XBee ACK in mesh network

Hi,

I have a question regarding XBee ACK. I’ve read the Digi’s Manual (Series 2 XBee) and it says that ACK is being sent in unicast mode, and if transmitter doesn’t receive the ACK it will re-send the packet. Is this ACK being sent on MAC or Network layer. So if I have situation like

C ------------- R1 ------------- R2

And lets say C is tranmiter, sending packet to R2(through R1), will C get ACK from R1, or R2 ?

Regards

And lets say C is tranmiter, sending packet to R2(through R1), will C get ACK from R1, or R2 ?

The ACK comes from the receiver (R2), not the router (R1).

PaulS:

And lets say C is tranmiter, sending packet to R2(through R1), will C get ACK from R1, or R2 ?

The ACK comes from the receiver (R2), not the router (R1).

Even if R2 is also a router.

PaulS:

And lets say C is tranmiter, sending packet to R2(through R1), will C get ACK from R1, or R2 ?

The ACK comes from the receiver (R2), not the router (R1).

It doesn't really matter if the receiver is router or end device, I just wanted to know if the ACK is performed on MAC or Network layer. I thought it was Network layer but I was discussing it with my profesor and he claimed it is on MAC layer.

So it is on Network layer. Thanks PaulS