Ch 10: Wide Area Networking and Cloud Computing
500 GB of space without worrying about how that space is actually provided. In addition, if a
46. What is multiplexing, and where is it used?
Multiplexing allows for multiple communication streams to travel over the same cable
segment simultaneously. T-carrier lines make extensive use of multiplexing to achieve their
speeds, but they require a CSU/DSU at the end of each link for the multiplexing process.
47. What is an Ethernet WAN and what are its strong points?
Many service providers offer Ethernet WANs over fiber-optic cabling. Two of the common
names for this technology are Metropolitan Ethernet (Metro Ethernet or just MetroE) and
Ethernet over MPLS (EoMPLS). Because most LAN infrastructures are based on Ethernet,
Ethernet WANs allow for reduced administration and easier integration of the WAN into the
LAN. A typical Ethernet WAN link can operate at 1 GBps and range in distance from 5 km
to over 70 km.
48. Why would you want to deploy a WAN over the Internet?
Using VPN connections over inexpensive Internet connections is a popular WAN alternative.
VPN connections can be used for secure communication from branch offices to the main
office. VPNs offer some advantages over other WAN methods: inexpensive, convenience,
security, and flexibility.
49. Describe how a company can use IaaS and how it might be a benefit to that company.
Infrastructure as a service (IaaS) allows companies to use a vendor’s storage or even entire
virtual servers as needed. Traditionally, if a company needed more storage to house a new
database, it had to buy a new hard drive. By using IaaS, the company simply pays for another