Group15_krazzy4:comparision of remote login tools

	LOGMEIN	TEAMVIEWER	PUTTY	RDM+
REMOTE USER	Computer	computer	computer	Java mobile mobile
REQUIREMENT	Host computer must be added to the remote user  +internet +desktop sharing software	TeamViewer must be run in both host computer and remote user + internet + desktop sharing software	Putty must be run on the remote user’s computer. Host and remote should be connected to  internet.	RDM+desktop  must be installed in host computer  and registered and RDm+client in mobile +wi-fi network
WORKING ENVIRONMENT	Windows	Windows	Windows to linux	Windows
FILE TRANSFER	Allows copying of files and folders from and to the remote user	Allows copy the files and folders from and to the remote user	Allows copying of files and folder from and to the remote user	Allows copy the files and folders in the file management mode
WORKS BEHIND FIREWALL	Yes	Yes	Yes	Yes
REMOTE DESKTOP PROTOCOL	Proprietary remote desktop protocol that is transmitted via TLS	SSL(Secure Socket Layer) Protocol	SSH(SECURE SHELL) telnet,rlogin and raw TCP computing	TCP/IP AND HTTP Protocol
CONNECTING REMOTE DESKTOP AND THE REMOTE USER	Connects using the TLS over TCP utilizing NAT traversal	TeamViewer allows a VPN (Virtual Private Network) connection to be established between remote desktop and remote user	Using tunnels with SSH is a powerful method to access services on systems behind a firewall or that are otherwise inaccessible.	Direct TCP/IP,BES/MDS,BIS transport option
SECURITY	A TLS certificate is used to cryptographically secure communucation	TeamViewer uses a full encryption, based on RSA private-/public key exchange and AES (256 Bit) session encoding	SSH provides an encrypted communication between two hosts over an insecure network and thus prevents user’s pwd .	Wipe user information option clears all user data in RDM+ client
NEED FOR A SESSION	Go to the LogMeIn Express site and type in the session code which is obtained when client application is running	Partner ID and password.	Partner’s IP address and administrator password	The computer number and the account which you specified during the installation of the desktop part in the computer list of the RDM+ client.
FOUNDED	The technology behind LogMeIn was developed as the RemotelyAnywhere product in Budapest, Hungary by 3am Labs BT and opened an office in Woburn, MA	TeamViewer  was founded in 2005 in Uhingen, Germany	———————-	———

Group15_krazzy4:Question & Answer over REMOTE LOGIN

Q1) Why is Team viewer not affected by any firewall?

(by MURGESH KALYANI)

A1) Essentially Team viewer uses port 80 for remote login. It is the default port for http traffic. This port is not affected by any firewall hence team viewer can circumvent firewalls.

(by AAYUSH KEJRIWAL)

Q2) How SSH is secured? (by NEHA SHARMA)

A2) SSH provides an encrypted communication between two hosts over an insecure network and thus prevents user’s password and other sensitive data from being transmitted across network in a clear text form.

(by HIMANSHU MOUAR)

Q.3)What is ssh? (by Vikram Singh)

A4) Secure Shell or SSH is a network protocol that allows data to be exchanged using a secure channel between two networked devices. Used primarily on Linux and Unix based systems to access shell account, SSH was designed as a replacement for Telnet and other insecure  remote shells, which send information, notably passwords, in plaintext, leaving them open for interception. The encryption used by SSH provides confidentiality and integrity of data over an insecure network, such as the Internet.

(by Vinayak thakur)

4.)Uses of SSH?

A5)SSH is a protocol that can be used for many applications. Some of the applications below may require features that are only available or compatible with specific SSH clients or servers. For example, using the SSH protocol to implement a VPN is possible, but presently only with the Open SSH server and client implementation.                                  (by Royston Menezes)

Q5)What is the difference between SSH1 and SSH2?

(by  SHRIDEVI Y.V.)

A3) SSH1 and SSH2 encrypt at different parts of the packets. And SSH1 uses server and host key to authenticate the system; Where as SSH2 only uses host keys. It is complete rewrite of the protocol, and it does not use the same networking implementation that SSH1 does. Also SSH2 is more secure.

(by HIMANSHU MOUAR)

Group15_Krazzy4:Mandatory Blog

Team Name: Krazzy4
Team Members: Aayush Kejriwal(1MS07IS0001), Himanshu Kumar Mouar(1MS07IS032), Royston Menezes(1MS07IS051), Vinayak Thakur(1MS07IS134)
Group A Project Chosen: Remote Login
Group B Project Chosen: Stop and wait ARQ
Presentation Date of Group A Project (Completed / Not Completed as on Blog Date): Completed (On 23rd september,2009).
Presentation Date of Group B Project (Completed / Not Completed as on Blog Date): Completed. (On 11th November,2009)
Group A PPT Uploaded(Yes or No): Yes
Group B PPT Uploaded(Yes or No): Yes
Group A Project Report Made(Yes or No): Yes
Group B Project Report Made(Yes or No): Yes
Group A Project PROBLEMS FACED and SOLVED Blog Uploaded(Yes or No): Yes
Group B Project PROBLEMS FACED and SOLVED Blog Uploaded(Yes or No): Yes

Group_15:Remote Login Problems faced

Some of the problems faced while preparing for our group A projects are:

1. While installing vnc viewer in ubuntu through synaptic packet manager was a tough job as we all were not very use to it.

2. The demonstration on  remote login from a windows environment to an open source environment worked only when there is a facility of internet connection , since there was problem in connection in the lab it created problems but thanks to ankan and harsh for helping us out with their router.

Group15_Krazzy4:Algorithm for stop and wait ARQ

Algorithm for stop and wait ARQ

Sender-site algorithm for stop and wait ARQ

Sn=0;                                                                                 //Frame  0 should be sent first

cansend=true;                                                               //allow first request to go

while(true)                                                                     //repeat forever

{

waitforevent();                                                           //sleep until an event occurs

if(event(request to send) AND cansend)

{

GetData();

MakeFrame(Sn);                                                        //The seqno is Sn

StoreFrame(Sn);                                                       //keep copy

startTimer();

Sn=Sn+1;

cansend=false;

}

Waitforevent();                                                            //sleep

if(event(Arrivalnotification))                               //an ACK has arrived

{

receiveFrame(ackno);                                            //receive the ACK frame

if(not corrupted AND ackno==Sn)                   //valid ACK

{

stopTimer();

PurgeFrame(Sn-1);                                               //copy is not needed

cansend=true;

}

}

if(event(timeout))                                             //The timer has expired

{

StartTimer();

ResendFrame(Sn-1);                                         //resend a copy check

}

}

Receiver-site algorithm for stop-wait-ARQ protocol

Rn=0;                                                                       //frame 0 is expected to arrive first

while(true)

{

waitForEvent();                                                //sleep until an event occurs

if(Event(ArrivalNotification))                   //data frame arrives

{

ReceiveFrame();

if(corrupted(frame));

sleep();

if(seqno==Rn)                                                 //valid data frame

{

ExtractData();

DeleiverData();                                              //deleiver data

Rn=Rn+1;

}

SendFrame(Rn);                                          //send an ACK

}

}

Group15_Krazzy4:How Teleconferencig Works

In the past few years, corporations have gotten bigger and more spread out. Many American employees — more than 44 million in 2004 — also do at least some of their work from home . Since offices and employees can be thousands of miles apart, getting everyone into the same room for meetings and training has become decidedly impractical for a lot of companies.

That’s why teleconferencing — the real-time exchange of information between people who are not in the same physical space — has become such a big industry. The American audio conferencing industry alone reported $2.25 billion in revenue in 2004 . Through teleconferencing, companies can conduct meetings, customer briefs, training, demonstrations and workshops by phone or online instead of in person.

In this article, we’ll look at different types of teleconferencing, from conference calls to online meetings

The simplest phone teleconference is a three-way call, available in many homes as a service from the telephone company. Another very simple (but not necessarily effective) method is to have two groups of people talk to one another via speakerphone. The limits of three-way calling and the sound quality of speakerphones make both of these options impractical for most businesses.

Conference calls let groups of people — from a few to hundreds — communicate by phone. Banks and brokerages often use conference calls to give status reports to large numbers of listeners. Other businesses use conference calls to help coworkers communicate, plan and brainstorm. To connect to the call, attendees call a designated number (MeetMe conferencing), or an operator or moderator calls each participant (ad hoc conferencing).

Conference calls connect people through a conference bridge, which is essentially a server that acts like a telephone and can answer multiple calls simultaneously. Software plays a large role in the bridge’s capabilities beyond simply connecting multiple callers.

Group15_krazzy4:CROSSLOOP as Remote login tool

Screen-Sharing and Remote-Collaboration tools:-

1 . CrossLoop – secure, easy-to-setup, screen-sharing application for your Windows desktop.

Features:-
• Share your screen sessions with others.

• Share/Collaborate on running programs (Word, Excel, Powerpoint, etc) with friends or colleagues.

• File transfer and sharing.

• Available in more than 20 languages.

2. TeamViewer – slightly more complicated than Crossloop (not for dummies) but provides more or less same capabilities. Remote desktop sharing, collaboration, file transfer, chat, etc. You (the sharer) can decide whether you want to share the desktop or just allow the file transfer.

Features:-

• Remote desktop sharing, file transfer, chat, etc.

• All data sharing is encrypted and secure.

• Works through Firewalls. No user configurations required.

• You (the sharer) can decide whether you want to share the desktop or just allow the file transfer.

• Completely free for non-commercial use.

• Works only on Windows computers (incl. Vista).

Group15_Krazzy4:HOW TO DESIGN A NETWORK SERVER

Here you will learn designing a network server techniques, windows 2000, memory, processor, power supply, clustering, monitoring, software and hardware requirements of a server.

A computer network server can be configured reliable and efficient according to the needs of a business. If the business is of a critical nature like banks, consulates, police department or corporate companies, the cost on the reliability of the server increases. There are a large number of the objects involved in a computer network such as hubs, routers, Gateway, bridges, ISDN adapters, Modems, transceivers, firewalls and many others and all these devices by some means depends on the server to share data and resources. There are a number of the subsystems involved in the reliability of a server. Following are the tips and recommendations in making a secure, high performance server according to your business needs.

1. Hard Disk Subsystem Reliability

The main server component that is prone to failure is the hard disk that stores the data of the server. Hard disk is a mechanical component in a server. While selecting the disk drives, you should consider the S.M.A.R.T technology (Self monitoring and Reporting technology). This technology allows the monitoring of the disk drives parameters and is able to predict the failure of the disk drives. Most server vendors provide the hot swap disk drives this means that they can be replaced while the server is in working mode. To provide fault tolerance, implement RAID (redundant array of the inexpensive disks). RAID is implemented by installing RAID disk controller in the server. RAID 5 provides fault tolerance by adding the parity information of the data as it is written on the disk drives. This parity information can be used to regenerate the data in case of disk failure. Minimum 3 disk drives are required to implement a RAID 5 (striped set with parity) and the maximum numbers of the disks involved in the RAID5 are 32.

2. Server Processor

Most of the servers use the Pentium processors that are very reliable in performance and processing speed. Processor or CPU is a heart of any server and if it fails to work, the server becomes non functional. Trend is growing to use a dual-processor server or even multiple processor servers. If this scenario, if one processor fails to work, there is not effect on the other processors in a server. So it is a best decision of the network administrators to use the multiprocessor server.

3. Network Subsystem

The attachment of the server to the network is carried out by the NIC adapter. If a NIC of the server fails to work, the connection of the server with the other computers in a network also fails. Many servers support redundant NICs that can be implemented in the fail over or load balancing situations. In the NIC fail over situations one NIC is used to communicate with the server and the other NIC is held reserve until the other NIC fails and the second NIC is automatically activated. In the NIC load balancing situation both the NICs are activated so improve the reliability and performance of the server communication. A PCI hot swap slot allows replacing the faulty NIC adapter without shutting down the server.

4. Clustering

Redundancy is achieved by clustering. In a clustered environment, two or more server operates as a single server and the failure of the one server, does not affect the working of the other server. There are many advantages of the clustered environment such as reliability, load balancing and high performance of the computing environment.

5. Memory Performance

The memory technology has been improved and it fails to work very seldom. Purchasing a memory for a server that supports ECC (Error correcting code) is a best decision of the system ornetwork administrators. ECC technology is capable of detecting and fixing the single bit error and reporting the multiple bit memory errors. A server needs a high amount of memory to perform its function smoothly. If a memory is low in a server, it can results in slow boot up, slow response time and halting the system so memory is a vital for a computing server.

6. Power Supply Usage

Many computers come with the multiple power supplies and these multiple power supplies 2 or more share the electric load of the computer server. The main advantage of the multiple power supplies is that the failure of the one power supply does not cause the server to shut down because other power supply takes all the electric loads and so server works normally without any problem. Like the other hot swappable hardware in the server, the multiple power supply system is also hot swappable. This means the faulty power supply can be replaced with the new one, while the server is running.

7. UPS ( Uninterruptible Power Supply) Function

A UPS or uninterruptible power supply system plays very vital role in case of the power failure. UPS normally provides power back for 3-4 hours and during this time, server can easily be setup to save the data and all the network users can also access the store their important data on the server. The shutdown process of the server is controlled by software that is installed on the server. UPS is very important in a network environment and if there are a number of the UPS in a network, they can share the load and provide constant power supply to the server.

8. Emergency Generator Working

When a full time operation of the server is required such as hosting servers, web servers, email servers, data server, and emergency generator is a necessary. The emergency generators are usually diesel powers and are developed by a number of the world’s renowned companies like Jubaili Brothers, Cummins. These emergency power generators can be set to automatically switch on in case of power failure or they can be used after the UPS is fully used.

9. Cooling Fans Function

There is a large amount of the hardware installed in inside the CPU so there must be cooling system inside the CPU. The cooling of the server is achieved by the cooling fans, which are installed inside the CPU. These cooling fans pull the cool air inside the CPU and throw away the heated air from inside the CPU. The failure of the cooling fans in the server leads to the automatic shut down of the server due to high buildup heat in the server. Many vendors are providing the hot swappable cooling fans.

10. Computer Monitoring Hardware

There is a specially designed adaptor available for monitoring the performance of the different components of the server. The server can be monitored locally or remotely via a modem by this adapter. In very critical network environments, these types of adapters are usually used in the server to put a check on the performance of the different networking devices.

11. Computer Server Software

Software installed on the server should be very reliable and virus free. A good anti virus software like Norton Anti Virus, Trend Micro, McAfee Anti virus, Panda Anti virus or any other anti virus should be installed and updated. Additionally, a good firewall, anti spyware, malware, adware should also be installed to keep the server virus or spyware free. Good backup software should also be installed on the server in case of any emergency. Any unwanted software, media players, codec, flash games or emails can provide a room for the viruses from the internet to enter in your network. No unauthorized software applications or hardware should be installed in the server. If a virus enters in the server by any means, it is very easy for the viruses to spread all over the network and if they are of severe nature, they can even destroy all your critical data. The above mentioned recommendations for a designing a good server can play a key role in designing a secure, reliable and high performing server for your computer network.

12. Data Server Location

A server should be placed in a room that is capable of providing the cooling and dust free environment to the server. It is very advisable that the server room should be very secure and only the authorized persons like (network administrators or other users) be allowed to enter in the server room.

Group_15:Krazzy4:Transmission Media

Transmission Media – Guided

There are 2 basic categories of Transmission Media:

Guided and
Unguided.

Guided Transmission Media uses a “cabling” system that guides the data signals along a specific path. The data signals are bound by the “cabling” system. Guided Media is also known as Bound Media. Cabling is meant in a generic sense in the previous sentences and is not meant to be interpreted as copper wire cabling only.

Unguided Transmission Media consists of a means for the data signals to travel but nothing to guide them along a specific path. The data signals are not bound to a cabling media and as such are often called Unbound Media.

There 4 basic types of Guided Media:

Open Wire
Twisted Pair
Coaxial Cable
Optical Fibre

Open Wire

Open Wire is traditionally used to describe the electrical wire strung along power poles. There is a single wire strung between poles. No shielding or protection from noise interference is used. We are going to extend the traditional definition of Open Wire to include any data signal path without shielding or protection from noise interference. This can include multiconductor cables or single wires. This media is susceptible to a large degree of noise and interference and consequently not acceptable for data transmission except for short distances under 20 ft.

Twisted Pair

The wires in Twisted Pair cabling are twisted together in pairs. Each pair would consist of a wire used for the +ve data signal and a wire used for the -ve data signal. Any noise that appears on 1 wire of the pair would occur on the other wire. Because the wires are opposite polarities, they are 180 degrees out of phase (180 degrees – phasor definition of opposite polarity). When the noise appears on both wires, it cancels or nulls itself out at the receiving end. Twisted Pair cables are most effectively used in systems that use a balanced line method of transmission: polar line coding (Manchester Encoding) as opposed to unipolar line coding (TTL logic).

The degree of reduction in noise interference is determined specifically by the number of turns per foot. Increasing the number of turns per foot reduces the noise interference. To further improve noise rejection, a foil or wire braid shield is woven around the twisted pairs. This “shield” can be woven around individual pairs or around a multi-pair conductor (several pairs).

Cables with a shield are called Shielded Twisted Pair and commonly abbreviated STP. Cables without a shield are called Unshielded Twisted Pair or UTP. Twisting the wires together results in a characteristic impedance for the cable. A typical impedance for UTP is 100 ohm for Ethernet 10BaseT cable.

UTP or Unshielded Twisted Pair cable is used on Ethernet 10BaseT and can also be used with Token Ring. It uses the RJ line of connectors (RJ45, RJ11, etc..)

STP or Shielded Twisted Pair is used with the traditional Token Ring cabling or ICS – IBM Cabling System. It requires a custom connector. IBM STP (Shielded Twisted Pair) has a characteristic impedance of 150 ohms.

Coaxial Cable

Coaxial Cable consists of 2 conductors. The inner conductor is held inside an insulator with the other conductor woven around it providing a shield. An insulating protective coating called a jacket covers the outer conductor.

The outer shield protects the inner conductor from outside electrical signals. The distance between the outer conductor (shield) and inner conductor plus the type of material used for insulating the inner conductor determine the cable properties or impedance. Typical impedances for coaxial cables are 75 ohms for Cable TV, 50 ohms for Ethernet Thinnet and Thicknet. The excellent control of the impedance characteristics of the cable allow higher data rates to be transferred than Twisted Pair cable.

Optical Fibre

Optical Fibre consists of thin glass fibres that can carry information at frequencies in the visible light spectrum and beyond. The typical optical fibre consists of a very narrow strand of glass called the Core. Around the Core is a concentric layer of glass called the Cladding. A typical Core diameter is 62.5 microns (1 micron = 10-6 meters). Typically Cladding has a diameter of 125 microns. Coating the cladding is a protective coating consisting of plastic, it is called the Jacket.

group15_krazzy4:Bluetooth Technology

WHAT IS BLUETOOTH?
Bluetooth is an open specification for a radio system that provides the network infrastructure to enable short range wireless communication of data and voice. It comprises of a hardware component and a software component. The specification also describes usage models and user profiles for these models. Bluetooth is named after the Danish King Harald Blaatand “Bluetooth”, who successfully united Denmark and Norway during his rule from 940 to 985 AD.Bluetooth unleashes the concept of “hidden computing” by providing radio devices “unconscious” connectivity without the user’s proactive intervention. It provides a bearer service for wireless (WAP) applications.

BLUETOOTH CHARACTERISTICS:-
Bluetooth radios operate in the unlicensed ISM band at 2.4 Gigahertz using 79 channels between 2.402 GHz to 2.480 GHz (23 channels in some countries). The range for bluetooth communication is 0-30 feet (10 meters) with a power consumption of 0dBm (1mW). This distance can be increased to 100 meters by amplifying the power to 20dBm. The bluetooth radio system is optimized for mobility.
Bluetooth supports two kinds of links: Asynchronous Connectionless (ACL) links for data transmission and
Synchronous Connection oriented (SCO) links for audio/voice transmission. The gross bluetooth data rate is 1 Mbps while the maximum effective rate on an asymmetric ACL link is 721 Kbps in either direction and 57.6 Kbps in the return direction. A symmetric ACL link allows data rates of 432.6 Kbps. Bluetooth also supports up to three 64Kbps SCO channels per device. These channels are guaranteed bandwidth for transmission.

TECHNOLOGY COMPARISON:-
Since bluetooth operates in the unlicensed ISM band that is also used by other devices such as 802.11 networks, baby monitors, garage door openers,microwave ovens etc, there is possibility of interference.
Bluetooth uses Frequency Hop Spread Spectrum (FHSS) to avoid any interference. A bluetooth channel
is divided into time slots each 625 micro second in length. The devices hop through these timeslots making
1600 hops per second. This trades bandwidth efficiency for reliability, integrity and security.

BLUETOOTH ARCHITECTURE:-
Bluetooth communication occurs between a master radio and a slave radio. Bluetooth radios are symmetric
in that the same device may operate as a master and also the slave. Each radio has a 48 bit unique device address (BD_ADDR) that is fixed. Two or more radio devices together form ad-hoc networks called piconets. All units within a piconet share the same channel. Each piconet has one master device and one or more slaves. There may be up to seven active slaves at a time within a piconet. Thus each active device within a piconet is identifiable by a3 bit active device address. Inactive slaves in unconnected modes may continue to reside within the piconet.
A master is the only one that may initiate a bluetooth communication link. However, once a link is established,
the slave may request a master/slave switch to become the master. Slaves are not allowed to talk to each other directly. All communication occurs within the slave and the master. Slaves within a piconet must also synchronize their internal clocks and frequency hops with that of the master. Each piconet uses a different
frequency hopping sequence. Radio devices used Time Division Multiplexing (TDM). A master device in a piconet transmits on even numbered slots and the slaves may transmit on odd numbered slots. Multiple piconets with overlapping coverage areas form a scatternet. Each piconet may have only one master, but slaves may participate in different piconets on a time-division multiplex basis. A device may be a master in one piconet and a slave in another or a slave in more than one piconet.