Bandwidth Limit

[atatham]

Hi,

We have a new leased line running at 20Mbit over a 100Mbit bearer. We have setup a Debian Linux distribution to act as a router. We have also used IPCop, MonoWall etc but all exhibit the problem below.

We can download at 20Mbit/s perfectly however when we attempt to upload we can at best achieve only 6/7Mbit.

Our service provider says that due to the bearer and the NIC running at 100Mbit we must shape our outgoing traffic to 20Mbit/s or we will have problems achieving the speed. They have offerred an example Cisco configuration but can't help with Unix.

I have used TC to limit the outgoing link to 20Mbit and various other speeds but it has no effect. I have tested the TC configuration by filtering the LAN interface and it has the desired effect of throttling the download speed.

Does anyone have any advice. I can't believe I can't get something as powerful as Unix to do what a Cisco with a 200Mhz processor can do. Sample TC configuration below:

SPEED=20Mbit
DEV=ethx

tc qdisc del dev $DEV root
tc qdisc add dev $DEV root handle 1: cbq avpkt 1000 bandwidth 100Mbit
tc class add dev $DEV parent 1: classid 1:1 cbq bandwidth $SPEED rate $SPEED allot 1514 cell 8 maxburst 20 avpkt 1000 bounded
tc filter add dev $DEV parent 1: protocol all u32 match u32 0 0 flowid 1:1
tc qdisc add dev $DEV parent 1:1 sfq perturb 10

Thank you!

[jmmr84]

Hi atatham, can you post the Cisco configuration?. I have a lot of experience with both and maybe i can help you.

Best Regards.

[atatham]

Thanks jmmr84. The working Cisco configuration is:

policy-map 20m-shape-out
class class-default
shape average 20000000 80000
bandwidth 20000
!
interface FastEthernet0/0
ip address X.X.X.X
no ip proxy-arp
speed 100
full-duplex
no cdp enable
service-policy output 20m-shape-out