Page 23 - M. Abrahim Thesis

Computer Network 2021

Figure 2-3 shown a MAN Hierarchy

https://www.youtube.com/watch?v=o3wqv1lRnHg

2.4.4 Specialized Networks Located Within the LAN

There are times when smaller and more specialized networks might reside within the
LAN. Most notably, these specialized networks are used for access to storage systems, data
center technology systems and devices, intranets or extranets, and VPNs. These various
specialized networks are covered in this section.

https://www.youtube.com/watch?v=AlkqQUGPDc0

2.4.4.1 Storage-Area Networks (SANs)

A storage-area network (SAN) is a dedicated, high-performance network that moves data
between servers and storage resources. Because it is a separate dedicated network, it avoids
any traffic conflict between clients and servers, as shown in Figure 2-4.
• SAN technology allows high-speed server-to-storage, storage-to-storage, or
serverto-server connectivity. This method uses a separate network infrastructure
that relieves any problems associated with existing network connectivity. SANs offer
the following features:
• Performance—SANs enable concurrent access to disk or tape arrays by two or more
servers at high speeds, providing enhanced system performance.
• Availability—SANs have disaster tolerance built in, because data can be mirrored
using a SAN up to 10 kilometers (km) (6.2 miles) away.
• Scalability—Like a LAN/WAN, a SAN can use a variety of technologies. This allows
easy relocation of backup data operations, file migration, and data replication
between systems.

27