Server Application Software

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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

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

Server Application Software

File Server Program Access

– Program is STORED on the file server

File

Server

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

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

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

Client PC

File Server

Shared

Printer

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

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

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

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

RJ-45 Port Print Server

UTP (up to 100 m)

Parallel Cable

(1-2 m only)

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

Internal

Server

RAS

RAS

Client

Software

LAN

Dial-Up

Telephone

Line

Dial-In

Client

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

Server Application Software

• Serial Routers

– May provide security to stop outside hackers

• Network address translation (NAT) hides addresses of internal machines

• Only serial router’s IP address appears in outgoing packets

Serial Router Access

Line

IP Packet with Serial

Router’s IP Address

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

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@server

• Files must be accessed on particular servers

Server Application Software

• Directory Servers

– Directory server knows all resources on all servers

– Can send mail to user (without @server)

– Can search for a specific file across servers

Directory

Server

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

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