[nsp] Load Balancing with BGP over unequal-cost circuits

[Rubens Kuhl Jr.]

| Serial0/1 is up, line protocol is up
|      reliability 255/255, txload 242/255, rxload 211/255
|   Output queue 971/4096, 138782 drops; input queue 0/75, 54 drops

| Serial0/2 is up, line protocol is up
|      reliability 255/255, txload 211/255, rxload 209/255
|   Output queue 1023/1024, 3212912 drops; input queue 0/75, 60 drops


It seems that the output links are both quite congested, so some of the
load-balancing effect you are seeing is due to a 50%/50% balancing that puts
50% of the sessions on a more congested link, but these sessions converge
(TCP-backoff) to less bandwidth per session.

As some have already pointed out, what the router is doing is next-hop load
balancing, caused by these routes:

|ip route 192.168.255.202 255.255.255.255 Serial0/1
|ip route 192.168.255.202 255.255.255.255 Serial0/2

Try adding another route that would go thru the 2Mbps link and then you'll
have a 33%/66% balancing that is more representative of the scenario.

Rubens Kühl Jr.