SDISC Assembler Call - NetEx

NESiGate Offload NETEXThis NETEX product is similar to the DX NETEX product in that processing is removed from the host. TheNETEX program resides as either LAN Offload or Channel Offload software running in the NESiGateadapter. Only the Hxx7IP Requester or user interface program resides on the host. In this implementation,Hxx7IP.NETEX and the ISO ModelIn creating NETEX, Network Executive Software followed the guidelines set by the International StandardsOrganization (ISO) for Open Systems Interconnection (OSI). Open Systems Interconnection refers to the exchangeof information among terminal devices, computers, people, networks, and etcetera that are open tocommunication with one another.The ISO model is composed of seven layers. Each layer interacts only with adjacent layers in the model (seeTable 1). By using this modular structure, the internal function of each layer is self-contained and does notaffect the functioning of other layers.Table 1 . ISO ModelLayerApplicationPresentationSessionTransportNetworkData LinkPhysicalMajor FunctionsHigh level description of data to be transferred and the destination involvedSelect data formats and syntaxEstablish session connection, report exceptions, and select routingManage data transfer and provide NETEX-to-NETEX message deliveryPoint-to-point transfer, error detection, and error recoveryData link connection, error checking, and protocolsMechanical and electrical protocols and interfacesAlthough each layer physically interacts only with adjacent layers, each layer appears to communicate directlywith the corresponding layer of the other model. Figure 2 illustrates this concept.Page 4 Introduction MAN-REF-H307IP-04