With the CLIP, (as mentioned before), inter-LIS communications have to go through routers. This is not an optimal solution when both nodes communicate with each other are attached to the same ATM network. A mechanism is needed for an end system to resolve the IP address of another end system in a foreign LIS into the corresponding ATM address. The NBMA (Non Broadcast, Multi Access) NHRP protocol, developed by the IETF, overcomes this limitation and provides this mechanism.