(Internet)）设置。
(Mesh)由于数据在全网状系统中的网络设备之间移动，因此网状网络具有出色的隐私性。
最后，网状网络具有出色的可扩展性，不会对网络性能或带宽产生负面影响。通过添加新节点并将它们连接到最近的节点（部分网格）或所有其他注释（全网格），网状网络可以随着时间的推移有机地增长。
网状拓扑的缺点
网状拓扑的两个主要缺点是成本和复杂性。部分网状设置有助于平衡这些问题，但全网状有线网络就像蜘蛛网一样。
网状(Mesh)网络比其他网络类型具有更高的功耗。这是因为所有节点都必须处于活动状态并打开才能为数据提供路由路径。由于必须修复或更换因任何原因出现问题的单个节点以维持网络性能，因此维护负担也很重。
家庭无线网状网络
家庭中使用的局域网( LAN(LANs) ) 传统上是星形拓扑网络。(Area Networks)所有设备都连接到中央路由器，无论是通过Wi-Fi还是以太网(Ethernet)。随着智能设备和家用电器的兴起，整个家庭对互联网连接的需求也在增长。
如果不使用中继器或扩展器，(repeaters or extenders)集中式设备可能会导致性能瓶颈并限制有线连接和无线信号的覆盖范围。中继器和扩展器具有复杂的配置和较差的网络性能，因此它们不是整个家庭网络的理想解决方案。
家庭中的网状(Mesh)网络路由器是部分网状网络的一个示例，或者可能是一种混合拓扑。并非所有节点都连接到每个节点。相反，主节点连接到WAN（广域网(Wide Area Network)），这是指家庭网络之外的更大互联网的另一种方式。
该主节点直接连接到笔记本电脑和智能手机等设备，但它也建立了与其他网状网络单元的专用无线连接。每个(Every)网状路由器都以最佳的连接速度和可靠性连接到以下网状单元。这种连接可以通过 Wi-Fi 或以太网“(Ethernet “)回程”，其中高速电缆连接一些网状路由器单元。
当设备在家中移动时，它们会在网状单元之间无缝切换，因为每个单元都会中继到互联网的路径。智能手机等客户端(Client)节点不用作网格的一部分。没有流量通过一个客户端设备直接路由到另一个客户端设备。所有流量都传递到最近的网状路由器节点。如果您想扩展网络以提高性能或覆盖范围，请添加更多网状单元。
如您所见，家庭使用的“网状”无线网络与实际网状网络的模板不太匹配。相反，它更像是通过一组专用网状子连接将多个星形拓扑网络连接在一起。
尽管如此，这仍然是最先进和无缝的家庭网络解决方案(seamless home network solution)。我们可以向任何人推荐一个，假设您的预算将延伸到这项新技术。
What Is Mesh Network Topology?
There аre many different ways to build a computer network. Mesh network topology is slowly becoming the new gold standard for home networks, but what does it mean to have a “mesh topology”?
We’ll explain the most important things you need to know about network topology, why mesh technology is unique, and why it’s becoming so popular.
What Does “Topology” Mean?
Topology refers to how things are arranged in relation to each other. For example, an area’s topological map isn’t used much for detailed navigation, but it shows the “big picture” arrangement of points of interest.
In the context of computer science and networks, topology refers to how the elements of a network are linked together. It describes which nodes on a network can communicate directly before going through another node.
Other Types of Network Topology
There are five general types of network topology, each with its advantages and disadvantages.
Linear Bus Topology networks have all nodes connected to a single cable. This cable is known as a “backbone” connection, with a “terminator” at each end of this main cable. Data only flows in one direction at a time, known as a “half-duplex” system.
This is a simple network setup that doesn’t require much cabling. However, the weakness in a bus topology is that the entire network stops functioning if anything goes wrong with the backbone cable. It’s also hard to pinpoint which device on the network might be causing issues, making troubleshooting time-consuming.
Ring Topology networks don’t have a single cable with terminators on each end. Instead, all the nodes are arranged in a circle, with every node always having another node on both sides. Unlike linear bus topology networks, ring topology networks operate in a full-duplex mode so that data can be sent and received simultaneously. Like bus topology, any fault in the cable brings the whole network down.
Star Topology networks are the most common type of home network today. Here, all of the nodes in the network have a direct connection to a central device. This can be a network switch, hub, or router. All network traffic flows through this primary device.
One disadvantage of this topology is the potential for network congestion and, of course, the hub device as a single point of failure. It also requires much more cabling than the above network topologies in a wired network.
However, in most home networks, this is a non-issue since most devices are connected to the wireless router using Wi-Fi, with Ethernet reserved for a handful of devices.
Tree Topology (aka Expanded Star Topology, aka Hierarchical Topology) takes the idea of a star topology network and expands it into a tree-like architecture. For example, your home router is the center of your star topology, but it’s a node on a bigger star with a local router, which is a node on an even bigger star.
The different star topology networks are also connected to a backbone cable, so the “trunk” of the tree topology is a linear bus network, and the “branches” are star topology networks.
Keep these general network designs in mind as we unpack mesh topology.
Mesh Topology
A Mesh Topology network offers a direct connection between any two nodes. Unlike bus or ring topologies, network traffic doesn’t have to pass through every node on the network to reach its destination. Nor does network traffic have to pass through a central hub as it does with a star topology. Any two nodes can communicate privately, with no chance that anyone else on the network can eavesdrop.
That’s true of full mesh networks, but there are two types of mesh network topology, so let’s briefly unpack the first.
Full Mesh Topology Versus Partial Mesh Topology
There are two types of mesh topology. In Full Mesh networks, every node on the network has a point-to-point connection to every other node. This means that no matter where two nodes are located on the network, there’s a direct wired or wireless connection between them. This requires the most complex wiring with the number of connections rapidly with every node added.
A Partial Mesh network has the same basic philosophy in its design that nodes on the network connect directly to other nodes, but not every node is connected to every other node. Every node is connected to at least one other node, and often more than one, but the partial mesh isn’t nearly as complex.
The Advantages of Mesh Topology
The main advantage of a full mesh network is redundant connections. Even if a direct connection between any number of nodes fails, they can always get through by routing through another network node, even if it isn’t as fast. Even better, it’s easy to pinpoint where the fault is by design, so fixing things is relatively easy.
In that sense, full mesh networks are like the internet as a whole, where at least one viable route for data transmission is always available, even if large network segments go down. Partial mesh networks offer less redundancy, although the network designers can concentrate on giving the most critical nodes the most connections, balancing redundancy, cost, and complexity.
Besides being redundant, mesh networks have a significant advantage regarding network performance since nodes can all send and receive data simultaneously, choosing the most efficient routes through the network. This means reliable, low latency networking performance perfect for IoT (Internet of Things) setups in smart homes.
Mesh networks have exceptional privacy since data moves between network devices in full mesh systems.
Finally, mesh networks have excellent scalability without negatively affecting network performance or bandwidth. A mesh network can grow organically over time by adding new nodes and hooking them into the nearest nodes (partial mesh) or all other notes (full mesh).
The Disadvantages of Mesh Topology
The two main disadvantages of mesh topology are cost and complexity. Partial mesh setups help balance these issues, but a full-mesh, wired network is like a spider’s web of connections.
Mesh networks have higher power consumption than other network types. That’s because all nodes must be active and turned on to provide routing paths for data. There’s also a significant maintenance burden since individual nodes that develop issues for any reason must be fixed or replaced to maintain network performance.
Wireless Mesh Networks in the Home
Local Area Networks (LANs) used in the home have traditionally been star topology networks. All devices connect to a central router, whether by Wi-Fi or Ethernet. The need for internet connectivity in the entire home is growing with the rise of smart devices and home appliances.
A centralized device can cause performance bottlenecks and limit the reach of both wired connections and wireless signals without using repeaters or extenders. Repeaters and extenders come with complex configurations and worse network performance, so they aren’t the ideal solution for whole-home networking.
Mesh network routers in the home are an example of partial mesh networks or perhaps a type of hybrid topology. Not all nodes are connected to every node. Instead, the primary node connects to the WAN (Wide Area Network), which is another way of referring to the greater internet beyond your home network.
That primary node is connected directly to devices like laptops and smartphones, but it also sets up dedicated wireless connections to other mesh network units. Every mesh router connects to the following mesh unit with the best connection speed and reliability. That connection can be over Wi-Fi or through Ethernet “backhaul,” where a high-speed cable connects some mesh router units.
As devices move around the home, they are seamlessly handed off between mesh units as each one relays the path to the internet. Client nodes such as smartphones are not used as part of the mesh. No traffic is routed through one client device directly to another. All traffic passes to the nearest mesh router node. If you want to expand the network to improve performance or coverage, add more mesh units.
As you can see, “mesh” wireless networks for home use don’t quite match the template of an actual mesh network. Instead, it’s more like having several star-topology networks linked together by a set of dedicated mesh sub-connections.
Still, this is the most advanced and seamless home network solution. One we can recommend to anyone, assuming your budget will stretch to this new technology.
