Chapter 3 – Frame-Relay CCNA pps

1 Chapter 3 – Frame-Relay CCNA Exploration 4.0 Học viện mạng Bach Khoa - Website: www.bkacad.com 2 Introduction Học viện mạng Bach Khoa - Website: www.bkacad.com 3 Basic Frame Relay Concepts Học viện mạng Bach Khoa - Website: www.bkacad.com 4 Introducing Frame Relay Frame Relay: An Efficient and Flexible WAN Technology • Frame Relay has become the most widely used WAN technology in the world. Large enterprises, governments, ISPs, and small businesses use Frame Relay, primarily because of its price and flexibility. • Moreover, Frame Relay provides greater bandwidth, reliability, and resiliency than private or leased lines • Frame Relay reduces network costs by using less equipment, less complexity, and an easier implementation. Học viện mạng Bach Khoa - Website: www.bkacad.com 5 Introducing Frame Relay • In the example shown in the figure, Span Engineering has five campuses across North America. • The bandwidth requirement of each site: Học viện mạng Bach Khoa - Website: www.bkacad.com 6 Introducing Frame Relay The first Solution – Leased line • Using leased lines, each Span site is connected through a switch at the local telephone company's central office (CO) through the local loop, and then across the entire network. • These lines are truly dedicated in that the network provider reserves that line for Span's own use. There is no sharing, and Span is paying for the end-to-end circuit regardless of how much bandwidth it uses. Học viện mạng Bach Khoa - Website: www.bkacad.com 7 Introducing Frame Relay The second Solution – Frame Relay • Frame Relay is a more cost-effective option for two reasons. – First, with dedicated lines, customers pay for an end-to-end connection. That includes the local loop and the network link. • With Frame Relay, customers only pay for the local loop, and for the bandwidth they purchase from the network provider. – The second reason for Frame Relay's cost effectiveness is that it shares bandwidth across a larger base of customers. Học viện mạng Bach Khoa - Website: www.bkacad.com 8 Introducing Frame Relay • The table shows a representative cost comparison for comparable ISDN and Frame Relay connections. Học viện mạng Bach Khoa - Website: www.bkacad.com 9 Introducing Frame Relay • The Flexibility of Frame Relay – A virtual circuit provides considerable flexibility in network design. – In Frame Relay, the end of each connection has a number to identify it called a Data Link Connection Identifier (DLCI). – Any station can connect with any other simply by stating the address of that station and DLCI number of the line it needs to use. Học viện mạng Bach Khoa - Website: www.bkacad.com 10 Introducing Frame Relay The Frame Relay WAN • In the late 1970s and into the early 1990s, the WAN technology joining the end sites was typically using the X.25 protocol. However, X.25 have much overhead to the protocol. • Frame Relay has lower overhead than X.25 because it has fewer capabilities. For example, Frame Relay does not provide error correction, modern WAN facilities offer more reliable connection services and a higher degree of reliability than older facilities. [...]... Website: www.bkacad.com 30 Local Management Interface (LMI) Học viện mạng Bach Khoa - Website: www.bkacad.com 31 Using LMI and Inverse ARP to Map Addresses Học viện mạng Bach Khoa - Website: www.bkacad.com 32 Frame Relay Address Mapping • Activity 3. 1.5.5 Học viện mạng Bach Khoa - Website: www.bkacad.com 33 Configuring Frame Relay Học viện mạng Bach Khoa - Website: www.bkacad.com 34 Frame Relay Configuration... create a PVC DLCIs have local significance, although there some implementations that use global DLCIs DLCIs 0 to 15 and 1008 to 10 23 are reserved for special purposes Service providers assign DLCIs in the range of 16 to 1007 – DLCI 1019 - 1022: Multicasts – DLCI 10 23: Cisco LMI – DLCI 0: ANSI LMI Học viện mạng Bach Khoa - Website: www.bkacad.com 21 Frame Relay Address Mapping • Cisco routers support all... is a signaling standard between the DTE and the Frame Relay switch LMI is responsible for managing the connection and maintaining the status between devices LMI Extensions: – VC status messages – Multicasting – Global addressing – Simple flow control Học viện mạng Bach Khoa - Website: www.bkacad.com 28 Local Management Interface (LMI) • • • LMI virtual circuit status messages provide communication and... Tasks Học viện mạng Bach Khoa - Website: www.bkacad.com 35 Enable Frame Relay Encapsulation • • • • Step 1 Setting the IP Address on the Interface Step 2 Configuring Encapsulation R(config-if)# encapsulation frame-relay [cisco | ietf] Step 3 Setting the Bandwidth Step 4 Setting the LMI Type (optional) Học viện mạng Bach Khoa - Website: www.bkacad.com 36 ... station for its Layer 3 address At the same time, it provides the remote system with the Layer 3 address of the local system The return information from the Inverse ARP is then used to build the Frame Relay map Học viện mạng Bach Khoa - Website: www.bkacad.com 24 Inverse ARP • Inverse Address Resolution Protocol (Inverse ARP) was developed to provide a mechanism for dynamic DLCI to Layer 3 address maps •... circuits are virtual because there is no direct electrical connection from end to end There are 2 ways to establish VCs: – SVCs, switched virtual circuits, are established dynamically by sending signaling messages to the network (CALL SETUP, DATA TRANSFER, IDLE, CALL TERMINATION) – PVCs, permanent virtual circuits, are preconfigured by the carrier, and after they are set up, only operate in DATA TRANSFER... much the same way Address Resolution Protocol (ARP) works on a LAN • However, with ARP, the device knows the Layer 3 IP address and needs to know the remote data link MAC address • With Inverse ARP, the router knows the Layer 2 address which is the DLCI, but needs to know the remote Layer 3 IP address Học viện mạng Bach Khoa - Website: www.bkacad.com 25 Inverse ARP • On a Cisco router, Inverse ARP is... Inverse ARP only resolves network addresses of remote Frame-Relay connections that are directly connected Inverse ARP does not work with Hub-and-Spoke connections When using dynamic address mapping, Inverse ARP requests a next-hop protocol address for each active PVC Once the requesting router receives an Inverse ARP response, it updates its DLCI-to-Layer 3 address mapping table Dynamic address mapping is... Relay WAN Học viện mạng Bach Khoa - Website: www.bkacad.com 13 Virtual Circuits Idenfiying VCs • Frame Relay labels each VC with a DLCI • The DLCI is stored in the address field of every frame transmitted to tell the network how the frame should be routed • The Frame Relay service provider assigns DLCI numbers Usually, DLCIs 0 to 15 and 1008 to 10 23 are reserved for special purposes Therefore, service providers... Operation • The connection between a DTE device and a DCE device consists of both a physical layer component and a link layer component: – The physical component defines the mechanical, electrical, functional, and procedural specifications for the connection between the devices – The link layer component defines the protocol that establishes the connection between the DTE device, such as a router, and the . 1 Chapter 3 – Frame-Relay CCNA Exploration 4.0 Học viện mạng Bach Khoa - Website: www.bkacad.com 2 Introduction Học viện mạng Bach Khoa - Website: www.bkacad.com 3 Basic Frame Relay. www.bkacad.com 7 Introducing Frame Relay The second Solution – Frame Relay • Frame Relay is a more cost-effective option for two reasons. – First, with dedicated lines, customers pay for an end-to-end. 9 Introducing Frame Relay • The Flexibility of Frame Relay – A virtual circuit provides considerable flexibility in network design. – In Frame Relay, the end of each connection has a number to