LESSON 6 – MAKING WAN CONNECTIONS
Wide Area Network (WAN) needs Wide Area Network (WAN) connections OVERVIEW
Analyzing requirements. Switched and dedicated link. Private or public Network. WIDE AREA NETWORK (WAN) NEEDS
Considerations: Primary and alternative uses. Locations that will participate. Geographical separation Services available Analyzing requirements
Considerations: Need of data to be transferred. Relevance/criticality Synchronous/asynchronous Real-time/batch Time frame for data to be transferred. Budget constraints.. Analyzing requirements
A switched WAN link is not active all the time. A dedicated WAN link is always up and running. Switched and dedicated link
Connection-based Packet-based Switched WAN link
Connection-based link: Forms a connection when needed. Makes fixed amount bandwidth available. Packet-based link: Sends data packets into a Network cloud. Packets follow number of paths to their destination. Switched WAN link
Used when: The connection needs to be up all the time. Economics of dedicated connection is cheaper than a switched connection. Dedicated WAN link
Private Network: Is exclusive to a company. Public Network: Allows the data of several companies to pass. Private or public Network
Public Network is used when: There is no problem if data takes longer to reach its destination. Delay between sites is unpredictable. One requires the lowest cost Network connection. Data security is unimportant. Private or public Network
Private Network is used when: There is full control over bandwidth use. A large, experienced staff maintains the public Network. Cost is not a concern. Data security is of prime concern. Full, reliable control over available bandwidth is possible. Private or public Network
WAN technologies: Plain Old Telephone Service (POTS) Integrated Services Digital Network (ISDN) Digital Subscriber Line (DSL) T-1/T-3 (DS1/DS3) Connections Asynchronous Transfer Mode (ATM) X.25 UNDERSTANDING WIDE AREA NETWORK (WAN) CONNECTIONS
Is ideal for low-bandwidth needs. Is usually the least expensive way to connect. Is carried over one set of twisted-pair wires. Has a maximum theoretical speed of 33.6Kbps. Transmits analog signals. Plain Old Telephone Service (POTS)
2 basic forms: Basic Rate Interface (BRI) Primary Rate Interface (PRI) Integrated Services Digital Network (ISDN)
Basic Rate Interface: 2B+D Two bearer channels carry data at speeds of 64Kbps per channel, which can also carry voice calls. The data channel carries call setup information and communication that manages the bearer 16Kbps. Integrated Services Digital Network
Primary Rate Interface: 24B+D. Different flavors available. Can carry a total of Mbps. ISDN connects are switched with fast call setup time. Integrated Services Digital Network
Asymmetric DSL (ASDL): 8Mbps of data received. 1Mbps of data sent. High-speed DSL (HDSL): 768Kbps and 2.048Mbps connection between two sites. Digital Subscriber Line (DSL)
Rate Adaptive DSL (RADSL): 600Kbps to 12Mbps of data received. 128Kbps to 1Mbps of data sent. Symmetric DSL (SDSL): Bi-directional rates varying from 160Kbps to 2.048Mbps. Digital Subscriber Line (DSL)
Very-high-speed DSL (VDSL): 51Mbps of data downstream. 2Mbps upstream. Digital Subscriber Line (DSL)
T-1/T-3 (DS1/DS3) connections DS1 connection: Has 24 DS0 channels. Can carry up to 1.544Mbps. Commonly called a T-1 connection.
T-1/T-3 (DS1/DS3) connections DS3 connection: Has 672 DS0 channels. Can carry up to Mbps. Commonly called a T-3 connection.
Asynchronous Transfer Mode (ATM) Is a multiplexed, cell-based Networking technology. Is very fast, (speed range: 155Mbps-622Mbps).
X.25 Is a packet-switched WAN connection. Data travels through an X.25 cloud. Transmits data securely and reliably.
SUMMARY Wide Area Network (WAN) needs: Analyzing requirements. Switched or dedicated link. Private or public Network.
Summary WAN technologies: Plain Old Telephone Service (POTS) Integrated Services Digital Network (ISDN) Digital Subscriber Line (DSL) T-1/T-3 (DS1/DS3) Connections Asynchronous Transfer Mode (ATM) X.25