after a bit of idling, my LP system started sending massive amounts of packets, some of which seem to be overbearingly large; this results in the client being unable to connect because of "badly compressed packets"

very short packet log snippet: packets.txt

Are you using pipes connected to some machine or block of other mods? Have you tried analyzing what pipe might cause this packet flood? The log, sadly, does not help all that much other than our "faulty" packet is 26 bytes long and it seems to be the same packet type being send over and over again.

Afaic there are no large packets involved, but instead there are way too many small packets. This basically is a DoS issue and would explain why others cannot connect.

I just don't know anymore.
after breaking a single fluid supplier mk2 pipe the traffic dipped into the "playable" zone for a good minute, but then it shifted into the next gear and started viciously spamming tileentity updates. dismantling half the system cut down on P18 from LP, making it go down from ~180kb/s to ~85kb/s avg,
can't say more because I forgot I didn't have backups on hand and broke all the pipes like an idiot (which brought the traffic down to a whole 3kb/s)