1. Internetworking Concepts Overview
Chapter 2
Internetworking Concepts Overview
Purpose: This chapter reviews general networking theory and introduces students to some of Cisco’s product line.
Timing: This chapter takes approximately 1.5 hours to present.
Note: This section has a product selection tool laboratory exercise at the end.
Contents:
Objectives—This section explains what the student will be able to do at the end of this chapter.
Defining Network Components—This section displays where devices are placed in the network.
Mapping Business Needs to a Hierarchical Model—This section describes the heirarchical model used in network design.
OSI Model Overview—This section reviews the OSI model.
Communicating Between Layers—This section describes encapsulation and de-encapsulation.
Written Exercise 1—This section has a written exercise to test the students’ knowledge of the OSI model.
Physical Layer Functions—This section describes the physical layer of the OSI Model.
Data Link Layer Functions—This section describes the data link layer of the OSI Model.
Network Layer Functions—This section describes the network layer of the OSI Model.
Transport Layer Functions—This section describes the transport layer of the OSI Model.

2. Objectives
On completion of this chapter, you will be able to perform the following tasks:
Describe how data traffic is exchanged between source and destination devices
Identify the roles and functions of a hub, switch, and router, and where they best fit in the network
Select the appropriate Cisco equipment for a given set of network requirements
Purpose: this figure states the chapter objectives.
Emphasize: Read or state each objective so each student has a clear understanding of the chapter objectives.

3. Defining Components of the Network
Home Office
Mobile Users
Note: The two connections between the same sites are for redundency.
Emphasize: The type of connections typical in a home office may be asynchronous dial-up or ISDN BRI. Mobile users only use dial-up. Branch offices and Central sites have the connections just stated. In addition they may have leased lines and packet switched services, to list just a few.
Internet
Branch Office
Main Office

4. Defining the Components of a Network (cont.)
Emphasize: Breaking up the corporate network into smaller components makes network design and management more managable.
Transition: The next few pages a heirarchical model used in network design.
Branch Office
Floor 2
Server Farm
ISDN
Floor 1
Telecommuter
Remote
Campus

5. Network Structure Defined by Hierarchy
Core Layer
Distribution
Layer
Purpose: This page introduces the hierarchical model.
Emphasize: This model has evolved from real-life experience in configuring very large networks.
Campus network designs have traditionally placed basic network-level intelligence and services at the center of the network and shared bandwidth at the user level. Over the past few years distributed network services and switching has migrated to the user level.
One approach to ensure a level of network performance is to segment the network into layers of functionality. These layers of functionality are defined by the following layers:
Access
Distribution
Core Layer.
This model permits enables designers to define building blocks that interconnect users and services.
It is important to remember that the hierarchical model refers to conceptual layers that provide functionality. The actual demarcation between layers does not necessarily have to be a physical link. This demarcation can also refer to the backplane of a particular device
Transition: The following describes the access layer of the hierarchical model.
Access
Layer

6. Access Layer Characteristics
Purpose: This page defines local services.
Emphasize:
A local service is when the entities that provide these common functions reside on the same subnet or virtual network as the user.
Local services remain in specific area of the network.
Traffic to and from local services is confined between a server, a switch, and an end user.
Local traffic does not enter the network backbone or move through a router.
Local services are confined to a common workgroups.
Transition: The following describes remote services
End station entry point to the network

7. Distribution Layer Characteristics
Access Layer Aggregation Point
Routes traffic
Broadcast/Multicast Domains
Media Translation
Security
Possible point for remote access
Distribution Layer
Purpose: This page defines enterprise services.
Emphasize:
Enterprise services are services common to all users.
Examples of enterprise services would be , Internet access, or video conferencing.
Enterprise servers and services exist within a separate subnet placed close to the backbone of the network. Placing the enterprise servers close to the backbone ensures the same administrative distance from each user; however, this also means that all traffic going to an enterprise server crosses the backbone.
Because enterprise services exist outside of the broadcast domain of the end user, these services are surrounding by Layer 3 functionality.
The Layer 3 switch allows servers to be centralized with no performance penalty, eliminating the cost of numerous server repositories.
Layer 3 devices also provide a level of security which protects the information stored on the servers.
Transition: The following describes the multilayer model.

8. Core Layer Characteristics
Purpose: This page discusses the characteristics of the core layer.
Emphasize:
The sole purpose of the core layer of the network is to switch packets as fast as possible.
Routing, access lists, and packet filtering should not take place in the core as these functions will slow the data packet transfer rate.
Transition: The following discusses how Cisco products fit with the multilayer design.
Fast transport to enterprise services
No packet manipulation

9. OSI Model Overview Application Application (Upper) Layers Presentation
Session
Layer 1 of 2:
Purpose: This figure orients the students to the OSI model.
Emphasize:
This model should be a review for students who attend this course. Gage the depth of your discussion around the knowledge of the students.
Transition: The following layer discusses the lower layers of the OSI reference model.

10. OSI Model Overview Application (Upper) Layers Presentation Session
Transport Layer
Layer 2 of 2:
Purpose: This figure orients the students to the next set of concepts.
Emphasize:
The Data Link layer of the OSI reference model is implemented by Switches and Bridges. These devices encapsulate date in “frames”.
The Network layer of the OSI reference model is implemented by Routers. These devices encapsulate data in ‘packets’.
The Transport layer of the OSI reference model is implemented by various protocols; one of which is TCP. TCP uses ports and encapsulates the data in ‘segments’.
Network Layer
Data Flow
Layers
Data Link
Physical

11. Role of Application Layers
EXAMPLES
Telnet
HTTP
Application
User Interface
Slide 1 of 4:
Purpose: This figure orients the students to the application layer.
Emphasize:
This layer discusses network applications rather than computer applications. So, applications such as spreadsheets, word processors, or presentation graphics are not the applications being described here. Network applications may be applications that support, electronic mail, file transfer, remote access, network management, and so on.
Transition: The following discusses the presentation layer.

12. Role of Application Layers
EXAMPLES
Telnet
HTTP
Application
User Interface
How data is presented
Special processing such as encryption
ASCII
EBCDIC
JPEG
Presentation
Slide 2 of 4:
Purpose: This figure orients the students to the presentation layer.
Emphasize:
This layer discusses code formatting, data presentation standards, and conversion.
Transition: The following discusses the session layer.

13. Role of Application Layers
EXAMPLES
Telnet
HTTP
Application
User Interface
How data is presented
Special processing such as encryption
ASCII
EBCDIC
JPEG
Presentation
Keeping different applications’
data separate
Operating System/
Application Access
Scheduling
Session
Slide 3 of 4:
Purpose: This figure orients the students to the session layer.
Emphasize:
This layer coordinates applications as they interact on different hosts. Examples of session-layer protocols include: NFS, SQL, RPC, and so on.
Transition: The following displays the lower layers.

14. Role of Application Layers
EXAMPLES
Telnet
HTTP
ASCII
EBCDIC
JPEG
Operating System/
Application Access
Scheduling
Application
User Interface
How data is presented
Special processing such as encryption
Presentation
Keeping different applications’
data separate
Session
Slide 4 of 4:
Purpose: This figure orients the students to the entire OSI model stack.
Emphasize:
The lower layers sit below the upper three layers. The remainder of this course is focused on the lower layers.
Transition: The following discusses the physical layer of the OSI reference model.
Transport Layer
Network Layer
Data Link
Physical

15. Role of Data Flow Layers
EXAMPLES
Slide 1 of 5
Purpose: This figure orients the students to the physical layer of the OSI Model.
Emphasize:
The physical layer specifies the electrical, mechanical procedural, and functional requirements for activating, maintaining, and deactivating the physical link between systems.
Certain physical standards are associated with certain data link standards. For example, is used with data link standard for Ethernet. It is not used in WAN connections. This is covered more in-depth later in the course.
Transition: The following discusses Layer 2, the Data Link layer, of the OSI reference model.
Move bits between devices
Specifies voltage, wire speed and pin-out cables
EIA/TIA-232 V.35
Physical

16. Role of Data Flow Layers
EXAMPLES
Slide 2 of 5:
Purpose: This figure orients the students to the data link layer.
Emphasize:
The data link layer provides data transport across a physical link is and physical and data link Ethernet protocol. It is used with the standard.
Transition: The following discusses Layer 3, the network layer, of the OSI reference model.
Combines bits into bytes and bytes into frames
Access to media using MAC address
Error detection not correction
802.3 / 802.2
HDLC
Data Link
Move bits between devices
Specifies voltage, wire speed and pin-out cables
EIA/TIA-232 V.35
Physical

17. Role of Data Flow Layers
EXAMPLES
Provide logical addressing which routers use for path determination IP
IPX
Network
Slide 3 of 5:
Purpose: This figure orients the students to the network layer.
Emphasize:
Network layer is where IP occurs.
Transition: The following discusses Layer 4, the transport layer, of the OSI reference model.
Combines bits into bytes and bytes into frames
Access to media using MAC address
Error detection not correction
802.3 / 802.2
HDLC
Data Link
Move bits between devices
Specifies voltage, wire speed and pin-out cables
EIA/TIA-232 V.35
Physical

18. Role of Data Flow Layers
EXAMPLES
Reliable or unreliable delivery
Error correction before retransmit
TCP
UDP
SPX
Transport
Provide logical addressing which routers use for path determination IP
IPX
Network
Slide 4 of 5:
Purpose: This figure orients the students to the transport layer.
Emphasize:
The Transport layer of the OSI reference model is implemented by various protocols; one of which is TCP. TCP uses ports and encapsulates the data in ‘segments’. TCP is connection oriented so it offers reliable service. The other major transport layer protocol discussed in this course is UDP. It offers speed but no reliability because it is connectionless.
Transition: The following presents the entire OSI stack again.
Combines bits into bytes and bytes into frames
Access to media using MAC address
Error detection not correction
802.3 / 802.2
HDLC
Data Link
Move bits between devices
Specifies voltage, wire speed and pin-out cables
EIA/TIA-232 V.35
Physical

19. Role of Data Flow Layers
Application
Presentation
EXAMPLES
Session
Reliable or unreliable delivery
Error correction before retransmit
TCP
UDP
SPX
Transport
Provide logical addressing which routers use for path determination IP
IPX
Network
Slide 5 of 5:
Purpose: This figure reviews the entire OSI model stack.
Emphasize:
The upper layers sit above the lower layers.
Transition: The following discusses encapsulation and de-encalsulation.
Combines bits into bytes and bytes into frames
Access to media using MAC address
Error detection not correction
802.3 / 802.2
HDLC
Data Link
Move bits between devices
Specifies voltage, wire speed and pin-out cables
EIA/TIA-232 V.35
Physical

20. Encapsulating Data PDU Segment Transport Network Packet Data Link
Application
Presentation
PDU
Session
Upper Layer Data
Segment
Transport
TCP Header
Upper Layer Data
Network
Packet
IP Header
Data
Purpose: This figure illustrates encapsulation.
Emphasize: The protocol data units (PDUs) are the terms used in the industry and in this course to describe data at the different layers.
Encapuslation is a key concept that illustrates how data is formatted prior to being sent across a link. This example is an illustration is Ethernet (or token ring) at the data link and physical layer and TCP/IP at the network and transport layers.
Transition: The following discusses de-encalsulation.
LLC Header
Data
FCS
Data Link
Frame
MAC Header
Data
FCS
Physical
Bits

21. De-encapsulating Data
Application
Presentation
Session
Upper Layer Data
Transport
Upper Layer Data
TCP Header
Network
TCP+ Upper Layer Data
Purpose: This figure illustrates de-encapsulation.
Emphasize: At the destination, the headers at each layer are stripped off as the data moves back up the stack.
IP Header
IP + TCP + Upper Layer Data
Data Link
LLC Header
LLC Hdr + IP + TCP + Upper Layer Data
MAC Header
Physical

22. Functional Responsibilities
Written Exercise: OSI Model
OSI Model
PDU
Functional Responsibilities
Examples
Application
Presentation
Session
Transport
Purpose: This exercise is intended to re-enforce students understanding of the OSI model.
Note: Students should fill in the empty spaces to complete the table.
Answers are in the “Answers” appendix.
Network
Data Link
Physical

23. Physical Layer Functions
Defines
Media type
Connector type
Signaling type
Ethernet
802.3
EIA/TIA-232
V.35
Physical
Purpose: This section describes the physical layer in more detail.
Note: is responsible for LANs based on the carrier sense multiple access collision detect (CSMA/CD) access methodology. Ethernet is an example of a CSMA/CD network.
EIA/TIA-232 and V.35 are physical standards that support synchronous serial.

24. Physical Layer: Ethernet/802.3
10Base2—Thick Ethernet 10Base5—Thick Ethernet
Host
Emphasize: Network topology is not necessarily connected to network technology. For example, many Ethernet networks have a backbone bus topology. However, adding a switch or a hub to an Ethernet network changes it to a star topology.
IEEE 802.3u defines the standard for a CSMA/CD LAN operating at 100Mbps, Fast Ethernet.
In the case of Ethernet, such as 10BaseT, the first part describes the speed of the cable, the second part describes whether it is baseband or broadband cable, the final part describes the media. So, 10BaseT is 10 Mbps baseband twisted-pair cable.
Hub
10BaseT—Twisted Pair
Hosts

25. Hubs Operate at Physical layerD
Emphasize: All devices attached to a hub are on the same collision and broadcast domain. A hub is a layer one device.
All devices in the same collision domain
All devices in the same broadcast domain
Devices share the same bandwidth

26. Hubs: One Collision Domain
More end stations means more collisions
CSMA/CD is used
Purpose: This figure compares hubs in a CSMA/CD environment to a highway with multiple access points.
Emphasize: The more entrance points onto the highway, the greater the likelihood for a collision to occur. Likewise, the more end stations on a hub trying to access the line, the more collisions occur.

27. Data Link layer Functions
Defines
Physical source and destination addresses
Higher layer protocol (Service Access Point) associated with frame
Network topology
Frame sequencing
Flow control
Connection-oriented or connectionless
802.2
Data Link
Frame Relay
HDLC
Ethernet
Purpose: This figure compares physical standards to data link standards.
Emphasize: As illustrated, certain physical standards are associated with certain data link standards. For example, is used with data link standard for Ethernet. It is not used in WAN connections.
802.3
EIA/TIA-232
v.35
Physical

28. Data Link Layer Functions (cont.)
MAC Layer
# Bytes 8 6 6 2
Variable 4
Preamble
Dest add
Source add
Length
Data
FCS
Ethernet II uses “Type” here and
does not use
Emphasize: All MAC addresses on a LAN must be unique. Two devices with the same MAC address cannot be on the same data link.
Note: The IEEE assigned vendor code is just one of Cisco’s many MAC vendor codes. Cisco has many more, many of which came with Cisco’s acquisitions.
0000.0C xx.xxxx
IEEE assigned
Vendor assigned
MAC Address

29. Data Link Layer Functions (cont.)
802.2 (SNAP) 1 1
1 or 2 3 2
Variable
Dest SAP AA
Source SAP AA
Ctrl 03
OUI ID
Type
Data OR
802.2 (SAP) 1 1
1 or 2
Variable
Note: Different upper layer protocols use either SNAP or SAP.
Dest SAP
Source SAP
Ctrl
Data
Preamble
Dest add
Source add
Length
Data
FCS
MAC Layer

30. Switches and Bridges Operate at Data Link Layer
Emphasize: To reduce the number of collisions, a switch can be split into multiple segments, each in a separate collision domain. Note that all segments are in the same broadcast domain. OR 1 2 3 4 1 2
Each segment has its own collision domain
All segments are in the same broadcast domain

31. Switches Switch Each segment has its own collision domain
Purpose: This figure compares the switch to a highway.
Switch
Memory
Each segment has its own collision domain
Broadcasts are forwarded to all segments

32. Network Layer Functions
Defines logical source and destination addresses associated with a specific protocol
Defines paths through network
Interconnects multiple data links
Network
IP, IPX
802.2
Data Link
HDLC
Frame Relay
Purpose: This figure maps the lower layers to the network layer.
Emphasize: Routing occurs at the network layer. Most of this course uses the IP network layer protocol. It supports multiple lower layer protocols. IPX will also be covered in a single chapter in this course.
Routers are network layer devices.
Ethernet
802.3
EIA/TIA-232
v.35
Physical

33. Network Layer Functions (cont.) Network Layer End Station Packet
Source address
Destination address IP
Header
Data
Logical Address
Emphasize: Route determination occurs at this layer so a packet must include a source and destination address.
Network layer addresses have two components, a network component for internetwork routing and a node number for a device specific address. The example in the figure is an example of an IP packet and address.
Network
Node

34. Network Layer Functions (cont.)
Address
Mask
172 16
122
204
Binary Address
Purpose: This slide gives students enough information about IP addresses until it is covered in-depth in Chapter 8, “Interconnecting Networks with TCP/IP.”
Emphasize: IP address format is dotted-decimal. Dotted-decimal makes it easy to work with IP addresses.
Students should be familiar with binary. In this course we will work with the addresses on the bit level, so we will convert these addresses into binary, make changes to them, and convert them back.
Let students know that the IP address is a 32 bit address. It has a network portion and host portion. The subnet mask is a 32 bit mask that divides the address into the two portions.
Note: Students should understand this format presented so they can successfully perform the laboratory exercises in this course. They will learn about classes of I P addresses later in the course.
255
255
Binary Mask
Network
Host

35. Network Layer Functions (cont.)
1.0
4.0
1.1
4.1
2.1
2.2
1.3
4.3
1.2
4.2 E0 S0 S0 E0
Routing Table
Routing Table
Emphasize: Routers maintain routes in routing tables.
Before any routing can be done an administrator must configure a router with certain key information such as addresses and tell the router how to determine the best route to use. This is different than a switch which is a plug and play device.
NET
INT
Metric
NET
INT
Metric 1 E0 1 S0 1 2 S0 2 S0 4 S0 1 4 E0
Logical addressing allows for hierarchical network
Configuration required
Uses configured information to identify paths to networks

36. Routers: Operate at the Network Layer
Broadcast control
Multicast control
Optimal path determination
Traffic management
Logical addressing
Connects to WAN services .
Emphasize: Routers perform the network layer functions depicted in the figure.

37. Using Routers to Provide Remote Access
Modem or ISDN TA
Telecommuter
Purpose: Routers provide access into the corporate network via WAN connections.
Emphasize: A main office must be able to support multiple types of connections.
Note: The lightning bolt represents a WAN connection. The dotted lines represent DDR connections. The solid bolts can be packet switched or leased lines.
Mobile User
Branch Office
Main Office
Internet

38. Transport Layer Functions
Distinguishes between upper layer applications
Establishes end-to-end connectivity between applications
Defines flow control
Provides reliable or unreliable services for data transfer
Transport
TCP
UDP
SPX
Purpose: This figure describes the transport layer.
Emphasize: Two transport layer protocols in the IP stack are TCP and UDP. TCP will offer more reliability because it is connection oriented. UDP guarantees no reliability.
Sequence Packet Exchange (SPX) is the transport layer protocol used by IPX. It is also connection oriented. Newer versions of IPX support TCP and UDP as well.
Network IP
IPX

39. Reliable Transport Layer Functions Connection Established
Sender
Receiver
Synchronize
Acknowledge, Synchronize
Purpose: This figure illustrates a TCP connection being established.
Emphasize: The exchange is sometimes referred to as the “three-way-handshake.” The initiating host requests a synchronization. The receiver acknowledges the synchronization and specify synchronization parameters in the opposite direction. The receiver acknowledges the synchronization and a connection is established.
Acknowledge
Connection Established
Data Transfer
(Send Segments)

40. Network Device Domains
Hub
Bridge
Switch
Router
Emphasize: This figure summarizes the different collision domains and broadcast domains on various network devices. It is important that students understand the difference between the two domains.
Collision Domains:
Broadcast Domains:

41. Choosing a Cisco Product
Core Layer
Distribution
Layer
Purpose: This figure reintroduces the heirarchical model presented earlier in this chapter. Its intention is to use help explain where in the network different network devices may be placed.
Access
Layer

42. Product Selection Considerations
Provides functionality and features you need today
Capacity and performance
Easy installation and centralized management
Provides network resiliency
Investment protection in existing infrastructure
Migration path for change and growth
Seamless access for mobile users and branch offices
Purpose: The figure highlights some of the many considerations with product selection.

43. Product Selection Considerations (cont.)
First select WAN technology solutions based on the following:
Availability of service
Bandwidth requirement
Cost
Second, choose products that support selected WAN solutions
Emphasize: When selecting a WAN technology, determine how much you will use the connection services and choose a technology based on that usage.
You don’t want to pay for more than what you need, but you do want to make sure you’re prepared for future growth.
Look for software features that support bandwidth optimization techniques such as Dial-on-Demand, Bandwidth-on-Demand, Snapshot Routing, and Traffic Prioritization.
Finally, determining the impact of this remote traffic on your corporate LAN to help you plan for and prevent network congestion at the main site.
Modem/ISDN
Cost per Month
Leased Line, T1
Frame Relay
Usage

44. Product Selection Considerations (cont.)
kbps
1544
128 64 56
19.2
9.6
4.8
Leased Line,
Frame Relay,
XDSL
Video, Multimedia
ISDN, Frame Relay
Voice
Web Browsing
Purpose: This figure maps the services you wish to run to speed and WAN services you may require.
New Modem
, File Transfer
Old Modem
Telnet
Determine applications that you want to run

45. Cisco Hub Products Selection Issues:
Need for 10 Mbps or 100 Mbps on media
Port density
Need for management console
Easy Operations
Cisco FastHub400
Cisco
FastHub300
Cisco
FastHub200
Cisco
FastHub100
Note: The figure of a diagonal with lower end devices to upper end devices will reoccur for switches and routers later in the chapter. Its intent is to illustrate that there are multiple choices for each need rather than mapping a requirement to specific boxes.
Below is some of the information about Cisco’s broad range of shared medium hub products offered during the course development period:
The Cisco 1500 series Micro Hub is a traditional 10 Mbps 8-port hub that is stackable up to 5 devices to provide a total of 40 ports. This tabletop design family comes in both managed and unmanaged models and is ideal for low-cost shared connectivity.
The 1528 Micro Hub provides 8 ports of 10/100 autosensing shared connectivity. An internal bridge function allows all stations to communicate irrespective of connection speed. This hub provides a migration path from 10-Mbps Ethernet to Fast Ethernet.
The FastHub series includes a range of shared Fast Ethernet products that include managed and unmanaged models as well as stackable and expandable models. Their media type includes UTP and fiber. FastHubs are ideal for server farm applications and providing high-performance connectivity for legacy 10BaseT hubs.
Cisco 1528
Micro Hub 10/100
Cisco 1500 Micro Hub

46. Catalyst Switch Products
Selection Issues:
Need for 10 Mbps, 100 Mbps, or 1000 Mbps on media
Need for trunking and inter-switch links
Workgroup segmentation (VLANs)
Port density needs
Different user interfaces
Catalyst series
Catalyst series
Catalyst series
Wiring Closet/Backbone Solutions
Note: The figure of a diagonal with lower end devices to upper end devices will is presented this way to illustrate that there are multiple choices for each need rather than mapping a requirement to specific boxes. For example, desktop solutions are not just 2900XLs. They can also include 1900s and 3000s.
Cisco’s family of Catalyst switches includes standalone switches and modular, flexible chassis systems that offer extensive scalability, multilayer switching, and value-added features that address every aspect of network performance:
For an extremely low price per port, the Catalyst 1900 switches offer an affordable, high-performance alternative or complement to 10BaseT hubs. These switches are for Ethernet workgroups and users requiring increased performance and 100BaseT connectivity to servers and backbones.
The Catalyst 2820 series of Ethernet switches combines high-speed configuration flexibility with exceptional affordability for workgroup applications. These switches are for Ethernet workgroups and individual users requiring increased performance and 100BaseT, FDDI, or ATM connectivity to servers and backbones at a very low cost per port.
The standalone Catalyst 2900 series XL switch provides high-speed configuration flexibility for workgroup applications. The Catalyst 2900 series XL is for Ethernet workgroups and individual users requiring increased performance and 100BaseT or 100BaseF connectivity to servers and backbones.
The Catalyst 3000 series provides a stackable switching architecture that delivers Layer 2 and Layer 3 WAN stackable software and VLAN switching for growing workgroup applications. This family has more switching capacity, a wide range of interface alternatives, and traffic management functions.
Catalyst series
Catalyst 2900 series XL
Catalyst 1900/2820 series
Desktop/Workgroup Solutions
Cisco 1548 Micro Switch 10/100

47. Central Site Solutions Branch Office Solutions Small Office Solutions
Cisco Router Products
Cisco GSR Series
Selection Issues:
Scale of the routing features needed
Port density/variety requirements
Capacity and performance
Common user interface
Cisco 7000 Series
Cisco Series
AS Series
Cisco Series
Cisco Series
Note: The figure of a diagonal with lower end devices to upper end devices will is presented this way to illustrate that there are multiple choices for each need rather than mapping a requirement to specific boxes. For example, home office solutions may range from 700s to 1700s.
Cisco offers a range of router solutions to meet the needs of telecommuters, branch offices, and regional or corporate central sites:
The Cisco 700 series, designed for home office telecommuters, is a low-cost, easy-to-manage, multiprotocol ISDN router. An 800 series router is also offered for small offices. The 800 router is the lowest end router based on IOS software.
The Cisco 1000 series routers are a low priced WAN solution.
The Cisco 1600 series routers, also intended for small remote offices, have a modular slot that accepts a WAN interface card. The 1600 also supports ISDN BRI. The 1700 is similar to the 1600 but includes another WAN interface card slot.
The Cisco 2500 series is designed for branch offices that require more serial ports, more LAN ports, integrated hub ports, integrated T1 DSU/CSUs, and wider protocol support
The Cisco 2600 series extends enterprise-class versatility, integration, and power to branch offices with the Cisco 2600series modular access router family. The Cisco 2600 series shares modular interfaces with the Cisco 1600, 1700, and 3600 series, to meet today's branch office needs.
Central Site Solutions
Cisco Series
Cisco 1600/1700 Series
Branch Office Solutions
Cisco 700/800 Series
Small Office Solutions
Home Office Solutions

48. Visual Objective
Objectives: Using the product selection tool, select the appropriate networking device that meet your requirements.
Purpose: Teach students how to use available Cisco tools to help determine product selection.
Timing: 30 minutes
Equipment Materials: PC equipped with product selection tool loaded.
Laboratory Preparation: Complete this laboratory exercise prior to teaching the course. Try different configurations so you are familiar with the tool prior to teaching the course.
Laboratory Instructions: Load the product selection tool onto each workgroup PC.
Tell students they will get the most up-to-date information if they use the Web based product selection tool. When this book was published the on-line product selection tool could be found at
Tell students that this tool is only intended to help familiarize network administrators with the available options that will help meet their requirements. Additional research is necessary when selecting a product.
Laboratory Review: Multiple choices may available for each requirement.
Use the product selection tool to select Cisco Equipment

49. Summary
After completing this chapter, you should be able to perform the following tasks:
Describe how data moves through a network
Identify the roles and functions of routers, switches and hubs, and specify where each device best fits in the network
Select the appropriate Cisco equipment for a network that combines switching, routing and remote access requirements
Purpose: Review the summary items with your students.
Emphasize: Read or restate the summary statements. By now, your presentation and classroom discussion should have students able to meet the chapter learning objectives.

50. Review Questions
1. What are some of the advantages of using the OSI model in a networking environment?
2. Describe the encapsulation process.
3. How many broadcast and collision domains are on a hub?
Purpose: Review the chapter with open ended questions.
Note: The questions in this section are open ended questions designed to foster further discussion.
Answers the the review questions are in the “Answers” appendix.