Ongoing lagging issues when playing with others

when playing with others assuming I'm able to connect and keep a somewhat stable connection I notice a lot of lagging at times. luckily we are not in survival or if we are it's on peaceful. and this could come from after doing any action. trying to load the chat screen, opening the inventory, opening or closing a storage chest or just walking around. no it's not from big builds or multiple redstone creations as this was on a brand new world. (this is from the original ticket)

After the last update before caves and cliffs update 1 came out I had been playing with others on another world and the lagging got so bad I had to leave and come back. There were also multiple times where the screen would just sit there loading before getting an error message and the game crashing. I was doing test runs on a new world and even the world was lagging real bad. I'm not sure what it could have been as this was a world I was having previous problems with but also I'm using a texture pack but at the same time I've had no problems with the texture pack after downgrading the resolution to the lower setting.