I have encountered a similar problem using the OpenWRT WhiteRussian 0.9 x-wrt image on my Linksys WRTSL54GS.
My ISP, Qwest, Advertises a 1536 kbps down, 896 kbps up connection. My DSL Modem indicates that it has a 1536/896 connection. Now, if one allows 15% for overhead, I should see 1305 kbps down and 761 kbps up when communicating with devices over the internet.
I noticed that when I had my WRTSL54GS OpenWRT box between my PC and the DSL Modem, I would get 1289/464 kbps on average. I checked out the QOS setting in /etc/config/qos:
/etc/config/qos
# INTERFACES:
config interface wan
option classgroup "Default"
option enabled 0
option upload 512
option download 3072
...
Ah ha! Taking 15% overhead off of a 512 kbps up connection would be about 464 kbps. So, I matched my ISP's advertised rates:
/etc/config/qos
# INTERFACES:
config interface wan
option classgroup "Default"
option enabled 0
option upload 896
option download 1536
...
That fixed my upload problem. I could send data at 760 kbps, but I could only receive data at an average of 904 kbps. After testing different QOS configurations, I found for my ISP's advertised rates, the QOS settings of 3072/896 worked best so that out of my 1536/896 connection I get an average 1258/635 kbps connection to various servers with a maximum transfer rate of 1312/760 kbps to my ISP, very close to a 15% drop due to overhead. So, if anyone is still reading, my final settings for Qwest's 1536/896 package are:
/etc/config/qos
# INTERFACES:
config interface wan
option classgroup "Default"
option enabled 0
option upload 896
option download 3072
...
(Last edited by bkloppenborg on 29 Aug 2007, 05:15)