Spillover routing?

[Bruce M. Simpson]

Rajkumar S wrote:
> Hi,
>
> I have a low cost 128kbps and a high cost 512 kbps link to internet.
> Is it possible to do a "spillover" routing so that the high cost link
> is used only when the low cost link is, say, used more than 80%.
This feature is almost certainly not going to be present in the base 
system. What you would need to do to implement this is to configure a 
part of the kernel to perform bandwidth measurements and make an upcall 
to bring up the other link in a dial-on-demand style configuration. Add 
NAT into the mix and it gets even more interesting. I believe pf+altq 
may have the potential to do this however I could not help you with 
where to begin re configuring it to do so, so I wish you best of luck in 
your research.

Regards,
BMS