ccna 200 301 blueprint

ccna 200 301 blueprint.Multiprotocol Label Switching (MPLS) follows similar ideas to Frame Relay and Ethernet WANs. However, just like Ethernet WANs, many MPLS WAN service types exist. So to identify and understand the basic concepts, this section explores a specific use of MPLS, namely MPLSVPNOThe MPLSVPN service fits the familiar WAN model of customers connecting sites to an MPLS cloud while the cloud forwards data to all customer sites connected to the cloud. To keep data private, for two unrelated clients A and B, MPLS does not send A's data to B's router, or vice versa.Many facts make MPLS VPNs different from other WAN services, but the biggest difference is that the service is likely to send customer IP packets between sites rather than sending bits (leased lines) or sending data link frames (Frame Relay and Ethernet WANs).O To the customer, the MPLS network is essentially like an IP network that routes customer IP packets between sites.Figure 15-4 illustrates this concept. Customer B connects four routers from B1 to B4 to the MPLS service. Router B3 sends IP packets to the MPLS service (step 1). The MPLS service somehow (details not listed here) sends the IP packets to the other end of the MPLS service. The service then sends the IP packets out the access link to reach the correct client router, B4 in this example (step 3).MPLS is more flexible than other WAN services, which is an added bonus to forwarding IP packets. MPLS supports almost all types of access links that can perform IP packet transport, as shown in Figure 15-4. In fact, although Frame Relay has become less popular in this century, it can still be found in many networks as an access link into MPLS services, as shown in Figure 15-4.Of the WAN services discussed so far in this chapter, MPLS is most similar to Frame Relay and Ethernet WANs. Table 15-4 compares the three mainDifferent points.Figure 15-4 MPLSWAN (MPLS VPN) Service for Sending IP Packets Table 15-4 Key Comparison Points for Ethernet WAN, Frame Relay, and MPLSMPLS Frame Relay Frame Relay Ethernet WANPhysical access link Any IP-enabled device TDM (Tl, El, etc.) Ethernet (fiber)