Recently I rent a server and start playing for a while, but as soon as I bred animals in medium to large quantities (around 100 in total), the server disconnected me.
I checked the server log which says:

 lost connection: TranslatableComponent{key='disconnect.timeout', args=[], siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null, insertion=null}} 

I assumed I lagged out, so I checked the used bandwidth whilst playing and it kept using all my upload for no reason. Next thing I did I checked the traffic with Wireshark (see in the first and second picture) more than 1000 ACK packets per second, all of them 54 bytes long clogging my limited 70kBytes upload rate (they sum up to more than 54kbyte/s). Other way round I received the same amount of packets (thats what all the ACK packets are for) with usable data being between 6 and 12 bytes; the problem: every packet is around 100 bytes long what means that 90% of the data is not usable for minecraft at all. Due to that excessive amount of ACK packets for every 6-12 byte data packet (I assume movement/position update packets) I keep lagging out and disconnecting from that server.

Picture 1 shows the traffic from my client to the server. (notice the time and the frame no.)

Picture 2 shows the traffic from the server to my client. (The last packets are the ones that send the disconnect message I think) Also you can see the "Len=*" which is the actual data being sent without the overhead TCP produces.

So in conclusion I cannot play on a server with more that like 100-200 entities around me because it will spam me with update packets.