The SMDSInterfaceProtocol (SIP) has been defined as the Switched Multimegabit DataService (SMDS) access protocol for the Subscriber Network Interface
(SNI). The Session Initiation Protocol (SIP) supports all SMDS features. It provides the necessary primitives, data structures, and elements needed to connect the subscriber terminal equipment
(CPE) to the network.IEEE 802.6Distributed Queue Dual Bus (DQDB), controls the user's access to the SMDS network. SIP Level 3 and SIP Level 2 operate as media access methods at the MAC sublayer of the data link layer
, and SIP Level 1 operates at thephysical
The SMDS Interface Protocol (SIP) receives and transfers the higher layerdata packets across the network. It controls access to the transmission medium and handles frame formation, addressing, error detection and data transport.