How to Identify source node of received packet of Zigbee in arduino?

I am sending packets from two routers to a coordinator in my xbee network. I want to know which router send this received packet at coordinator. I am using API mode for both Routers and Coordinator.

I am not sending any identity in packet data, its just a random data. Is there any way to identify source of packet from its frame details..?

Kindly guide me, Thanks.