I was just about to post a question along the same lines, please don't think i'm trying to hi-jack the thread.

I have the VOIPo Linksys PAP2 TA, it does not have a LAN port, so the only choice is to put it behind the router.
I'd prefer to have it in front of the router to ensure the needed bandwidth always goes to the TA.

Is there any way to configure this TA to grab the max bandwidth or it is router dependent? If router dependent, any one know how this is accomplished?