Need Helping Setting Up Qos Using Tomato Firmware

Hi,

I have a few questions about setting up QOS in order to prioritize voip and video chats using a router that has tomato firmware.

1) My connection is 50/10. What do I type for Max Bandwidth Limit in the kbit/s (Set to measured bandwidth less 15-30%) setting? I think 50mbit = 50,000 kbit/s but I'm not sure.

2) These are the QOS categories:

Service

VOIP/Game

Media

Remote

WWW

Mail

Messenger

FileXfer

P2P/Bulk

Crawl

Do I need to prioritize VOIP/Game, Messenger & Media in order to prioritize voip & video chats through Facebook messenger & FaceTime?

3) When I prioritize each category, does the total percentage I select for each have to add up to 100% when I add them all up? For example:

VOIP/GAME - 50%

Media - 30%

Messenger = 10%

Crawl - 10%

Or does the percentage for each category determine the percentage of the bandwidth that will be given to that specific category when it's being used?

Thanks.