I have two point-to-point t1 lines, with a 1720 and a 2621 on the ends. I was under the impression that by simply having routes of equal costs going through both t1s, that packets would be spread among them, at least to some extent.
However, in practice it doesn't work that well. Any one host only seems to be able to use a max of about 1.5mbits, and even with multiple connections from various hosts, I never get to more than about 2.0 or 2.3 mbits total throughput. Looking around, I see that nearly all references to load-balancing t1s as using CIF, and our feature set (or IOS version) doesn't appear to support the commands that they utilize.
So... do I need a certain feature set in order to make this work, or will I need to look at upgrading the IOS version, along with accompanying flash and memory?