Trouble with Computer Networks
Each new year since the birth of the personal computer has been hailed as “the year of the network”. This year is different. This time it is “ the decade of the network”. Do not hold your breath.
Market researchers at Dataquest in Silicon Valley think that American companies’ worldwide sales of the hardware and software needed to make personal-computer networks will grow by about 25% a year for the next two or three years. That is faster than the growth expected for personal computers themselves, but still not the boom that many had predicted. The step-by-step evolution of computer standards makes booms unlikely.
Standards are the key to successful networking. If they arc to communicate, computers must all speak the same language. Everything from how to establish a connection over the telephone to how to detect and correct errors must be agreed in detail at the outset. Devising flexible, reliable standards takes time; building reliable programmes based on them takes yet more. To see how complicated the process can be, look at what ought to be a fairly simple step in the evolution of computer networks: the ability to share files between machines.
Most of the basic problems of sending the strings of Os and Is that make up computer data from machine to machine have been solved. This does not mean that one machine can be plugged straight into another, or that networks do not suddenly and mysteriously break down. But there are, at least, procedures for diagnosing and repairing breakdowns and overcoming incompatibilities. Computer files are merely named collections of data. In theory, knowing how to send data should make sending files a snap. Unfortunately, in computing, things are never so simple. There are three or four different “standards” for sharing files. The differences between them lie not so much in how they solve the problem, but in how they set it.
Start with the Network File System (NFS) created by Sun Microsystems, the leading manufacturer of high-powered Unix workstations. NFS is probably the best means of swapping files between different types of computers. It enables one computer to get at files stored on another as if they were its own. That is much harder than it sounds.
Simply getting Os and Is from one machine to another provides no guarantee that the recipient can make sense of them. The string of Os and Is which denotes the letter "A” on most IBM mainframes means something else altogether on an IBM PC — as does the string which denotes the number 3.14. NFS must translate from one to another. It must also keep track of details such as the different naming conventions for files used by different machines. Most personal-computer file names, for example, can be only 12 characters long. Those for other operating systems can be much longer.
But NFS is less good at letting personal computers share files among themselves. It was created for, and often runs on, high-powered workstations. These use the Unix operating system which does lots of things that Microsoft’s DOS (the most popular operating systems for personal computers) docs not. For example, it handles the co-ordination necessary for a computer to do two things at once. And Unix, unlike DOS, ensures that the computers in a network do not all try to get at the same file at the same time. The inventors of NFS, therefore, did not have to worry about such things.
When it came to working with DOS, America’s Novell, the leading maker of personal-computer networks, built these features into its technology. So did 3Com, its biggest rival. Meanwhile, Microsoft, the largest personal-computer software company, is taking another approach. To make best use of today’s more powerful personal computers, it is promoting a new operating system, called OS/2. Microsoft has joined up with 3Com to develop a new technology to get OS/2 to work with networks; it is called LAN Manager.
Because Microsoft built both the operating system and the network software, LAN Manager probably makes best use of the facilities OS/2 offers for managing communication over networks. But it is, inevitably, different from both DOS-based networking software and NFS. So customers face several choices even about the humble task of getting computers to share files. There is a yet more bewildering array of solutions to even more complicated problems, such as getting computers to share work. No wonder many customers want a bit of time to think before they buy; meanwhile the decade of the network ticks by.
Computer data consist of Os and Is.
Successful depends on standards.
A very important feature of networking is that computers .
Talking about the difference between standards, how the problem is is more important.
To get best performance out of the modern personal computers, Microsoft has developed a new .
Compared with , sharing files is a simpler task.
The boom, predicted by many, has not happened mainly due to problems of .
DOS allows up to to be used for its file names.
When letting computers share files, NFS works better with of computers than with personal computers.
Building reliable programmes takes longer time than reliable standards.
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Question Focus: Synonym match - summary refers to computer data, passage explains what data consists of
Correct Answer: strings of
Why this is correct: The passage clearly explains that computer data is made up of strings of Os and Is. The summary shortens this idea, but the exact words strings of must be copied from the passage.
Passage Reference: Most of the basic problems of sending the strings of Os and Is that make up computer data
Common Mistake: Students may write data or numbers, but these are not the exact words used in the passage. You must copy the exact phrase. This is a synonym trap.
Paraphrasing: Passage: 'strings of Os and Is' = Summary: 'computer data consists of ___ Os and Is'
Tips: When the gap is part of a fixed phrase, copy the phrase exactly as it appears in the passage.
Key Vocabulary:
- string = sequence
- data = information
Question Focus: Synonym match - summary talks about connecting computers
Correct Answer: networking
Passage Reference: Standards are the key to successful networking.
Why this is correct: The passage says standards are essential for successful networking. The summary paraphrases this idea, so the correct word to fill the gap is networking.
Common Mistake: Students sometimes write networks, but the passage uses networking as the activity. This is a grammar trap.
Paraphrasing: Passage: 'successful networking' = Summary: 'the success of ___ depends on standards'
Tips: Check if the gap needs an activity noun ending in -ing, not a plural noun.
Key Vocabulary:
- standard = agreed rule
- networking = connecting computers
Question Focus: Direct phrase match - summary refers to a simple step in network evolution
Correct Answer: share files
Passage Reference: look at what ought to be a fairly simple step in the evolution of computer networks: the ability to share files between machines.
Why this is correct: The passage describes file sharing as a key step, using the exact words share files. The summary uses the same idea, so these words must be copied.
Common Mistake: Writing sharing files changes the grammar and does not match the passage exactly. This is a grammar trap.
Paraphrasing: Passage: 'the ability to share files' = Summary: 'the ability to ___ between machines'
Tips: Always match the verb form exactly. Infinitives usually need the base verb.
Key Vocabulary:
- evolution = development
- file = stored data
Question Focus: Synonym match - summary describes how standards differ
Correct Answer: set
Passage Reference: The differences between them lie not so much in how they solve the problem, but in how they set it.
Why this is correct: The passage explains that standards differ in how they set the problem. The summary shortens this idea, so set is the correct word.
Common Mistake: Students may write solve, but the passage contrasts solving with setting the problem. This is a paraphrase trap.
Paraphrasing: Passage: 'how they set it' = Summary: 'how the problem is ___'
Tips: Be careful with verbs that do not change form in past tense, like set and put.
Key Vocabulary:
- set = define
- difference = way something is not the same
Question Focus: Definition match - summary asks what Unix and DOS are
Correct Answer: operating system
Passage Reference: These use the Unix operating system which does lots of things that Microsoft's DOS (the most popular operating systems for personal computers) docs not.
Why this is correct: The passage clearly identifies Unix and DOS as an operating system. The summary asks for this category, so the exact term is needed.
Common Mistake: Students may write software, which is too general. This is a partial truth trap.
Paraphrasing: Passage: 'Unix operating system' = Summary: 'Unix is an ___'
Tips: If the summary asks what something is, look for a clear definition sentence in the passage.
Key Vocabulary:
- operate = run
- system = organised set
Question Focus: Direct phrase match - summary refers to more complex network problems
Correct Answer: sharing work
Passage Reference: such as getting computers to share work.
Why this is correct: The passage mentions more complex problems like computers sharing work. The summary uses the same idea, so these words fit exactly.
Common Mistake: Students may write working together, but that is not the passage wording. This is a synonym trap.
Paraphrasing: Passage: 'getting computers to share work' = Summary: 'problems such as ___'
Tips: When the passage uses a clear verb phrase, reuse it instead of inventing a synonym.
Key Vocabulary:
- bewildering = confusing
- share = use together
Question Focus: Direct match - summary refers to agreed rules
Correct Answer: standards
Passage Reference: Standards are the key to successful networking. If they arc to communicate, computers must all speak the same language. Everything from how to establish a connection over the telephone to how to detect and correct errors must be agreed in detail at the outset.
Why this is correct: The passage strongly emphasises standards as essential for networks to work. The summary repeats this central idea.
Common Mistake: Writing rules changes the wording and is not allowed. This is a synonym trap.
Paraphrasing: Passage: 'Standards are the key' = Summary: '___ are essential'
Tips: Central ideas are often repeated. Use the exact keyword from the passage.
Key Vocabulary:
- key = essential
- standard = agreed method
Question Focus: Specific detail - limitation of file names
Correct Answer: 12 characters
Passage Reference: Most personal-computer file names, for example, can be only 12 characters long.
Why this is correct: The passage gives a precise figure, saying file names can be only 12 characters long. Numbers are often tested in summaries.
Common Mistake: Students sometimes write short or limited, which misses the exact detail. This is a partial truth trap.
Paraphrasing: Passage: 'can be only 12 characters long' = Summary: 'are limited to ___'
Tips: Always copy numbers exactly. Do not change them into vague descriptions.
Key Vocabulary:
- character = letter or symbol
- limit = maximum
Question Focus: Synonym match - summary refers to computers that are not the same
Correct Answer: different types
Passage Reference: swapping files between different types of computers.
Why this is correct: The passage explains NFS works between different types of computers. The summary shortens this phrase, so different types fits.
Common Mistake: Writing many computers changes the meaning. This is a paraphrase trap.
Paraphrasing: Passage: 'different types of computers' = Summary: 'computers of ___'
Tips: If the passage uses an adjective plus noun, you can often drop the noun in the summary gap.
Key Vocabulary:
- type = kind
- swap = exchange
Question Focus: Process description - summary refers to creating standards
Correct Answer: devising
Passage Reference: Devising flexible, reliable standards takes time
Why this is correct: The passage says devising standards takes time. The summary shortens the sentence, so devising alone is enough.
Common Mistake: Students may write creating, but that word is not in the passage. This is a synonym trap.
Paraphrasing: Passage: 'Devising flexible, reliable standards takes time' = Summary: '___ standards takes time'
Tips: Gerund forms ending in -ing are often tested. Copy them exactly.
Key Vocabulary:
- devise = create
- reliable = dependable
General Tips:
- Summary completion questions follow passage order. Use the previous answer to find the next one quickly.
- Always copy the exact word or words from the passage. Synonyms are not accepted.
- Check grammar around the gap. Articles, prepositions, and verb forms give strong clues.
- Watch numbers and technical terms carefully. These are common test points.
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