Due to what the throughput drops when switching packets?

Question

network hardware

However, the overall throughput with packet switching will be higher than with circuit switching techniques. This is because the ripples of individual subscribers, in accordance with the law of large numbers, are distributed in time so that their peaks do not coincide.

I don't quite understand the phrase in bold.

I understand that throughput can decrease when data from multiple devices arrive at the same device. For example, data from C, D and K are sent in parallel to subscriber B. And it turns out that the peaks of the paths CB, DB, KB may not coincide in time (if we talk about packet switching). Do I understand correctly?

Or does throughput always decrease when shared switches are used? As in the diagram above, path 1-7 and path 4-8 share a common switch. I don't quite understand how it all happens.

Answer 1

If we talk about the quote at the beginning of the question, then the bandwidth of the network of voice subscriber traffic with packet switching is higher than that of circuit-switched networks, with equal physical bandwidth of the equipment that forms the transmission medium, because the silence of the subscriber is not transmitted in the channel, even if it is open, in a packet-switched network. At the moment of silence or a decrease in the load on the voice channel, the volume of the payload of the subscriber's traffic decreases and the channel is occupied by a smaller number of packets. In a circuit-switched system, the channel is open - always open, always busy, even if it drives silence

Answer 2

A simple analogy: a railroad network (circuit switching) and a highway network (packet switching). In general, it is easier to get from point A to point B by car ...

Answer 3

As far as I understand it, it is not always correct to do 10 hops on the main 10g backbone, if 3 hops are enough for 1g, but rstp can calculate otherwise the channel weight

Answer 4

Apparently, we are talking about oversubscription or traffic multiplexing. The aggregate bandwidth of services on a packet network can miss the bandwidth of the network itself, since the traffic of each individual subscriber does not take up all the bandwidth at all times.
But this is not always applicable in practice. For broadband operators, good oversubscription works at the level of Access, and Access rings. Conventionally, 24 apartments can be switched on 100 Mbps - 1 Gbps on the access switch, but the average consumption in the CNN is no more than 20 Mbps. In the access ring (4-8 switches), the consumption will be no more than 80 - 160 Mbps. Etc.
For opposition - DWDM. Regardless of the presence of useful traffic, DWDM completely occupies the resources of a dedicated channel.