Abstract: A novel ATM network provided which includes one or more ATM gateways for interfacing a plurality of T1 or fractional T1 signals with a higher bandwidth ATM network switch. In order to provide high speed and bandwidth utilizing relatively inexpensive and standard components, the data is stored in a memory, such as a video RAM, and pointers are utilized to indicate the type of each piece of data stored in the memory, including its priority for transmission to an ATM switch. In one embodiment of this invention, a plurality of pointer pools are used, each corresponding to a data type having a given priority. Pointers are placed into an appropriate one of the pools to define the order in which data will be transferred to the ATM switch in accordance with the priority of the data type and the receiving bandwidth of its destination in the ATM network. In one embodiment an HDLC controller is used which is suitable for framing a plurality of channels of data received on an incoming data path, such as a T1 channel.