The document discusses wide area networks (WANs) and how they connect remote sites over long distances. It covers WAN connection types, components, and cabling used at layer 1. Layer 2 encapsulation protocols are explained, including HDLC, PPP, SLIP, X.25, Frame Relay and ATM. The summary restates that WANs connect distant sites, different connection options exist depending on needs, and common layer 2 protocols are used to encapsulate data for transmission over WAN links.

1. Establishing Serial Point-To-Point Connections
Introducing Wide-Area Networks
Lecture 8
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2. Outline
• Overview
• WAN Overview
• WAN Connection Types
• WAN Components
• WAN Cabling
• Layer 2 Encapsulation Protocols
• Summary
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3. WAN Overview
• WANs connect remote sites.
• Connection requirements vary depending on user
requirements, cost, and availability.
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4. WAN Connection Types: Layer 1
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5. Interfacing Between
WAN Service Providers
• Provider assigns connection parameters
to subscriber
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6. Serial Point-to-Point Connections
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7. Typical WAN Encapsulation Protocols:
Layer 2
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8. Summary
• A WAN makes data connections across a broad geographic
area so that information can be exchanged between distant
sites.
• WAN connection types include leased line, circuit-switched,
and packet-switched.
• WAN components that the provider assigns to your
organization include CPE, demarcation, local loop, CO
switch, and toll network.
• Cisco routers support the EIA/TIA-232, EIA/TIA-449, V.35,
X.21, and EIA/TIA-530 standards for serial connections.
• To encapsulate data for crossing a WAN link, a variety of
Layer 2 protocols can be used, including HDLC, PPP, SLIP,
X.25/LAPB, Frame Relay, and ATM.
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