ocr: BEMORKUVERCOMPANISON SNA: OSI ICPXIP Application Application. Application presentation Presentation presentation Logical unit and session session physical unit Transport ICP Path contro Network P Datalink Data link Data ink Elysrea Plvsical Flysical Souce Bar newrks, megatig SVA SEZMNTRNAOYNGIANNS- Figure 1. This comparison oft the SNA, OST, and TCP/IP network models illustrates difjerences in the tharee approaches, primarily in the top-halflayers.