Thursday, April 29, 2010

Source-route bridging algorithm

What is source-route bridging algorithm?

Ans:
The source-route bridging (SRB) algorithm was developed by IBM and was proposed to the IEEE 802.5 committee as the means to bridge between all LANs. SRBs are so named because they assume that the complete source-to-destination route is placed in all inter-LAN frames sent by the source. SRBs store and forward the frames as indicated by the route appearing in the appropriate frame field. Assume that Host X wants to send a frame to Host Y. Initially, Host X does not know whether Host Y resides on the same LAN or a different LAN. To determine this, Host X sends out a test frame. If that frame returns to Host X without a positive indication that Host Y has seen it, Host X assumes that Host Y is on a remote segment. To determine the exact remote location of Host Y, Host X sends an explorer frame. Each bridge receiving the explorer frame copies the frame onto all outbound ports. Route information is added to the explorer frames as they travel through the internetwork. When Host X's explorer frames reach Host Y, Host Y replies to each individually, using the accumulated route information. Upon receipt of all response frames, Host X chooses a path based on some predetermined criteria. Host X must select one of these two routes. The IEEE 802.5 specification does not mandate the criteria that Host X should use in choosing a route, but it does make several suggestions, including the following:
•First frame received
•Response with the minimum number of hops
•Response with the largest allowed frame size
•Various combinations of the preceding criteria
In most cases, the path contained in the first frame received is used.

Linked list

How do we check whether a linked list is circular?

Ans:
To check for it, create two pointers,and set each to the start of the list. Update each as follows:

while (pointer1) {
pointer1 = pointer1->next;
pointer2 = pointer2->next;
if (pointer2) pointer2=pointer2->next;
if (pointer1 == pointer2) {
print ("circular linked list\n");
}
}

Resume Tips

1. USE ATTRACTIVE FORMATTING

Five minutes. That's all you have to grab the reader's attention and market yourself effectively. You can achieve this with attractive formatting.
The key is to have a good balance of white space and text. Your résumé should not look empty, nor should it overwhelm the reader with text. Keep margins of at least 1" on all sides (some companies may still keep your résumé "on file" i.e. in three-ring binders). Make the résumé readable by using a minimum of a 10-point font for text and 11-point for headings. Use, at most, three levels of formatting (normal text, bold, and italics) or else it will distract the reader. Remember, although you want to get the reader's attention, do so with communicative titles and descriptions rather than with fancy fonts and graphics.
A badly formatted résumé will look sloppy. If you submit such a document, you might as well forget about the interview.
2. COVER THE BASICS

The key point here is to not complicate matters for the reader. They should be able to obtain all pertinent information about you without moving from their chair (yes, it sounds ludicrous, but that's how it needs to be). So, make sure that your résumé contains the following information.
• Contact Information like name, address, phone/fax numbers, and email address.
• Objective. A single statement should sum up your goals.
• Education. If you've graduated recently and want to highlight it, place education before the experience and skills section and list your coursework. List GPAs only if they are good. Education should always be listed in reverse chronological order. Assuming that you have an undergraduate degree, do not list your high school education since it is irrelevant.
• Work Experience. Again, this must be listed in reverse chronological order, and must include the company title, location, timeframe of work there, responsibilities and projects. More on this later.
• Publications, Patents, and Awards. List these or anything else that is relevant to your job function in this section. If you have many publications and patents, consider listing them on a separate page and attach it to your résumé.
• Computer Skills. This section can include hardware, software, programming language, and operating system experience. It's not necessary to include everything, but do make sure you list a few critical items which can be caught by résumé tracking software.
• Other Skills and Activities. This section can be used to show that you are a well-rounded individual. It can include membership in industry-related societies. Keep it short, general, and avoid controversial hobbies or pastimes.
If you have many years of experience, you can also provide a summary of your skills before the "Experience" and "Education" sections.
I've seen many résumés where people forgot to list their phone numbers, had glaring holes in their work experience and schooling, or did not mention their objective. Such deficiencies raise questions in the mind of the reader, and make his or her life more difficult by asking them to find information. Do you really want to do that, especially when there are hundreds of people applying for the same job?
3. BE CONCISE AND COMMUNICATE RELEVANT INFORMATION

In the high-tech world, it is likely that managers who appreciate brevity will evaluate your résumé. So, keep the length in check. Follow the general rule of the thumb, one page for every eight years of experience. Also, don't repeat information.
However, do not err on the side of extreme conciseness. The goal is to communicate your experience and separate yourself from the competition. Consider the following examples of information that is too concise, appropriate, and too detailed.
"Designed a K6 motherboard for a sub-\$1000 PC"
Too concise. Does not convey details of critical components, nor does it discuss applications.
"Designed a motherboard using the K6 processor, 430TX chipset and associated peripherals. Target applications were sub-\$1000 PCs. To lower cost, graphics acceleration was integrated on-board."
Appropriate. Discusses critical components, architecture, and applications.
"Designed a motherboard using the K6 processor, 430TX chipset, Ultra-I/O controller, SDRAM, 512 KB of cache memory, clock generator, PCI and ISA slots, and a graphics accelerator with 4MB of memory on board. The system was targeted at sub-\$1000 PCs being manufactured by various large computer makers in the US, Europe, and Asia."
Too long. Details that can be discussed in the interview are presented here. The statement about computer makers is irrelevant.
4. USE ACTION AND POWER WORDS

It is important that you use action words that convey activity. In the previous examples, the sentence could just as easily have begun with "Worked on a motherboard..." However, beginning the sentence with "Designed a motherboard..." eliminates ambiguity and conveys action.
A conscious effort must be made to use action and power words in your résumé. The types of words you can use depend on the job function. If you are applying for a management position, then use words like "Managed, supervised, led," etc. If you are applying for an engineering position, then incorporate words such as "Designed, developed, debugged," etc. A list of action words can be available through online thesauruses, reference books on résumé writing, and even paper manufacturing companies. Remember, it is also important to communicate teamwork and leadership qualities, especially if you are applying for a managerial position.
I've noticed that many Indians do not use action and power words when writing résumés. This is probably a cultural trait, since we're taught to understate our achievements and write in passive tense. Eliminate this habit when writing résumés.
5. BE FAMILIAR WITH THE INFORMATION

An interviewer does not want to hear "Well, I worked on that project a long time ago and so I cannot answer your question." This is unacceptable and you have just shot yourself in the foot. If you are not familiar with the material, it conveys that either you did not do the work, or that you forget easily and cannot leverage off past experience, or that you have prepared poorly for the interview. Bottom line, either exclude such information from your résumé, or familiarize yourself with it.
6. BE CONSISTENT

It's fine to be creative, but consistency plays a far more important role. It conveys a logical and organized thought process and leaves a positive impression in the engineering-centric high-tech world. Here's an example of consistency: When providing a summary of your accomplishments, begin each line item with an action word, as shown below by the underlined text.
• Created and executed strategy to triple product line revenues in two years.
• Defined and developed four product families encompassing over 30 devices to meet revenue goals.
• Wrote all product data sheets and collateral for these 30 products.
Another example is to consistently stay in third person rather than shifting between first and third person in the document. Please refrain from using "I" in your résumé.
A general rule of the thumb is that each section of the résumé should have subsections that look very similar. For example, if your "Work Experience" section contains a paragraph on responsibilities, followed by subsections on major projects and accomplishments, it should be the same for every employer.
Different sections should resemble each other in terms of formatting, to ensure that information can be located easily.
7. DON'T LIE

You will be caught. Enough said.
8. BE BUZZWORD COMPLIANT

Since screening is routinely performed by software, you must use buzzwords on your résumé. Don't enumerate everything in your repertoire, but do list basic skills that are necessary for the job, or are currently in demand. Obviously, include these abilities only if you possess them.
9. PERFORM SPELLING AND GRAMMAR CHECKS

Most good interviewers do not accept more than three minor mistakes in a résumé, since it indicates your inability to perform high-quality work. Hence, after you have completed your résumé, check for spelling and grammar errors. All word processing packages include tools to do the same, so that's going to be your first level check. Additionally, have someone proof read the document to catch errors missed by the software.
Some common errors that I have see on résumés are: random double spaces between words, two periods at the end of a sentence, misspelling your University or company name, missing prepositions in a sentence, and a lack of commas in a long sentence.
10. CUSTOMIZE YOUR RESUME

One résumé does not fit all. It's okay to customize the résumé based on the job requirements. Customization sells your skills more effectively and results in more job interviews for you.
When applying for the job, don't forget the cover letter. The purpose of this document is to augment your résumé's critical sections (i.e. those that are applicable to the target job). The maximum length of a cover letter is one-half of a page, ideally separated into three paragraphs. The first tells the reader how you heard of the job, the second discusses your relevant skills, and the third tells the reader why you are a great fit. It goes without saying that a cover letter must be concise.
Since email is now very popular, a short cover letter can be written in the text of the email. However, email does raise the question of how to submit your résumé. In this case, the fundamental rules always apply: follow the company directions, and if they don't specify, ask. If you get no response, use the default, which is a text email with a Word attachment.