The Internet and Its UsesCisco Public * Cisco Public Describe how the Cisco Enterprise Composite Model (ECNM) provides integrated services over an Enterprise network. Describe the key WAN technology concepts. * Cisco Public WAN A WAN is a datacommunications network that operates beyond the geographic scope of a LAN. WAN allows the transmission of data across greater geographic distances WANs use facilities provided by a service provider, or carrier. WANs use serial connections. LAN connects computers, peripherals, and other devices in a single building or other small geographic area * Cisco Public Cisco Public Cisco Public Cisco Public * Cisco Public Describe How ECNM Provides Integrated Services over an Enterprise Network Explain the purpose of Cisco Enterprise Architectures * © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public WAN functions in terms of the OSI Reference Model The physical layer (OSI Layer 1) protocols describe how to provide electrical, mechanical, operational, and functional connections to the services of a communications service provider. * ATM – asynchronous transfer mode HDLC – high level data link control – used instead of clock in RT to RT comm before © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public * Graphic 1.2.2.1 If space permits add graphics 1.2.2.2 & 1.2.2.3 (if forced to make a choice between the 2 graphic pick 1.2.2.2) PSTN devices – multiplexer (time division and frequency division multiplexing) used in switches © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public WAN physical-layer protocols describe how to provide electrical, mechanical, operational, and functional connections for WAN services. The WAN physical layer also describes the interface between the DTE and the DCE. © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public Key WAN Technology Concepts * Cisco Public Switching technologies used for WANs in an Enterprise setting A circuit-switched network is one that establishes a dedicated circuit (or channel) between nodes and terminals before the users may communicate. PSTN and ISDN are two types of circuit-switching technology that may be used to implement a WAN in an enterprise setting. Packet switching splits traffic data into packets that are routed over a shared network. Packet-switching networks do not require a circuit to be established, and they allow many pairs of nodes to communicate over the same channel. Packets are divided and sent through available connections. * Packet-switching for computers (SMS and email) We can’t use packet-switching for telephone calls because it divides packets We can use circuit-switching for transmitting packets Alternative graphic can be found at the following URL (not necessary to use – just a thought): http://www.cisco.com/image/jpg/en/us/guest/products/ps6438/c1244/cdccont_0900aecd802c2010_0900aecd802c2010-08.jpg graphic 1.2.4.2 Delays (latency) and variability of delay (jitter) are greater in packet-switched than in circuit-switched networks. This is because the links are shared, and packets must be entirely received at one switch before moving to the next. © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public * Cisco Public Enterprises use leased line services to provide a WAN connection * Leased line uses dedicated line Telephone lines use analog communication © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public * Cisco Public * Cisco Public * The objective stated above does not make sense to me. Reword the above objective as follows: List factors to consider when selecting a WAN connection Graphic 1.3.5.4 Cisco Public A WAN is defined as A data communications network that operates beyond the geographic scope of a LAN WAN primarily operate on layer 1 & 2 of the OSI model WAN technologies include Cisco Public Cisco Enterprise Architecture This is an expansion of the hierarchical model that further divides the enterprise network into Physical areas Logical areas Functional areas Selecting the appropriate WAN technology requires considering some of the following: WAN’s purpose © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public