Bonding 2 adsl for voip

Hi

I found this link http://www.mikrotik.com/testdocs/ros/3.0/interface/bonding_content.php#.2 and wanted to know if this is an ideal example if i wanted to bond my 2 adsl lines to get a bigger upload and to allow for more simultaneous calls to be made via voip. Each adsl can handle 4megs download but only 512Kb upload. If i bond it would i have a 1 meg upload or would it be better if i create rules for port 5060 and have traffic routed to another interface if that interface comes close to 512Kb?

Any advise welcome

Thanks

What you need is mlppp.

http://www.mikrotik.com/download/Mikrotik_no010.pdf

Read a little bit of mlppp and ask your isp if they support it.

Jorge