Bandwidth limit by device/protocol

[infamoose]

Hi,

I have read some of the forum threads but rather confused as to what I should be doing here. First my setup:

WAN: Intel NIC
LAN: Intel NIC

Now my question:
I have a PBX behind this firewall, it currently requires two (2) ulaw/alaw connections at anytime. According to other threads the recommended bandwidth for the uLaw codec is 87.2 kbps – in both directions -- which includes overhead. What is the best practice to approach this? Would like to prioritize (actually reserve full time) 175 kbps on the WAN connection for both ingress and egress.

How this is accomplished is providing me with a bit of trouble. Once the reservations are created on the WAN connection, do I need to worry about QoS for VoIP based protocols or will the WAN reservation do the job for me?

Also, once the reservation is in place will the remainder of my network bandwidth be available per usual to other protocols? Web / torrents / etc. ?? Any help is greatly appreciated.