Techniques are provided for implementing backhaul communications for an integrated access and backhaul node (IAB) operating in a wireless network. For example, an IAB node determines a first random access channel (RACH) configuration for a child node in the wireless network that is served by the IAB node. The IAB transmits a RACH configuration request message including the first RACH configuration to a parent IAB node, and receives, from the parent IAB node, a second RACH configuration complete message that includes a second RACH configuration that is based on the first RACH configuration for the child node. The IAB then performs backhaul communication with the parent IAB node using the second RACH configuration.