10-Gigabit Ethernet, being standardized in IEEE 802.3a, is a

developing telecommunication technology that offers data speeds

up to 10 billion bits per second. Built on the Ethernet technology

used in most of today's local area networks (LANs), 10-Gigabit

Ethernet is described as a "disruptive" technology that offers a

more efficient and less expensive approach to moving data on

backbone connections between networks while also providing a

consistent technology end-to-end. Using optical fiber, 10-Gigabit

Ethernet can replace existing networks that use ATM switches and

SONET multiplexers on an OC-48 SONET ring with a simpler network

of 10-Gigabit Ethernet switches and at the same time improve the

data rate from 2.5 Gbps to 10 Gbps.

10-Gigabit Ethernet is expected to be used to interconnect local

area networks (LANs), wide area networks (WANs), and metropolitan

area networks (MANs). 10-Gigabit Ethernet uses the familiar IEEE

802.3 Ethernet media access control (MAC) protocol and its frame

format and size. Like Fast Ethernet and Gigabit Ethernet, 10-Gigabit

Ethernet uses full-duplex transmission, which makes possible a

considerable distance range. On multimode fiber, 10-Gigabit Ethernet

will support distances up to 300 meters; on single mode fiber, it

will support distances up to 40 kilometers. Smaller Gigabit Ethernet

networks can feed into a 10-Gigabit Ethernet network.

Accelerated Hub Architecture (AHA) (also called Intel Hub Architecture) is an Intel 800-series chipset design that uses a dedicated bus to transfer data between the two main processor chips instead of using the Peripheral Component Interconnect (PCI) bus, which was used in previous chipset architectures. The Accelerated Hub Architecture provides twice the bandwidth of the traditional PCI bus architecture at 266 MB per second. The Accelerated Hub Architecture consists of a memory controller hub and an input/output (I/O) controller hub (a controller directs or manages access to devices).

The memory controller hub provides the central processing unit (CPU) interface, the memory interface, and the accelerated graphics port (AGP) interface. The memory controller hub supports single or dual processors with up to 1 GB of memory. The memory controller hub also allows for simultaneous processing, which enables more life-like audio and video capabilities.

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ARIN (American Registry of Internet Numbers) is the organization

in the U.S. that manages IP address numbers for the U.S. and

assigned territories. Because Internet addresses must be unique

and because address space on the Internet is limited, there is a

need for some organization to control and allocate address number

blocks. IP number management was formerly a responsibility of the

Internet Assigned Numbers Authority (Internet Assigned Numbers

Authority), which contracted with Network Solutions Inc. for the

actual services. In December 1997, IANA turned this responsibility

over to ARIN, which, along with Reseaux IP Europeens (RIPE) and Asia

Pacific Network Information Center (APNIC), now manages the world's

Internet address assignment and allocation. Domain name management

is still the separate responsibility of Network Solutions and a

number of other registrars accredited by the Internet Corporation

for Assigned Names and Numbers (Internet Corporation for Assigned

Names and Numbers).

For Internet Protocol Version 6 (IPv6), which extends the length of

an Internet address from 32 bits to 128 bits, ARIN will have many

more addresses to manage and allocate.

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Distributed InterNet Applications Architecture

Now referred to as its "Web solution platform," DNA (Distributed

interNet Applications Architecture) was the original name for

Microsoft's strategy to combine its own application-building and

serving technologies with Web protocols.  DNA makes it possible

for a company to build applications that take advantage of both

the Windows platform and the distributed application and data

possibilities of the Internet. In Microsoft's view, users and

companies want both the capabilities of the Windows interface and

applications on their personal computer and the ability to locate

and use other applications and data on the Internet.

Microsoft's Web solution platform is a framework for fitting Windows

and the PC into the 3-tier application concept in which presentation

and local applications and data are performed on the PC while

business processing and database management take place at other

places in a network.

In addition to the Windows operating system and the Internet Explorer

browser, Microsoft identifies these concepts, services, and products

as part of its Web solution platform:

* The Component Object Model (Component Object Model), including both:

      o Microsoft's own COM and related technologies

      o Industry specifications based on COM

* Presentation Services (the mechanics of managing the user interface)

   including:

      o HTML and Dynamic HTML (dynamic HTML)

      o script

      o Components (such as windows, icons, task bars, and so forth)

      o Win32

* Application Services

      o The Internet Information Server (Internet Information Server,

         the Windows NT Web server)

      o Microsoft Message Queue Server (MSMQ)

      o Microsoft Transaction Server (Microsoft Transaction Server)

* Data Access Services

      o Universal Data Access (Universal Data Access)

      o ActiveX Data Objects (ActiveX Data Objects)

      o Object Linking and Embedding DB

* Windows System Services

      o Directory

      o Security

      o Management

      o Networking and Communications

* Other Tools

      o VisualStudio (a visual programming interface)

      o FrontPage (a WYSIWYG Web page building tool)

      o Microsoft BackOffice

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Knowledge Management is the name of a concept in which an enterprise

consciously and comprehensively gathers, organizes, shares, and

analyzes its knowledge in terms of resources, documents, and people

skills. In early 1998, it was believed that few enterprises actually

had a comprehensive knowledge management practice (by any name) in

operation. Advances in technology have changed the way we access and

share information and now many enterprises have some kind

of knowledge management framework in place.

Knowledge management involves data mining and some method of operation

to push information to users. Some vendors are offering products to

help an enterprise inventory and access knowledge resources. The Lotus

Knowledge Discovery System, for example, advertises that it can locate

and organize relevant content and expertise required to address

specific business tasks and projects. It will analyze the relationships

between content, people, topics, and activity, and produce a knowledge

map report, based on a point system, that can be shared.

This process includes:

Gathering

* Data entry

* OCR and scanning

* Voice input

* Pulling information from various sources

* Searching for information to include

Organizing

* Cataloging

* Indexing

* Filtering

* Linking

Refining

* Contextualizing

* Collaborating

* Compacting

* Projecting

* Mining

Disseminating

* Flow

* Sharing

* Alert

* Push

A knowledge management plan involves a survey of corporate goals

and a close examination of the tools, both traditional and technical,

that are required for addressing the needs of the company. The

challenge is to select or build software that fits the context of the

overall plan and encourage employees to share information.

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Lambda Switching (sometimes called photonic switching, or wavelength

switching) is the technology used in optical networking to switch

individual wavelengths of light onto separate paths for specific

routing of information. In conjunction with technologies such as

dense wavelength division multiplexing (DWDM) - which enables 80

or more separate light wavelengths to be transmitted on a single

optical fiber - lambda switching enables a light path to behave

like a virtual circuit.

Although the ability to redirect specific wavelengths intelligently

is, in itself, a technological breakthrough, lambda switching works

in much the same way as traditional routing and switching. Lambda

routers - which are also called wavelength routers, or optical

cross-connects (OXC) - are positioned at network junction points.

The lambda router takes in a single wavelength of light from a

specific fiber optic strand and recombines it into another strand

that is set on a different path. Lambda routers are being

manufactured by a number of companies, including Ciena, Lucent,

and Nortel.

Multiprotocol Lambda Switching is a variation of Multiprotocol Label

Switching (MPLS, confusingly, the abbreviation for both variants)

in which specific wavelengths serve in place of labels as unique

identifiers. The specified wavelengths, like the labels, make it

possible for routers and switches to perform necessary functions

automatically, without having to extract instructions regarding

those functions from IP addresses or other packet information.

Lambda switching gets its name from lambda, the 11th letter of the

Greek alphabet, which has been adopted as the symbol for wavelength.

In networking, the word is used to refer to an individual optical

wavelength.

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Layer Two Tunneling Protocol (L2TP) is an extension of the

Point-to-Point Tunneling Protocol (PPTP) used by an Internet

service provider (ISP) to enable the operation of a virtual

private network (VPN) over the Internet. L2TP merges the best

features of two other tunneling protocols: PPTP from Microsoft

and L2F from Cisco Systems. The two main components that make

up L2TP are the L2TP Access Concentrator (LAC), which is the

device that physically terminates a call and the L2TP Network

Server (LNS), which is the device that terminates and possibly

authenticates the PPP stream.

PPP defines a means of encapsulation to transmit multi-protocol

packets over layer two (L2) point-to-point links. Generally, a

user connects to a network access server (NAS) through ISDN,

ADSL, dialup POTS or other service and runs PPP over that

connection. In this configuration, the L2 and PPP session

endpoints are both on the same NAS.

L2TP uses packet-switched network connections to make it possible

for the endpoints to be located on different machines. The user

has an L2 connection to an access concentrator, which then

tunnels individual PPP frames to the NAS, so that the packets can

be processed separately from the location of the circuit termination.

This means that the connection can terminate at a local circuit

concentrator, eliminating possible long-distance charges, among

other benefits. From the user's point of view, there is no

difference in the operation.

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Microchip Art is a microscopic non-functioning drawing impressed

on the surface of the design mask used in the production of microchips.

The art, which grew out of the tradition of having chip designers

"sign" their work, is created by etching into the upper metallic

layers of the chip in an unused corner of the chip mask. The

existence of microchip art was not widely known until 1998 when

photographer Michal Davidson accidently stumbled on an example

of microchip art while photographing the geometric patterns of

a microchip. Davidson, who makes his living photographing ordinary

objects under a high-power Nikon optical mircroscope, was surprised

to find the children's book character "Waldo" hiding among the

thousands of square microns of circuitry he was looking at. (The

objective of the "Where's Waldo?" books is for children to find

the Waldo character who is hidden somewhere in each page's

illustration.) Davidson, who at first thought the image was a

fluke, began to closely examine other microchips under his microscope

and found what writer Michael Stroh has described as "the Lascaux

Cave of the computer industry".

Since his initial discovery, Davidson has found and photographed a

wide variety of examples of microchip art, including intricate

sketches of hummingbirds, locomotives, and buffalo. After posting

his microphotographs on a Web site, Davidson was pleased to have many

of the chip designers contact him about their work and explain the

symbolism behind the chosen design. For example, a bulldozer that

appears on a chip designed in 1980 by Synertek was a mystery until

it was learned that the chip was used in heavy equipment electonic

monitoring systems.

Microchip art is frowned upon in some corporations, noteably Intel,

because the software used to create chips is programmed to spot design

flaws, and, as microchips become more complex, the possibility exists

that poorly executed microchip art could pose production problems.

Chip designers, however, compare microchip art to the "Easter eggs"

that programmers leave behind, and promise that somehow creative

minds will continue to "make their mark" upon their work

Network Information Service

What's the easiest way to administer your UNIX network? One of them is

to use the NIS, discussed in this tip from TCP/IP Network

The Network Information Service (NIS) is an administrative database

that provides central control and automatic dissemination of important

administrative files. NIS converts several standard UNIX files into

databases that can be queried over the network. The databases are

called NIS Maps. Some maps are created from files that you're familiar

with from system administration, such as the password file

(/etc/passwd) and the groups file (/etc/group). Others are derived from

files related to network administration.

/etc/ethers

Creates the NIS maps ethers.byaddr and ethers.byname. The /etc/ethers

file is used by RARP.

/etc/hosts

Produces the maps hosts.byname and hosts.byaddr.

/etc/networks

Produces the maps networks.byname and networks.byaddr.

/etc/services

Produces a single map called services.byname.

/etc/aliases

Defines electronic mail aliases and produces the maps mail.aliases and

mail.byaddr.

Check the maps available on your server with the ypcat - x command.

The advantage of using NIS is that these important administrative

files can be maintained on a central server, and yet completely

accessible to every workstation on the network. All of the maps are

stored on a master server that runs the NIS server process ypserv. The

maps are queried remotely by client systems. Clients run ypbind to

locate the server.

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RAID

RAID (redundant array of independent disks) is a way of storing the

same data in different places (thus, redundantly) on multiple hard

disk. By placing data on multiple disks, I/O operations can overlap

in a balanced way, improving performance. Since multiple disks

increases the mean time between failure (MTBF), storing data

redundantly also increases fault-tolerance.

A RAID appears to the operating system to be a single logical hard

disk. RAID employs the technique of striping, which involves

partitioning each drive's storage space into units ranging from

a sector (512 bytes) up to several megabytes. The stripes of all

the disks are interleaved and addressed in order.

In a single-user system where large records, such as medical or

other scientific images, are stored, the stripes are typically set

up to be small (perhaps 512 bytes) so that a single record spans

all disks and can be accessed quickly by reading all disks at the

same time.

In a multi-user system, better performance requires establishing a

stripe wide enough to hold the typical or maximum size record. This

allows overlapped disk I/O across drives.

There are at least nine types of RAID plus a non-redundant array (RAID-0):

* RAID-0. This technique has striping but no redundancy of data. It

  offers the best performance but no fault-tolerance.

* RAID-1. This type is also known as disk mirroring and consists of at

  least two drives that duplicate the storage of data. There is no

  striping. Read performance is improved since either disk can be read

  at the same time. Write performance is the same as for single disk

  storage. RAID-1 provides the best performance and the best

  fault-tolerance in a multi-user system.

* RAID-2. This type uses striping across disks with some disks storing

  error checking and correcting (ECC) information. It has no advantage

  over RAID-3.

* RAID-3. This type uses striping and dedicates one drive to storing

  parity information. The embedded error checking (ECC) information is

  used to detect errors. Data recovery is accomplished by calculating

  the exclusive OR (XOR) of the information recorded on the other drives.

  Since an I/O operation addresses all drives at the same time, RAID-3

  cannot overlap I/O. For this reason, RAID-3 is best for single-user

  systems with long record applications.

* RAID-4. This type uses large stripes, which means you can read records

  from any single drive. This allows you to take advantage of overlapped

  I/O for read operations. Since all write operations have to update the

  parity drive, no I/O overlapping is possible. RAID-4 offers no advantage

  over RAID-5.

* RAID-5. This type includes a rotating parity array, thus addressing the

  write limitation in RAID-4. Thus, all read and write operations can

  be  overlapped. RAID-5 stores parity information but not redundant data

  (but parity information can be used to reconstruct data). RAID-5 requires

  at least three and usually five disks for the array. It's best for multi-

  user systems in which performance is not critical or which do few write

  operations.

* RAID-6. This type is similar to RAID-5 but includes a second parity

  scheme that is distributed across different drives and thus offers

  extremely high fault- and drive-failure tolerance. There are few or

  no commercial examples currently.

* RAID-7. This type includes a real-time embedded operating system as

  a controller, caching via a high-speed bus, and other characteristics

  of a stand-alone computer. One vendor offers this system.

* RAID-10. This type offers an array of stripes in which each stripe is

  a RAID-1 array of drives. This offers higher performance than RAID-1 but

  at much higher cost.

* RAID-53. This type offers an array of stripes in which each stripe is a

  RAID-3 array of disks. This offers higher performance than RAID-3 but at

  much higher cost.

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