PeertoPeer vs ClientServer Network Operating Systems Instructor Dr

Peer-to-Peer vs. Client/Server Network Operating Systems Instructor: Dr. Najla Al-Nabhan 2015 1

Peer-to-peer vs. server-based networks A network is either: a peer-to-peer network (also called a workgroup) or a server-based network (also called a client/server network). Peer-to-peer based NW 2 Client/Server based NW

Peer-to-peer networks In a peer-to-peer network, a group of computers is connected together so that users can share resources and information. In most peer-to-peer networks, it is difficult for users to track where information is located because data is generally stored on multiple computers. This makes it difficult to back up critical business information, and it often results in small businesses not completing backups. Often, there are multiple versions of the same file 3 on different computers in the workgroup.

Peer-to-peer networks In some peer-to-peer networks, the small business uses one computer that is running a client operating system, such as Microsoft Windows 98 or Windows XP Professional, as the designated "server" for the network. Although this helps with saving data in a central location, it does not provide a robust solution for many of the needs of a 4 small business, such as collaborating on

Client/Server Networks In a server-based network, the server is the central location where users share and access network resources. This server controls the level of access that users have to shared resources. Shared resources are in one location, making it easy to back up critical business information. Each computer that connects to the network is called a client computer. 5

Client/Server Networks In a server-based network, users have one user account and password to log on to the server and to access shared resources. Server operating systems are designed to handle the load when multiple client computers access server-based resources. 6

Client/Server Networks A Server OS is installed and configured as the central server on a server-based network mainly to provide: 1. the central point for authenticating users, 2. accessing resources, and 3. storing information. 7

Peer-to-peer NOS Computers in peer-to-peer networks are usually equipped with a desktop operating system in order to allow them to create and share resources with each other. All computers are considered equal because they have the same capabilities including : routing and management functions. Two well-known NOS : 8 Windows for workgroup/windows 95 Appleshre

Peer-to-peer NOS The range of features offered by peer-topeer NOS is limited when compared to server NOS. They usually offer file sharing and printing as basic features For small networks 9

Peer-to-peer NOS: Advantages and disadvantages 10

Windows for Workgroups/Windows 95 Windows for Workgroups, introduced in the early 90 s Windows 95, introduced in 1995 They are both considered peer-to-peer networking systems and do not have the capabilities of true internetworking operating systems. They are, however, inexpensive and more than adequate for small workgroups wanting to share resources, use email, and connect to the Internet. 11

Windows for Workgroups/Windows 95 Windows for Workgroups and Windows 95 both offer peer-to-peer network protocols. The protocols used by these operating systems allow users to share files and devices over LANs. Both offer Net. BEUI (Microsoft’s small network protocol). They also offer TCP/IP, and IPX/SPX protocols to access the network through either a dialup connection/modem, or 12 directly through a NIC.

Net. BEUI features Pronounced net-booey, Net. BEUI is short for Net. Bios Extended User Interface. It is an enhanced version of the Net. BIOS protocol used by network operating systems such as: LAN Manager, LAN Server, Windows for Workgroups, Windows 95 and Windows NT. Netbeui was originally designed by IBM for their Lan Manager server and later extended by Microsoft and Novell. 13

Net. BEUI features Net. BEUI protocols, are : not routable, more than adequate to meet small LAN needs. easy to use and do not require in-depth networking knowledge. Net. BEUI software identifies computer devices by name it is easier to remember that a computer name is Nora than 141. 252. 20. 2 or 141. 252. 10. 1. 14

Windows for Workgroups/Windows 95 Each device name in a network must be unique. Net. BEUI software installed on each of the networked computers is all that is necessary to configure devices in order to share resources and create a network. If a small company does want to connect to the Internet, the necessary software and protocols are available with these operating systems. Shared resources on Windows for Workgroups/95 networks are accessed by a password that protects the resource and there is only one level of access; either you have access or you don’t have access. 15

Windows for Workgroups/Windows 95: Security Issues Also user-by-user passwords are not part of the protocols unless Windows NT is present. What this means is that anyone connected to the network who knows the password of the resource has access to that resource. This can create security issues since there is no way to prevent a user from access once s/he knows the password. 16

Windows for Workgroups/Windows 95: Security Issues As the network grows, it is usually more difficult to keep resource passwords secure. Since there is no central control, managing these peer-to-peer networks becomes an issue when the network becomes too large. 17

Windows for Workgroups/Windows 95: Security Issues To be continued next lecture… 18