SPP Transmission Method or Sequenced Packet Protocol:
SPP is a Xerox Network Systems (XNS) protocol for sequenced and connectionless packet delivery support. It is a network transport protocol providing reliable packet delivery with flow control.
SPP is similar to Transmission Control Protocol (TCP)
A key technical difference is that SPP packets count sequence numbers but not bytes.
SPP manages several functions. It uses destination identification (ID) numbers for transport link target end definition.
It also uses sequence numbers for transmitted and sequenced packet maintenance. SPP acknowledges allocated numbers for previous packets, which ensure destination reception alongside indicating successful transmission completion.