Drawbacks Of Traditional Ip Forwarding Information Technology Essay

Drawbacks Of Traditional Ip Forwarding Information Technology Essay Service provider network has a requirement to fast switching without any routing lookup in the core network and not to load the traffic in core network. If traffic congested in core network it makes a big delay whole network traffic switching. As a result MPLS technology has been introduced. MPLS is a packet forwarding technology used in service provider core network for fast switching of packets. MPLS technology uses label technology to switch the packets rather than traditional destination IP based mechanism. Multi Protocol Label Switching (MPLS) is a packet forwarding technology used in the service provider core network. MPLS uses the labels to packet forwarding instead of traditional destination IP based mechanism to integrate the layer 2 information such as bandwidth, latency, utilization with layer 3 (IP) elements. MPLS Labels usually correspond to IP destination networks. Labels also correspond to other parameters such as Quality of Service (QoS), source address or layer 2 circuits. Label switching is regardless of layer 3 protocol. MPLS is called multiprotocol because it works with the Internet Protocol (IP), Asynchronous Transport Mode (ATM), and frame relay network protocols. Why MPLS MPLS is a protocol neutral MPLS is designed to integrate layer 2 information about network links (bandwidth, latency, utilization) into layer 3 (IP) elements. That allowed MPLS to work with ATM, Frame Relay and Ethernet at the core Drawbacks of Traditional IP forwarding Routing protocols are used to distribute Layer3 routing Information. Regardless of routing protocol, routers always forward packets based on the destination address only. Destination based routing does not provide any mechanism for load balancing across unequal paths. Routing lookups are performed on every hop. This is much over head to every hop and it makes delay on forwarding packets since, the routing table consists hundreds of thousands routes. Routing complexity depends on the size of routing table. MPLS is adaptable MPLS is able to support new application and services such as layer 2 layer 3 VPNs, Ethernet services and traffic engineering. MPLS is cost effective solution In case of VPN provision, Service providers use one centralized network to connect number of sites of a customer. Likewise several customers are served using a single MPLS network. Traditional IP forwarding Technology Traditional IP based technology designed based on routing protocols which used to distribute layer3 routing information, Destination based packet forwarding technology and routing lookup on every hop. When packets reach the nodes for routing, All the nodes (routers) in the network, will have a destination address based lookup in the routing table which is the data base provides for which destination packets has to be routed through which interface. Policy based routing is only exception for destination based routing. The following figure shows the traditional IP forwarding mechanism. Figure2. Traditional IP forwarding Technology As a packet of a connectionless network layer protocol travels from one router to the next, each router makes an independent forwarding decision for that packet. That is, each router analyzes the packets header, and each router runs a network layer routing algorithm. Each router independently chooses a next hop for the packet, based on its analysis of the packets header and the results of running the routing algorithm. Packet headers contain considerably more information than is needed simply to choose the next hop. Choosing the next hop can therefore be thought of as the composition of two functions. The first function partitions the entire set of possible packets into a set of Forwarding Equivalence Classes (FECs). The second maps each FEC to a next hop. Insofar as the forwarding decision is concerned, different packets which get mapped into the same FEC are indistinguishable. All packets which belong to a particular FEC and which travel from a particular node will follow the same path (or if certain kinds of multi-path routing are in use, they will all follow one of a set of paths associated with the FEC). In conventional IP forwarding, a particular router will typically consider two packets to be in the same FEC if there is some address prefix X in that routers routing tables such that X is the longest match for each packets destination address. As the packet traverses the network, each hop in turn re-examines the packet and assigns it to a FEC. Drawbacks of Traditional IP forwarding As shown in the diagram, router does a routing lookup for each packet in a large routing database. The destination based routing lookup is forward through longest prefix match of the destination IP address. Each router has to do the same job until the packet reaches the destination. It makes more latency on packet delivery, processing load for routers. Service provider core network is running with much loaded traffic. Normal routers canà ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬Ãƒ ¢Ã¢â‚¬Å¾Ã‚ ¢t perform packet forwarding based on traditional ip forwarding technology. MPLS Applications Figure3.MPLS Applications Virtual Private Network (VPN) MPLS VPN application is one of the main targets of the project. MPLS provides a secure inter sites connectivity without any complexity for customers who have number of branches all over the country. VPN connectivity between the branches over MPLS is a big business for service providers and a main application over MPLS. The Reason for MPLS VPN rapid growth amongst the customers is MPLS allows service providers to create new VPNs without having to install new hardware; it significantly reduces the cost of implementation, which in turn reduces the overall cost of VPNs. Other reason is small and Medium Enterprise (SME) customers donà ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬Ãƒ ¢Ã¢â‚¬Å¾Ã‚ ¢t want to put the IT infrastructure with new hardware such as Firewalls to interconnect the sites (branches). Since, it is a big investment for them and more complex to manage the inter connectivity between branches. Next of all, MPLS provides a centralised control over the connectivity of branches. Customers only need to provide only one connection from their office router to the service provider rather than setting up and managing individual points between each office. This central control effectively removes the need for additional trained manpower. Additional benefits can be realised through this central management as a business is given greater control of Internet usage as well. The following figure shows how a service provider connects several customers using MPLS as a centralised point without complexity Another reason is VPN over MPLS is more secure than connecting entire sites using firewalls because there is no separate private network for a customer in such a situation. Each siteà ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬Ãƒ ¢Ã¢â‚¬Å¾Ã‚ ¢s firewall will establish connectivity over the internet using IPSEC. It makes much security threat over the data. Other MPLS Applications MPLS QoS MPLS quality of service helps to classify the traffic such as voice, data, signaling, best effort and other traffics and guarantee the allocated bandwidth Traffic engineering One of the most obvious advantages of MPLS is that it provides customers with a number of tools for traffic engineering. An MPLS network can offer the same sort of quality of service guarantees that data transport services like Frame Relay or ATM can, without requiring the use of any dedicated lines. Multicast routing Protocol Independent Multicast (PIM) is the control protocol used to create FEC tables; extensions of version 2 of the PIM protocol are used to exchange FEC-label binding. Pseudowires These can be used to evolve legacy networks and services, such as Frame Relay, ATM, PPP, High-Level Data Link Control (HDLC), and Ethernet. Traffic is accepted into the network via a variety of access technologies, labeled at the edge, and transported over a common MPLS core. At the network egress, the label is removed and delivered in a manner similar to the ingress implementation. Generalized MPLS (GMPLS) The goal of GMPLS is to integrate control of the routing layer with that of the optical transmission layer, thus facilitating the implementation of traffic engineering across the network. Optical cross-connect platforms do not examine traffic passing through themà ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬in contrast to routers, for example. GMPLS deployment links capacity provisioning in the optical layer for an automated execution of resource reservation (for example, bandwidth brokering and provisioning). MPLS Architecture MPLS architecture consists of two planes such as Forwarding plane and Control plane. The above diagram shows the conceptual diagram of MPLS architecture. The MPLS control plane is a collection of protocols that collectively establish network level functionality in MPLS networks. The protocols are implemented as software in routers. They will communicate with each other and transfer signaling information. Protocols specify the message formats, syntax, semantics, and transaction sequence for the message exchange. The main functionality performed by the control plane is to establish the Label Switched Path for packet forwarding. The data plane is used for the transport of packets (or label swapping algorithm). This separation permits applications to be developed and deployed in a scalable and flexible manner. MPLS Operation The above diagram shows the MPLS functionality. The edge routers of the MPLS cloud is known as Label Edge Routers (LERs) or Provide Edge routers (PE Routers). These edge routers are designed to inspect IP packets entering the network and add MPLS headers, as well as removing the headers from packets leaving the MPLS network. In central of the MPLS cloud there are four backbone routers placed. These routers are known as Label Switch Routers (LSRs) or P routers look for an MPLS label on each packet that passes through them, looking up and following the instructions contained in those labels, routing them based on a list of instructions. MPLS allows administrators to define routes known as Label Switched Paths (LSPs) from one LER to another, through a series of LSRS, across the MPLS network. These LSPs are pre-assigned and pre-engineered paths that packets with a certain label should follow. MPLS Labeling Forwarding Equivalency Class (FEC) is used in MPLS to describe the identical characteristics packets which may forward in the same way. Characteristics determine the FEC of the packets but typically it is at least destination IP address. FEC consists of a group of IP destinations for which a fixed-length identifier is assigned which is called label. The path corresponding to each FEC between the ingress (PE router which accept the packets to MPLS cloud) and egress (PE router which send off the packets out to MPLS cloud) LSRs is called Label Switched Paths (LSP). An FEC, therefore, determines how packets are mapped to an LSP. A label is assigned to the FEC imposition operation either by tagging an existing field or as a complement in the packet header. The label is pivotal to the establishment of the LSP through all the routers. Each LSR analyzes the incoming packet label. Then after consulting a label table that permits it to recognize the LSP, the LSR switches the packet to the next LSR after changing the value of the label. The label is removed at the egress LSR or a disposition operation is performed.

Users select their destinations

Users select their destinations GROUP ASSIGNMENT PART Study the following case study and answer all the tasks listed. An automated ticket-issuing system sells rail tickets as you find in London underground and over ground railway stations. Users select their destinations and can be pay cash the exact amount or input a credit card and a personal identification number (PIN). The rail ticket is issued and their credit card account charged if the ticket was bought using a credit card. When the user presses the start button, a menu display of potential destinations is activated, along with a message to the user to select a destination. Once a destination has been selected, users are requested to pay cash or input their credit card. In the last case, its validity is checked and the user is then requested to input a personal identifier. When the credit transaction has been validated, the ticket is issued. ambiguities or omissions in the above scenario An automatic ticket issuing system sells rail tickets. Users select their destination, and input a credit card and a personal identification number. The rail ticket is issued and their credit card account charged with its cost. When the user presses the start button, a menu display of potential destinations is activated along with a message to the user to select a destination. Once a destination has been selected, users are requested to input their credit card. Its validity is checked and the user is then requested to input a personal identifier. When the credit transaction has been validated, the ticket is issued. Ambiguities and omissions include: Can a customer buy several tickets for the same destination together or must they be bought one at a time? Can customers cancel a request if a mistake has been made? How should the system respond if an invalid card is input? What happens if customers try to put their card in before selecting a destination (as they would in ATM machines)? Must the user press the start button again if they wish to buy another ticket to a different destination? Should the system only sell tickets between the station where the machine is situated and direct connections or should it include all possible destinations? What type of input device (touch screen vs. keyboard)? Ticket prices Room on train (assumes tickets have times on them) Train departure and arrival times. Do customers buy tickets for a specific train? Or for any trip along the route? (If the latter, then no way to tell if all the seats on a train are sold out, nor can you do seat assignments.) Seat assignments (see above) Print receipt? identified ambiguities in some appropriate way. Function Give customer a rail ticket, and charge credit account or take cash from customer and give the customer, a rail ticket. Description Determine customers destination, calculate the charge for the trip, and charge the customer the appropriate amount. If charge is complete, print the ticket, otherwise, print no ticket, and report error to customer. Inputs Destination, credit card number and PIN. Outputs Tickets, error messages Action Ask the customer for their destination, when input, calculate the total, and prompt to insert a credit card, prompt customer for PIN, prompt customer that the transaction is taking place, if successful print the ticket and return to start state, if unsuccessful, ask customer to swipe their card again and re-input the PIN. If unsuccessful again, prompt that the transaction has failed, and return to start state. Requires Destination, credit card number and PIN Pre-condition None Post-condition None Side effects Charge to the customers credit account user requirements definitions The user requirements for a system should describe the functional and nonfunctional requirements so that they are understandable by system users without any technical knowledge. When we write the user requirement we should not write with technical forms, table or diagrams. We should write in simple language with simple table, forms and diagrams. The actors in the system are the passenger, the counter clerk and the reservation system consisting of form processing, reservation, fare computation, ticket processing, ticket printing, collection of fare amount and posting as sub-systems. The passenger is a passive user-actor who initiates the process and obtains the ticket(s), a goal of measurable value. The counter clerk is an active user-actor, who triggers the system and has the role of issuing the tickets with the responsibility of collecting the correct fare amount from the passenger, which is a measurable value. Predesigned and deployed ticket reservation system at the back end is a system actor-user to ensure that ticket processing is done correctly and different system statuses are updated on issuing of tickets. This actor has an active role and responsibility at the back end. system requirements specifications System requirements Specifications are specified using the standard way of these forms. Function: Issuing Ticket Description: Issuing the ticket when the user select their desired tickets and make the correct payment. Inputs: Destination, child or Adult ,Pay by card or cash Output: Their desired ticket to be issued with their payment receipt Requires : Money Pre- Condition: Ticket will be validate between the user current place and the selected destination, Otherwise user will have to pay the penalty fare. a sequence diagram Scenario 1 This diagram shows about the user wants their ticket from the machine. It shows the interaction between user and ticket machine where user puts the requirement to the machine and the machine gives options back to the user. Scenario 2 This diagram shows the user chose the station and the machine give option back to user needs to choose from following option for e.g return ticket which class user wants to travel. After selecting options the user needs to pay for payment machine give option for eg cash or card. If the user choose card the ticket machine need to validate from card user. Scenario 3 This diagram represents a sequence activity when user buy a ticket using credit or debit card. When the user insert the card. The card is validated with the card issuer the validation of the card is returned to machine which then displays the result to the user. If the card is valid then the user need to enter the pin. The validity of the pin is checked. If the pin is wrong user need to try again. Once completed the user account is credited and the ticket along with the receipt to the user. Non-functional requirements The ticket system shall respond to user inputs to provide tickets and charge accounts in a timely manner. The system shall continue to function so long as roll of ticket paper is in the machine, and a network connection is provided for the destination database and credit transactions. Upon receipt of the destination from the user, the database shall be accessed to determine the distance from the units location, to the desired destination, and calculate the appropriate fee. The unit shall then prompt the user to input their card information, and the unit shall verify that the card is a credit card, is valid, and has sufficient credit to be charged. Upon successful verification, the unit shall print a ticket, and return to its ready state, for the next transaction to take place. The reliability this system relies on the durability of the physical user interface, the network connection in the area the system is placed, the size of the ticket rolls that the unit can accept, and the mecha nism for dispensing the tickets. The estimated time for a complete transaction would be about thirty seconds, giving twenty for the user interactions, five for validation and verification of the users account, and five for printing and dispensing the ticket. Use-cases Requirements validation process. Customer inserts her credit card into the ticket machine. card provider checks the card number. Then the machine asks for the pin-code. User enters the pin-code. Then the ticket machine requests database to validate the credit card. Ticket on processes. customer can use the ticket finaly. A semantic data model Impact if when the customer pays cash As the sequence diagram shows, the customer goes to ticket machine, and he is allowed to not have axact amount, the machine will confirm the amount, go through the check process and issues the ticket with receipt. References and Bibliography: Sommerville (2007), Computer Information Technology in Processors, 8th Edition, www.pearsoned.co.uk, Use Diagram (2010) Unified Approach and Unified Modeling Language. [Online].Available from: http://highered.mcgraw-hill.com/sites/dl/free/0070583714/214723/144USECASEDIAGRAM.pdf [Accessed 13 Feb 2010]

Time, Talent and Tangible Resources :: essays research papers

Time, Talent and Tangible Resources It is difficult to believe that it is already time to write my fourth and final column as president of NCSEA for the Child Support Quarterly. Although this is my last major writing assignment, many opportunities to be of service to the child support community remain available between now and August 2, 2000, and I assure you that I will avail myself of as many of them as are humanly possible. I decided to close out my series of these columns by sharing with the broader NCSEA family my personal view of what our beloved child support program should look like in the future. I have long held that the child support program needs to look much more like the backroom of MasterCard, Visa or American Express rather than a cash assistance program. There is little question that the child support program was the cash assistance program designed to provide comprehensive reinforcements to families in need. Child support, as well as the other programs in our income assistance system, has a unique contribution to make to family well-being. The question is: how can child support best make that contribution. Whatever else may be added to or subtracted from it, I believe, child support’s core functions will always include establishing paternities, locating noncustodial parents obligated to pay child support, establishing support orders, enforcing those orders, collecting and distributing child support payments. I would suggest the customer service centers for this country’s credit card industry hold some valuable and transferable approaches that can be used to improve not only the delivery of child support services, but also the public perception of the child support community. Just think about it. When you call your credit card company about a recent purchase or their failure to properly credit a recent payment, you don’t even know, let alone have a long-standing relationship with, the customer service representative. They do not have to â€Å"case manage† you in order to provide you with value added service. You simply make the call, state your problem and get the information you need. The customer service representative has the appropriate charge investigated (with the understanding that the charge will be removed from your account in the interim), sends you a letter verifying the nature of this interaction and you move on a happy camper - at least for the moment. That is the level of service that the American public has come to expect in their daily business transactions, and that is the level service that the public anticipates from the child support program.

What is in yours? :: science

What is in yours? From the moment parents bring their new baby home from the hospital, they watch their baby's progress, anticipating every inch of growth and each new developmental milestone along the way. But what exactly are they watching for and how do parents know if their child is growing properly? Growth is the various physical and developmental milestones that most children reach during each age level. Physical growth, which is generally measured in terms of height, weight and head growth, is also monitored carefully. This includes increases in height and weight as well as development in cognitive, language, and social skills. Hair grows; teeth come in, come out, and come in again; and eventually puberty hits. It's all part of the growth process. The first year of an infant's life is a time of astonishing change. During this time, a baby will grow rapidly and achieve major developmental milestones, such as taking first steps or maybe even saying a few first words. On average, babies grow 10 inches in height while tripling birth weight by their first birthday. Beginning in infancy, a child will visit a doctor for regular checkups. At each of these visits, the doctor will record the child's height and weight on a growth chart. This chart shows the doctor and parents how the child's height and weight compare to that of other children the same age. This can help your child's doctor determine whether your child is growing at an appropriate rate or whether there might be any problems. After age 1, a baby's growth in length slows considerably, and by 2 years, growth in height usually continues at a fairly steady rate of approximately 2 1/2 inches per year until adolescence. No child grows at a perfectly steady rate throughout this period of childhood, however. Weeks or months of slightly slower growth alternate with mini growth spurts in normal children. Kids actually tend to grow a bit faster in the spring than during other times of the year. A major growth spurt occurs at the time of puberty. Around ages 8 to 13 in girls and 10 to 15 in boys, kids enter puberty, which lasts from about 2 to 5 years. By the time girls reach age 15 and boys reach age 16 or 17, the growth associated with puberty will have ended for most teens and they will have reached physical maturity.

Herbal Medicine :: essays research papers fc

Herbal Medicine I would like to start out by saying a verse from Genesis 1:29-30 â€Å"And God said, behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat. And to every beast of the earth, and to every fowl of the air, and to everything that creepeth upon the earth, wherein there is life, I have given every green herb for meat: and it was so.† This verse from the bible has a powerful, but simple meaning; all herbs shall be taken in to our body as the meat for healing. I not only believe in herbs because it is said in the bible, but because herbal medicine has the power to prevent & heal. Why?, well, its quite simple really, our bodies are organic, so, why would you want to take in something that’s inorganic, would it not be wiser to allow the body to heal with organic products. That’s exactly what you are doing when taking pain relievers, heparin, and antihypertensive medications just to name a few. In herbal medicine, the patient is empowered, and since herbs are certainly more convenient, without prescriptions or limitations, more patients can enjoy their benefits. The benefits which I’m speaking of is the ability to prevent & heal. Let’s take cardiovascular disease for example, which just happens to be the leading cause of death in the U.S., and according to Dr. David Vastola in his book To y our good health, he wrote out a section with a natural alternative for CAD and hypertension, how, well he says by taking in Omega 3, L-Carnitine, and Coenzyme Q10, that these 3 things can help a person to cope with CAD, and as for hypertension all they have to do is either to take Coenzyme Q10 or Hawthorne. Have we all here heard one time or another that ulcers are cause by stress, well, the NIH said that ulcers are caused by the helicobacterpylori bacteria, not by stress, and the NIH said that they can be â€Å"cured† with a combination of the trace mineral bismuth and tetracycline. The number two cause of death in America as we all know is Cancer, well, the NCI (Sept 1993) and Harvard Medical School performed a study on cancer patients, and the results were that they found an anti-cancer diet.

paganbeo Pagan Aspect of Beowulf Essay -- Epic Beowulf essays

The Pagan Aspect of Beowulf      Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In Beowulf the pagan aspect is revealed through many passages and many heathen rites or customs in which the form of expression or the thought suggests pagan usage or beliefs.    â€Å"The poet’s heroic age is full of men both ‘emphatically pagan and exceptionally good,’ men who believe in a God whom they thank at every imaginable opportunity. Yet they perform all the pagan rites known to Tacitua, and are not Christian† (Frank 52). Certainly the pagan element seems to be too deeply interwoven in the text for us to suppose that it is due to additions made by scribes at a time when the poem had come to be written down. The pagan element had to be included by the original poet. Another scholar considers the paganism of the poem:    Both the poet and his audience knew well that sixth-century Scandinavians were heathens. And lest it be thought that Anglo-Saxons tended to forget the heathenism of the Scandinavians as time wore on, we should recall that, in the Chronicle, charters, poems, and saints’ lives, Old English haethen (as well as Latin paganus) was virtually a synonym for Dene (i.e. â€Å"Scandinavian†). Indeed, the association between heathenism and Scandinavians became ever so stronger in Anglo-Saxon England as the centuries passed. The vaguely pious heroes of Beowulf, then, would not have been mistaken for christians by an Anglo-Saxon audience (Robinson 82).    The extent to which the pagan element is present varies in different parts of the poem, but is present throughout from beginning to end. The pagan element is unequally distributed between the speeches and the narrative, favoring the narrative.    Catholic missionaries to Britain in the early ce... ...by Lewis E. Nicholson. Notre Dame, IN: University of Notre Dame Press, 1963.    Bloom, Harold. â€Å"Introduction.† In Modern Critical Interpretations: Beowulf, edited by Harold Bloom. New York: Chelsea House Publishers, 1987.    Chadwick, H. Munro. â€Å"The Heroic Age.† In An Anthology of Beowulf Criticism, edited by Lewis E. Nicholson. Notre Dame, IN: University of Notre Dame Press, 1963.    Chickering, Howell D.. Beowulf A dual-Language Edition. New York: Anchor Books, 1977.    Frank, Roberta. â€Å"The Beowulf Poet’s Sense of History.† In Beowulf – Modern Critical Interpretations, edited by Harold Bloom. New York: Chelsea House Publishers, 1987.    Robinson, Fred C. â€Å"Apposed Word Meanings and Religious Perspectives.† In Beowulf – Modern Critical Interpretations, edited by Harold Bloom. New York: Chelsea House Publishers, 1987.

Helen Gardner :: Helen Gardner Essays

Helen Gardner In act one scene one we discover that Helen is a very down to earth type of person as she says â€Å"when I find somewhere for us to live I have to consider something far more important than your feelings. . . .The rent†, this shows that she is thinking about the more important things in life, she is also emphasising the letter â€Å"I† which is implying that she is a lot better than her daughter, this also shows that she has a roof over Jo’s head. The beginning of this play shows that Helen enjoys drink, â€Å"pass me a glass Jo† the first thing that she thinks about is alcohol, this shows that if she can afford to buy whisky then she may have been able to find a better place for them to live, although the accommodation isn’t very appropriate it still provides Jo with a roof over her head, we also get the impression that she is an unfit parent as her priorities should be towards her daughter and not towards alcohol. Helen feels that Jo owes her a lot, Jo feels the total opposite, and there is not a close relationship, Helen feels that she deserves respect from Jo, most people may think that as Helen is Jo’s mother then Jo does owe her a lot but most people would think that Helen owes a lot to Jo as she hasn’t really been there for her daughter all these years, but as an adult Helen does deserve respect from her daughter no matter what she has done, because at the end of the day Helen did bring Jo into the world and has brought her up to be what she is now. As we can see in act one Jo shares a bed with Helen this is a redeeming quality because if Helen despised Jo that much she wouldn’t be willing to do this, because at the end of the day the both need somewhere to sleep. Helen has a very negative view on life as she says, â€Å"that’s where we all end up sooner or later†, this was related to Jo trying to decide where to put her bulbs, she felt that the best place to put them was in a cold dark place, the cold dark place meaning to Helen a grave, this is yet another reference of death which Helen seems to use. I think that by being a prostitute and sleeping around is a way for Helen to find someone to love her, she craves it. Helen seems to be addicted to men, She gives Jo a distorted view on