A packet switching network system for use in transferring information that is in the form of packets and including an originating device and a destination device for communicating therebetween through a packet switching network, the originating device including a sending device having a first buffer with a predetermined first buffer size, the first buffer being used to store information that is to be sent to the destination unit, the sending device for sending a request packet including the first buffer size, through the packet switching network, to the destination device, the destination device including a receiving device having a second buffer with a predetermined second buffer size, the second buffer size being used for storing information that is received from the originating device, the receiving device for receiving a request packet including the first buffer size from the originating device, determining whether or not the received first buffer size is supported by the destination device, and accordingly sending back a response, through the packet switching network, to the originating device, wherein, during initialization, the originating device and the destination device enter into negotiations as to a mutually-acceptable buffer size that is to be used for information transfer by the packet switching network system.