I would like to enable the QoS on the router. Do I config both routers (send and receive)
one IPLC between HK and TW. the routers are HKR1, TWR1
do we config QoS on both routers HKR1 and TWR1?
If you only configure the outgoing on one side, you'll only have QoS coming out of that site. The reason for configuring outbound on both sites is to have QoS conformity for your entire enterprise to the highest extent possible.
Let's say you only configure QoS on HKR1, and not TWR1. The packets coming out of HKR1 to TWR1 would be properly queued, classified, and QoS'd, and data/voice/video would be smooth coming out of HKR1 when it's headed outbound.
However, anything coming out of TWR1 would be FIFO queued, and your voice/video/data could be choppy for HKR1 to receive.
Without proper configuration on both sides, while QoS isn't totally useless, you won't see the best benefits from it.