Remote Server

Rijosh.vkSsm poly tirurRoll no:19

Topicsl 1..Remote Serverl 2..Accessing Remote serverl 3..File Sharing

A server that is dedicated to handling users that are not on a lan but need remote access to it.The remote access server allows users to gain access to file andprint services on the lan from remote location.

What is Remote Server

l The remote access server allows users to gain access to files and print services on the LAN from a remote location.

l For example, a user who dials into a network from home using an analog modem or an ISDN connection will dial into a remote access server. Once the user is authenticated he can access shared drives and printers as if he were physically connected to the office LAN.

Remote Access

l Remote access is the ability to get access to a computer or a network from a remote distance.In corporations, people at branch offices, telecommuters, and people who are traveling may need access to the corporation's network.

What is Remote Accessl The ability to get accesses to a computer or a

network from a remote distance

l Used for telecommuters accessing to the corporations’ network, home users accessing Internet

l Dial – up connection over regular telephone line is the common method

l Dedicated line between a computer and a remote LAN, is more expensive and less flexible, but is faster

l ISDN combines dial-up connection with a faster data transfer

l Methods of Remote Access

l Dial-up connection through desktop, notebook, or hand held computer modem over regular telephone lines is a common method of remote access

l Remote access is also possible using a dedicated line between a computer or a remote local area network and the "central" or main corporate local area network.

l A dedicated line is more expensive and less flexible but offers faster data rates.

l Integrated Services Digital Network (ISDN) is a common method of remote access from branch offices since it combines dial-up with faster data rates.

l Wireless, cable modem, and Digital Subscriber Line (DSL) technologies offer other possibilities for remote access.

l A remote access server is the computer and associated software that is set up to handle users seeking access to network remotely.

l Sometimes called a communication server, a remote access server usually includes or is associated with a firewall server to ensure security and a router that can forward the remote access request to another part of the corporate network.

l A remote access server may include or work with a modem pool manager so that a small group of modems can be shared among a large number of intermittently present remote access users.

l A remote access server may also be used as part of a virtual private network (VPN).

File Sharing

File sharing is the public or private sharing of computer data or space in a network with various levels of access privilege.

While files can easily be shared outside a network (for example, simply by handing or mailing someone your file on a diskette), the term file sharing almost always means sharing files in a network, even if in a small local area network. File sharing allows a number of people to use the same file or file by some combination of being able to read or view it, write to or modify it, copy it, or print it.

l File servers make files available to other hosts on the network.

l File service clients obtain file systems from file servers

l File service peers are (both) servers and clients.

l Network file sharing employs Remote Procedure Calls (RPC’s).

l Network File Sharingl Network File Systems allow the users files to “migrate” from

workstation to workstation with them.l Network File Systems simplify life for the user, but generally

make system administration more complicated (due to the setup costs).

l In Lab 6 we will setup the Sun Network File System (NFS) services on the lab machines.

l NFS has two components: The server side software, and the client side software. Each component is actually a suite of programs which implement the sockets required to provide network based filesystems.

l NFS is stateless.

l Network File Sharingl Client Side

l biod - client side caching daemonl mount must understand the hostname:directory convention.l Filesystem entries in /etc/[v]fstab tell the client what

filesystems to mount.

l Network File Sharingl AFS

l When you install AFS, the installation procedure creates some new directories:

l /usr/afsws - contains the binaries for the AFS suite: fs, tokens, ptsl /usr/vice - contains the AFS administrative files:

l cache files (/usr/vice/cache)l administrative information about this AFS client

(/usr/vice/etc).l The package software is also installed. Package is a utility for

updating system files upon reboot.

l What is a P2P network?

l All machines are connected as equall Each user is a Peerl Peers can act as both a server and a client

l What does this mean?l Each user can send and receive files from other

usersl To understand the importance, must look at the other ways of transmitting data

l The Old Days

l Server to Clientl Client requests

information from serverl All data must be on

serverl Server uses all its

bandwidth to send datal Must split up bandwidth

for many users

l Benefits of P2P

l Distributedl Data can be distributed across the entire

networkl Bandwidth is distributed across each machine

with the datal Search processing is distributed

l Redundancy within the network

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