© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Connecting to Remote Networks Using Dedicated Connections for WANs

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Outline Overview Point-to-Point Communication Links Bandwidth High-Level Data-Link Control Protocol Point-to-Point Protocol Point-to-Point Communication Considerations Summary

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Leased Line

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v WAN Connection Bandwidth

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v HDLC and Cisco HDLC FCS = frame check sequence

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v PPP

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v PPP Encapsulation

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Point-to-Point Considerations Advantages Simplicity Quality Availability Disadvantages Cost Limited flexibility

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Summary A point-to-point (or serial) line can connect two geographically distant sites, which are usually leased from a carrier and are, therefore, often called leased lines. Bandwidth refers to the rate at which data is transferred over the communication link. In North America, point-to-point leased line bandwidth is typically specified as a DS number (DS0, DS1, and so forth) that technically refers to the rate and format of the signal. The HDLC protocol is one of two major data link layer protocols commonly used with point-to-point WAN connections. HDLC supports both point-to-point and multipoint configurations.

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Summary (Cont.) PPP provides a standard method for transporting multiprotocol datagrams over point-to-point links. The advantages of point-to-point communication links include simplicity, quality, and availability. The disadvantages of point-to-point communication links include cost and limited flexibility.

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v