帧中继协议栈-CCNA中文版PPT下载

帧中继协议栈 OSI 参考模型 帧中继 Physical Presentation Session Transport Network Data Link Application EIA/TIA-232, EIA/TIA-449, V.35, X.21, EIA/TIA-530 Frame Relay IP/IPX/AppleTalk, etc. * Purpose: This figure compares Frame Relay to the OSI model. Emphasize: The same serial standards that support point-to-point serial connections also support Frame Relay serial connections. Frame Relay operates at the data link layer. Frame Relay supports multiple upper-layer protocols.