Server Application Software

1
Server Application Software

• File Service Allows File Sharing
• File server stores program and data files
• Can be accessed by any user with access rights
• Built into most SOSs

Access Rights
File Server
No Access Rights
2
Server Application Software

• File Service
• For sharing application program files also
• No need to install applications on each PC
• Greatly reduces installation labor

File Server
3
Server Application Software

• File Server Program Access
• Program is STORED on the file server

File Server
4
Server Application Software

• File Server Program Access
• But program is EXECUTED on the client PC
• Limited by power of client PCs, which do not get
  very large

File Server
5
Server Application Software

• Typical Application Software
• Word processing, e-mail, etc.
• Must buy multiuser versions, not just a single
  copy from a retail store
• License will limit the number of users
• Will cost more than the SOS

6
Server Application Software

• Print Service
• Also built into SOSs
• Print jobs go to shared printers
• But they first go to the file server
• Not directly to the print server!

Print Server
File Server
Shared Printer
Client PC
7
Server Application Software

• Print Service
• File server stores print job in a print queue
  until print server is ready to print it
• File server sends the print job to the print
  server

Print Server
File Server
Shared Printer
8
Server Application Software

• Print Server
• Print server feeds the print job to the printer
• Print servers are simple and inexpensive because
  the file server does most of the work
• Low print server cost allows shared printers can
  be scattered throughout the office

Print Server
File Server
9
Server Application Software

• Print Server
• Connects to printer via parallel port on the
  print server no special printer needed
• Has NIC to connect to the hub or switch
• Requires an RJ-45 port on the hub or switch

Print Server
RJ-45 Port
UTP
Parallel Cable
10
Server Application Software

• Print Server Location
• Parallel cable distance limitation requires print
  server to be within 1-2 meters of the printer
• UTP allows print server to be up to 100 meters
  from the hub or switch

Print Server
RJ-45 Port
UTP (up to 100 m)
Parallel Cable (1-2 m only)
11
Server Application Software

• Remote Access Service (RAS)
• User dials into a remote access server
• Server authenticates the user (user must prove
  identity)
• If authenticated, user may use internal services
• Client PC needs RAS software

RAS Client Software
RAS
Internal Server
Dial-Up Telephone Line
LAN
Dial-In Client
12
Server Application Software

• Internet Access for a Simple PC LAN
• Serial Router
• Simple, inexpensive router
• One RJ-45 port for LAN, one suitable port for ISP
  Connection

Access Line
Serial Router
13
Server Application Software

• Serial Routers
• May provide security to stop outside hackers
• Network address translation (NAT) hides addresses
  of internal machines
• Only serial routers IP address appears in
  outgoing packets

Serial Router
Access Line
IP Packet with Serial Routers IP Address
14
Server Application Software

• Serial Routers
• Provide security to stop outside hackers
• May provide a firewall (discussed in Chapter 10)
  to prevent unauthorized access from Internet
  hackers

Serial Router
Access Line
15
Server Application Software

• Directory Servers
• Problem Most networks have many servers
• To use a resource, must know the server
• To send e-mail, address is user_at_server
• Files must be accessed on particular servers

16
Server Application Software

• Directory Servers
• Directory server knows all resources on all
  servers
• Can send mail to user (without _at_server)
• Can search for a specific file across servers

Directory Server
17
Server Application Software

• Directory Servers
• Know user access rights on all servers
• Single login to directory server
• Get access to all other servers where user has
  access rights

Directory Server
Single Login