Network technology - switches and cabling

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Switches and cabling play a central role in network technology. The differences and selection criteria to be considered are discussed below.

Network cable

shielding

Network cables are designed as 4-pair twisted single cables with a common copper braid to shield external interference fields (S/FTP - Screened Foiled Twisted Pair). The twisting eliminates internally occurring interference fields.
Cables with individual wire pairs additionally shielded with braiding are referred to as S/STP cables (Screened Shielded Twisted Pair).
For FTP cables (Foiled Twisted Pair), an aluminum-coated foil is used instead of a copper braid.
A so-called drain wire serves as a ground wire in all variants.

UTP cables (Unshielded Twisted Pair), which do not have any shielding and therefore do not have a two-wire connection.

Classification (CAT)

The categories CAT1 to CAT6(A) are not covered, as they no longer meet today's bandwidth requirements if 10 Gbit/s Ethernet or higher is required.

From CAT7, the wire pairs are individually shielded. They meet the requirements of IEEE 802.3ancan be used up to 600 MHz, CAT7A up to 1,000 MHz and data rates of up to 10 Gbit/s in 10GBASE-T applications.
The maximum cable length is 100 m at the nominal transmission speed.

The highest data rate is currently achieved by CAT8.2 category cables, which have a bandwidth of 2 Gbit/s and a data rate of 40 Gbit/s for 25 GBASE-T and 40 GBASE-T applications.
With 40GBASE-T, the cable length is limited to 30m.

Fiber optics vs. copper

The performance of copper cables, especially CAT8, is now comparable to fiber optics. Nevertheless, there is a difference that can only be realized with copper, namely PoE (Power over Ethernet), the power supply for consumers such as cameras via the Ethernet cable.

If PoE is not required, the trend is towards fiber optics, although the handling, such as the assembly of the plug connections, is far more complex and special tools are required.

Price question

The price difference between CAT7(A) and CAT8(.1/.2) is marginal with 10%. You can calculate around 10 euros for 3m CAT7 and around 11 euros for CAT8.1.
However, it is important to remember that the infrastructure, such as switches, must also meet the classification requirements if they are not to be the bottleneck in the data flow.

Hub vs. switch

Hubs and switches are used to distribute the incoming data stream, e.g. from the router, via available port connections to end devices such as computers, printers, scanners, cameras or other network devices.

Stroke

The hub distributes the incoming data stream evenly across all ports. Connected subscribers receive the data stream.

Switch

A switch analyzes the header of the received data stream. The recognized MAC address defines the target device. If the MAC address is not recognized, it sends the data packet to all ports. As soon as the relevant target device responds, it transmits its MAC address, which the switch then enters into its CAM (Content Adressable Memory), also SAT table (Source-Adress-Table) is entered. This means that packets can be forwarded immediately to the correct destination address using the MAC address.
The direct assignment via MAC address avoids collisions of data packets and enables full-duplex communication, which optimizes data throughput.

Switches can also create virtual LANs (VLAN) and distribute data traffic to different logical networks and thus process them separately from each other.

ports

The number of ports is variable, from 4, 8, 16, 24 up to 48 ports, everything is available on the market.

You should therefore first make a note of all devices that are to be connected to a switch via LAN.

For end devices to be supplied via PoE, the power consumption must be taken into account. This is because the sum of all PoE ports determines the required total power of the switch's power supply - and therefore also the price.

A 16-port switch, for example, may provide 12 non-PoE ports and 4 PoE ports. It is therefore important to check how many PoE ports are actually available - and with what power.

In view of the usually growing network infrastructure, a certain reserve in the number of ports and PoE ports should be considered.

Switches - (un)managed

Many manufacturers share the market. From my point of view, it is always advisable to choose a manufacturer that is active in the business sector and therefore has sound experience in this market segment.

A distinction must be made between so-called managed and unmanaged Switches. Only managed Switches are configurable. Even if configurability is rarely important for the individual user at the beginning, as is usually the case in life, the demand increases over time and the need for a configuration option becomes foreseeable.

The simplicity of the configuration decreases with increasing professionalism and the associated increase in administrative complexity.

However, a switch always "works" in its basic factory configuration. This means that - for the time being - no configuration effort is required, albeit optional.

In this respect, you can now rely on managed switches.

Manufacturer of switches

In my opinion, the agony of choice is reduced to two manufacturers. Anyone with an affinity for Cisco will choose Cisco without question. Anyone who is not yet biased, does not have an endless budget at their disposal and is not a business professional when it comes to networking will learn to appreciate Ubiquiti.

What both manufacturers have in common is that, as a rule, larger switches (in some cases from 8 or 16 ports) provide uplink ports (SFP/SFP+ with 16 Gbit/s or Enhanced Quad-Small Form-factor Pluggable with 40 Gbit/s (QSFP+)) by means of fiber optic connections, usually 2 or 4.
QSFP-DD (Double Density) supports up to 56 GBit/s and 400 Gbit/s.

The maximum cable length for uplink ports according to the above standards is 550 m (multimode) or 10 km (singlemode LX), or 40 km (singlemode EX) and 80 km (singlemode ZX), depending on the fiber type.

CWDM and DWDM modules even enable distances of up to 80 or 120 km, provided that the corresponding transmission power and reception sensitivity are available.

Cisco

The most renowned manufacturer is probably Cisco. Non-professional users are often put off by the administration, which covers almost all possibilities and is therefore very complex. In the professional environment, Cisco is indispensable and a quasi-standard.

SG and CBS (Cisco Business Switch) serve private users such as small to medium-sized businesses, Cisco Catalyst is aimed at industrial users and Cisco Nexus at network structures that require high scalability and corresponding performance.

Ubiquity

Ubiquiti is a manufacturer originally active in the professional sector, not only of switches but also WLAN and radio relay components, which offers a consumer range with professional technology from the business sector at affordable prices.
It is also characterized by 24/7 online RealTime support, which can be called up from the controller GUI and can also be connected remotely. Session logs are recorded and made available by email at the end of the session. This means that the steps can still be traced in detail afterwards.

UniFi and Edge are the divisions offered by Ubiquiti for the consumer and enterprise market. Both lines have the advantage of comprehensive, network-wide visualization and central, dedicated management via UniFi CloudKey Controller or UniFi DreamMachine (UDM), especially in conjunction with the UniFi Camera System (UniFi Protect) or UniFi DreamRouter (UDR).
All Pro or Enterprise variants support extended Layer 3 functions, such as VLAN.