Section Titles:
Network Operations | Networking Printing | E-mail
Multivendor Environments |
Client/Server Computing
Network O/S setup
- 2 Major Types of Multitasking
- Preemptive - O/S can take control of the processor without the task's cooperation
- Advantage of preemptive multitasking: CPU activity can be switched from local tasks to a
network task
- Non-preemptive (Cooperative)
- the task itself decides when to give up the processor
- no other program can run until the non-preemptive program gives up the control of the
processor
- A Network O/S
- ties together all the PCs and peripherals in the network
- coordinates the functions of all PCs and peripherals in a network
- provide security for and access to database and peripherals in a network
- Client Software
- redirector
- process of forwarding requests is done by a redirector
- intercepts requests in the PC
- determines if they should be left alone to continue in the local PC's bus or redirected
out to the network to another server
- designator
- a piece of software that manages the assignment of drive letters to both local and
remote network resources or shared drives
- e.g. share drive in other PC, alphabet as a designator, such as G:
- when an association is made between a network resource and a local drive letter (mapping
a drive), the designator takes care of remembering the path to the network resource.
- when users or applications access the drive, the designator substitutes the resource's
network address for the drive letter before the request is sent to the redirector.
- peripherals
- redirectors can send requests to either computers or peripherals (e.g. LPT1: or Com1 can
refer to local OR network printers. Just give these ports a path to the network device.
- Server Software
- makes it possible to SHARE resources (data, printers, modems, etc.) with workstations
- provides network security as well
- makes sure two users don't use the same resources at the same time.
- managing users - create, privileges, remove users
- network management tools to track network behaviour
- The server also
- Provides logon authentication for users
- Manages users and groups
- Stores management, control, and auditing tools for network administration
- Provides fault tolerance for protection of network integrity
- Windows NT Server
- When installing you must
- name the domain or workgroup
- name the server
- the 1st server installed in a domain must be installed as the primary domain controller
(PDC), every domain is required to have one and only one PDC
- a backup domain controller
- keeps a copy of the domain's directory database
- authenticates logons
- can be an application server
- Configuring the network adapter card - default protocol for NT server is TCP/IP
- TCP/IP installation
- IP address
- logical 32-bit address to identity a TCP/IP host
- has two parts: network ID and host ID
- subnet mask - is used to mask a portion of the IP address so that TCP/IP can
distinguish the network ID from the host ID - 255.255.0.0
- default gateway - (gateway = ROUTER) - For communication with a host on
another network, an IP host must be configured with a route to the destination network
otherwise only communication on the local segment
- manual install - assign IP address, subnet mask and the default gateway
- automatic install - DHCP (Dynamic Host Configuration Protocol) service,
- when a DHCP server is configured on the network, clients that support DHCP (NT W/S &
NT Server) can request TCP/IP configuration info (IP address, subnet mask, default gateway
and so forth) from the DHCP server
- Here's the remote printing process:
- the PC's redirector put the print job onto the network cable
- print server's network software takes the print job from the cable and send it into a
queue with other items waiting from access to the shared printer
- UNC syntax: \\print_server_name\printer_share_name
- network uses a spool (simultaneous peripheral operation on line)
- a spooler is a memory buffer in the print server's ram that holds print jobs If there
are too many print jobs to fit into RAM, the overflow wait to print on the print server's
hard drive.
- To share a printer you must:
- load printer drivers so the printer will print correctly
- Create a share name for the printer
- identify a port so the redirector will know where to send the print job
- set the information and output parameters so the network operating system will know how
to handle and format the print job.
- PDL - (Printer Description Language)
- the printer uses the PDL to construct text and graphics to create the page image
- PDLs are like blueprints
- You can manage the printer remotely
X.400 Components
- X.400 defines a whole range of protocols for transferring mail between e-mail servers.
- The Three main components are:
- UA=> user agents
- MTA => Message Transfer Agent
- MTS => Message Transfer System
- E-mail Client (UA, User Agent) responsible for all user interaction such as
- reading and composing messages. It runs on the
- MTA (Message Transfer Agent) responsible for transferring messages from
- one user's mailbox to another or to other MTAs for delivery.
- MTS
- Responsible for transferring messages of all types for the UA that creates the
message to the destination UA
- Directory services Personal Address Book, Global Address List.
X.500
- is a set of directory services developed to help users in distributed networks locate
users on other networks to whom they want to send messages
- Post Office (Information store, Message store) location of all user messages.
E-mail protocols
Transport/Delivery protocols
- POP3 (Post Office Protocol) and IMAP4 (Internet Mail Access Protocol)
- describes how e-mail client interact with email server.
- SMTP (Simple Mail Transport Protocol)
- describes how e-mail servers transfer email message to their intended recipients.
- SMTP works with other e-mail programs to provide both a client and a server the function
to send and receive e-mail messages.
- used on the Internet, UNIX and in the TCP/IP stack
- MIME (Multipurpose Internet Mail Extension)
- defines the method in which files are attached to SMTP messages.
- MHS (Message Handling Service) within NetWare
- similar to X.400 => one computer on the network is the MHS sever and it translates
messages between computers that may be using different e-mail systems
Directory Services
- LDAP (Lightweight Directory Access Protocol)
- X.500 (see above)
Messaging APIs
- MAPI (Message Application Programming Interface)
- MS standard and incorporated throughout all of its office products.
- VIM (Vendor-Independent Messaging) from Lotus
- Scheduling
Groupware
- eg. BBS, Internet news, Interactive conferences, MS Exchange, Lotus Notes.
- Group discussions
- Workflow automation.
- Help Desk
- Collective document creation.
- Internal publishing
Networks in a Multivendor Environments |
- server's O/S, the client's O/S & the redirector have to be compatible
- Different clients have to be able to understand each other to communicate. How can you
get this done?
- the client solution
- implement the appropriate redirector on the client, the redirector forwards your request
to the appropriate destination
- use multiple redirectors to communicate with different clients
- the server solution
- install a service on the service
- E.g. to let MAC clients share network resources, add Service for Macintosh; Add FPNW for
NetWare clients
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