combining rrd-s

I am monitoring and graphing two interfaces from two different switches.
I am in need of getting the 95th percentile the total traffic from the two
interfaces combined.
I am wondering if it is at all possible to get the two rrd-s and combine
them into one in order to do that calculation.

Any help would be greatly appreciated.

alban
-------------------------------------------------------------------------
Check out the new SourceForge.net Marketplace.
It's the best place to buy or sell services for
just about anything Open Source.
http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace