How to calculate PPS (packets per second) based on the estimated number of users?

Question

Computer networks

Good afternoon, I ask for help, there is a task - to put network equipment between the provider and the client. The client has an operating network infrastructure designed for 3000 simultaneously connected devices (smartphones, laptops). It is planned to allocate 0.5 -1.0 Mbps for each device. Based on this, I can calculate the approximate bandwidth required only for traffic, but I also need to take into account the interaction between network equipment and user devices. Hence the question - how can you calculate the required performance of a router / switch
in PPS in order to select the optimal model? I haven’t faced a similar task before and I can’t imagine how it can be calculated correctly, it’s impossible to predict what users will do, someone will receive mail, someone will watch video in 4k ...
Due to existing agreements, you need to choose a router / switch or a stack of Mikrotik equipment that can digest it all and not melt. The less iron required, the better.

Answer 1

Since there is already an existing infrastructure - shoot traffic and analyze + make a reserve of 20-30%.
In general, as a rule, equipment is not set under pps, but under the required throughput

Answer 2

Consider the average load based on the performance of the channel / network for an average packet size of ~ 500 octets (4K bits) per packet (divide bits per second by 4000). The peak load can be significantly higher, about 500 bits per packet, but it occurs only on abnormal traffic (scans, floods, DDoS attacks, broadcast storms), i.e. you can lay the equipment with the expectation of an average load, but with the understanding that if you can create traffic to this equipment, the possibility of DoS arises, or to the maximum, then you will survive with anomalies.