Traffic-shaping on the LAN interface?

[DialerString_2]

Hi,

There is a remote server that downloads info from a server here at HQ. When the dowloads start the rxload on the S0/0/0 interface jumps to 98 percent or so; rxload 250/255. I needed to limit the bandwidth utilization between the servers, so I added the below line to the LAN interface on the remote router.

By adding the command, it reduced the download utilization -which is what I wanted.

access-list 185 permit ip host 10.6.27.1 any

!

int f0/0

traffic-shape group 185 10000 8000 8000 1000

Question:

How would applying this to the LAN interface cause the download utilization (Coming from s0/0/0) to decrease?

[Roman Rodichev]

I assume 10.6.27.1 is the IP of the server in HQ. You have effectively limited bandwidth utilization to 10kbps for traffic returning from 10.6.27.1 to your remote site server on the remote router LAN interface. Traffic shaping will use token bucket to measure the packet rate and then buffer/queue excess packets causing packet delays and some packet drops in your TCP transfer when it reaches 10kbps. The end stations use TCP flow control mechanisms to react to these delays and drops by slowing down the transfer rate. You could do traffic-shaping on any hop in your network resulting in pretty much the same behavior.

[DialerString_2]

First, thanks for the quick response Roman -

So the remote router (South Carolina) will slow down the xfer rate when the traffic enters the WAN interface or before it leaves the F0/0 LAN interace -where the shapping is applied -?

[Roman Rodichev]

it's a snowball effect... remote site router will "slow down" traffic on the LAN interface, which will cause HQ server to slow down traffic sent to the remote site router, effectively causing traffic to slow down on the WAN

[DialerString_2]

Bet... and Roman thanks for your help on this!