Our WAEs are only connected via internet vpn tunnel and all is good. However, We have observed that when we start data transfer over VPN, its consumed our whole bandwidth (6Mbps) which make other process slower. Can we put some cap at say 4Mbps~5Mbps so that other process can run smoothly.
The TFO functionality in WAAS will attempt to leverage all of the available WAN bandwidth. You could try artificially lowering the optimized send/receive buffers, but that's not recommended.
Is it possible for you to use network-based QoS?