FastPath allows the DSLAM to pass the data received from you to the first hop router without performing any error correction. As a result, marginal lines could experience an increase in packet loss and decrease in sync stability (i.e. frequent sync loss). However,
FastPath has lower ping times, especially to the first hop router.
Interleaving effectively reduces packetloss. This is usually implemented on noisy lines. It corrects errors in the data stream beforwe passing any data onto the gateway/router.
This will generally increase ping times.
Don't get these two confused. You want FastPath for gaming
