Question

Consider the Textbook Management Focus 9-4 below. What other alternatives do you think Cisco considered for their wide area networks (WANs)? Why do you think they did what they did?

For years, Cisco Systems Inc. had supported its Europe/Middle East/Africa (EMEA) offices with a series of star networks connected to stars (called a hub-and-spoke design). The WAN core was three offices (London, Amsterdam, and Brussels) connected to each other in a full mesh using OC-3 circuits. Each of these three offices was the center of a star network that connected to three other secondary star networks and 10 major sites (9 stars and 30 major sites in total). The nine secondary stars connected a total of 85 other offices. The network was at capacity, and any time one of the three core offices (or one of the hubs of the secondary stars) needed to be taken down for maintenance, it shut down a major part of the network. Worse still, it looked like the London office would need to move to a new building, which meant significant rewiring of the network. Cisco chose to implement a full mesh [Multiprotocol Label Switching] MPLS network to provide greater capacity and better flexibility. Each office is connected into the MPLS carrier’s cloud with two separate MPLS circuits that are laid in physically separate routes to provide better reliability in case a circuit is accidentally cut. Each of the two circuits is sized for the needs of the specific office, ranging from 64 Kbps up to 45Mbps. Since the three core offices no longer route traffic for the entire network, they don’t need as much network capacity as they did with the hub and spoke design. The new network has significantly increased capacity, reliability, and flexibility, while keeping costs about the same.

Answer 1

Question 1

The other alternatives Cisco considered for their wide area networks (WANs) are as follows
a.SD-WAN Edge  
b.Cloud-based SD-WAN
c.VPN

Question 2

The reason Cisco choose the current scenario because

a.It has a lower cost as it is a layer 2.5 technology
b.Scalability
c.MPLS has a built in support for Quality of service.
d.MPLS can do outsourced routing.