wrt54g v5 qos does not appear to be working broken
if you have the wrt54g router, and your using it with a voip service such as vonage or sun rocket, you may need to tune the QOS settings in the router in order to avoid being cut off or to have choppy distorted sounds. this qos will make sure that the router will do its best to give the most bandwidth to voice instead of data. the problem i had with the router was that the QOS (quality of service) does not appear to work correctly when using wireless. if your not using any wireless devices, it appears to work correctly. im not 100% sure but i believe you can have this working correctly by putting the mac address of the wireless device and setting it to low, and by setting the port number of the gizmo or voip device to high. note that the wireless device is only found by mac, and if you dont give it a priority, i think it defaults to high. the only problem with this, is that the default firmware on the device will only allow you to put two different devices at low priority. so if you have more than two wireless devices your screwed. someone on another site said to put the only the mac address of the gizmo instead and set that to highest priority, and not to use the other spot but it didn't appear to work for me, but you try it. if you are willing to upgrade your box to a better firmware that is better, check out here
to see if your box is upgradeable.