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Graphics Interchange Format  |  1997-01-16  |  54KB  |  526x323  |  4-bit (16 colors)
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OCR: FRAME RELAY WAN CARRYING SNA TRAFFIC VIA DATA-LINK SWITCHING SNA Connection SNA connection between router and host TCP connection maintained between router between routers and host Host A to host B "virtual" SNA connection SNA nost A DLSw CSU/DSU CSD/DSU DLSW souter A outer B SNA host A: Frame relay cloud In a frame relay WAN, leased lines aren't point to point One end terminates at a UPW site and the other in the cloud. Frame relay access device (FRAD) SNA node C Figure 2. In this DLSw network, when host A initiales a data transfer to host B or C, router A intercepts and verifies the connection, returning a signal to host A to confirm the connection. The router is responding on behalf of the receiving host system. Router A then establishes a TCP connection with the receiving host's router and transmits the data through the cloud.