Glossary240 CSX200 Family User’s GuideOSI — Open System Interconnection. An international standard developed by ITU (formallyCCITT) and ISO (International Organization for Standardization) to facilitate data networkingmulti-vendor interoperability. The OSI Reference Model defines seven layers, each providingspecific network functions.Packet — A group of data that includes a header and usually user data for transmission through anetwork.Ping (Packet Internet Groper) — An echo message, available within the TCP/IP protocol suite,sent to a remote node and returned; used to test the accessibility of the remote node.PPP (Point-to-Point Protocol) — A Data Link layer protocol that provides asynchronous andsynchronous connectivity between computer/network nodes. Includes standardization for securityand compression negotiation.Q.921 — ISDN Data Link layer specification for the user-to-network interface.Q.931 — ISDN specification for call set-up and signaling on ISDN connections.RFC — Request for Comment. Documentation describing Internet communicationsspecifications (e.g., Telnet, TFTP). Often these RFCs are used to achieve multi-vendorinteroperability during implementation.RJ11 — Standard 4-wire connectors for telephone lines.RJ45 — Standard 8-wire connectors used for ISDN lines and 10 BASE-T connections.RIP (Routing Information Protocol) — Protocols used in IP and IPX for broadcasting open pathinformation between routers to keep routing tables current.Routing — A Network layer function that determines the path for transmitting packets through anetwork from source to destination.RS-232 — EIA standard specifying the physical layer interface used to connect a device tocommunications media.Serialization Frames — Frames sent out by servers under IPX to check whether illegal copies ofNetWare are in use on the network.Service Advertising Protocol — Protocol used in IPX for broadcasting information aboutservices available on the network, such as file servers, CD-ROM drives and modem pools.
