PenUltima Online

Can I please get an accurate meaning of what queued data mode means and what it implies?

I am trying to track down random lag problems that effect a lot of players and we see queued data mode fairly often on the console. eg:

Client $66: Switching to queued data mode (xx, yy bytes)
Leaving queued mode (zzzz bytes transmitted)

Whenever we see the message, that player reports lag but it doesn't mean others will have the lag.

Pings to the player don't seem to indicate a laggy internet.

Because of this setting: EnableFlowControlPackets 0
I had assumed that pol was just going to send the data out anyway and not have to queue it, but obviously not in all cases.

So to the question:
Can queued data mode be caused by pol/script lag or does the queued data mode mean that pol is ready long before the client is ready to accept the data? A better understanding of this message would help me a lot.


Our shard cpu doesn't appear to be an issue. Lots of spikes over time but no flat 100% cpu.
We have 1Mbps bandwidth out to the internet.
I have had a close look at all my critical scripts but don't think it's them.
The reports of lag started around the start of the new year.

Queued data mode means that the client connection is experiencing lag. It basically means that POL needs to send out the information but there isn't enough of a connection to send it out on time (lag). EnableFlowControlPackets has absolutely no connection to this. FlowControlPackets as I understood them were pause and unpause packets supported by older clients that made the client completely stop, receive all of the information it had to receive, then restart making it all seem like it all happened immediately in one jump (i.e. moving a ship and everything moves at the exact same time instead of some things moving in one burst then the others drag along in another burst)

Appreciate the reply CWO.