TECHNO LEARN

PayBox

2010-11-15T22:06:00.000-08:00

E-BUSINESS MODEL

2010-10-03T22:58:00.000-07:00

It is always interesting to talk about e-business. This innovative way is very amazing. A person can sell his product all around the world by clicking and vice versa. A person can buy a product from another side of earth by clicking the mouse.

E-business is not only selling and buying. There various kind of e-business. Here i will tell you about e-business model (Timmer).

There are 11 e-business model :
1. e-shops
2. e-procurement
3. e-malls
4. e-auction
5. virtual communities
6. collaboration platform service
7. third party marketplace
8. value-chain integrator
9. value-chain service provider
10. information service brokerage
11. trust and other third-party

I think all of you can guess the definition of point 1 to 4. Therefore, i will not tell you the definition in detail.
Probably you will ask, what is the difference between e-shops and e-malls? e-mall is a group of e-shops, while e-shop is "stand alone" online shop.

Now i will let you know the definition of point 5 to 11...

Virtual Communities
focus on added value of communication between members
Collaboration Platform Service
e.g. collaborative design
Third Party Marketplace
common marketing front-end and transaction support to multiple businesses
Value-Chain Integrator
added value by integrating multiple steps of the value chain
Value-Chain Service Provider
support part of value chain, e.g. logistics, payments
Information Service Brokerage
trust providers, business information and consultancy

After reading this article, i hope your knowledge about e-busines broadens. Now, you can choose which e-business will you take. God Speed!!

Business Transformation in Digital Economy

2010-10-03T20:20:00.000-07:00

Hi .. long time no post...
My blog was hybernate for a periode
Now my spirit to write rise again ... :)

Now i want to share you information about Business Transformation in Digital Economy. As you know very well, nowadays digital lifestyle is begin to emerge. The internet both fixed and mobile change the way people to communicate and run their life. Economy and business are influenced as well. Economy Now, i hear a new term n business world DIGITAL ECONOMY. Internet change economy from physical economy to digital economy.

Here are the differences between physical economy and digital economy :

VNC (Virtual Network Computing)

2009-11-22T22:46:00.000-08:00

VNC is software that is used for remote desktop application. An engineer from JDSU introduced me to VNC. We can use VNC to control another desktop. It is very simple, just connect your desktop and remote desktop with cross cable and play your VNC. In VNC application you just need to fill IP address, Subnet, and DNS of your remote desktop. After that... you can control your remote desktop easily.

To install VNC it is very easy as well. It has its free edition.

I use VNC to control Optical DWDM Analyzer. I use JDSU. It is a kind of Optical spectrum analyzer that is specially designed for DWDM measurement. We an use USB memory stick to copy measurement result and process it in our desktop. But... it is very risky. Why? USB memory stick is potential to spead virus to our analyzer. So, i prefer to use VNC to display the result and capture the result by "print screen-ing" it.

About "print screen-ing" i will talk later. It uses a special software : SNAGIT.

Buy Gold Now for Your Future!

2009-11-16T19:05:00.000-08:00

What poor man do if he get a million dollar? He will spend his money for electronic equipment, new car, vacation, and think hard how to spend his money.

What rich man do if he get a million dollar? He will think the way to "reproduce" the money. He never think to spend his money except for his primary and secondary needs. What in his mind is investation!!!

I hope you get the point of my explanation above. Rich man thinks how to get more money from small amount of money. The answer is investation. The real rich man will invest his money into gold. He will buy gold coin or buy gold bullion. The one who buy gold coin is one who loves about art. For the one who don't care about art, he will purchase gold bullion. For him, the most important thing is the value of the gold. Art is not important. Either buy gold coin or buy bullion
is better than buying jewelery. Why? Although they are the same gold, you must pay more for production cost of jewelery. Another weakness of jewelery is selling price is lower than buying price. In the other word you will loss some money when you sell your jewelery.

So.. what are you waiting for. Buy gold coin , buy gold bullion now! For a better future!

Online Course in ITU Academy

2009-06-28T22:29:00.000-07:00

Now you can join varIous online course about telecommunication in :

http://academy.itu.int/

To enroll the course you must obtain enrollment key. How to get enrollment key?
ITU usually invites particular enterprise or government institution to join the course. It gives enrollment key to the ones which are invited.

Direct TV

2009-06-15T08:49:00.000-07:00

DirecTV provides television and audio services to subscribers through satellite transmissions. Services include the equivalent of many local television stations, broadcast television networks, subscription television services, satellite radio services, and private video services. Subscribers have access to dozens or hundreds of channels, so its competitors are cable television service and other satellite-based services

Consumers who purchased DirecTV equipment subscribe to various packages of DirecTV programming for which the subscriber pays a monthly fee. A subscriber also can order pay-per-view events and movies. DirecTV contracts with and pays program providers such as cable networks, motion picture distributors, sports leagues, event promoters, and other programming rights holders, for the right to distribute their programming to its subscribers. All programming distributed by DirecTV is delivered to its broadcast centers in Castle Rock, Colorado, and Los Angeles, California, where it is then digitized and compressed. The resulting signal is encrypted, or electronically scrambled, by DirecTV to prevent its unauthorized reception. DirecTV then transmits these signals to several satellites located in stationary orbit approximately 22,300 miles above the equator

Blue Screen

2009-06-04T00:35:00.000-07:00

Yesterday, i've got my laptop underwent 'blue screen'
Anybody knows what it is?

Let u s check the answer. I took this from wikipedia :

The Blue Screen of Death (also known as a stop error, BSoD, bluescreen, or Blue Screen of Doom) is a colloquialism used for the error screen displayed by some operating systems, most notably Microsoft Windows, after encountering a critical system error which can cause the system to shut down to prevent damage.

Bluescreens on NT-based Windows systems are usually caused by poorly-written device drivers or malfunctioning hardware. In the Win9x era, incompatible DLLs or bugs in the kernel of the operating system could also cause bluescreens. They can also be caused by physical faults such as faulty memory, power supplies, overheating of computer components, or hardware running beyond its specification limits. Bluescreens have been present in all Windows-based operating systems since Windows 3.1; earlier, OS/2 suffered the Black Screen of Death, and early builds of Windows Vista displayed the Red Screen of Death after a boot loader error.

Understanding Mac Address Flooding

2009-05-11T00:31:00.000-07:00

In a typical MAC flooding attack, a switch is flooded with packets, each containing different source MAC addresses. The intention is to consume the limited memory set aside in the switch to store the MAC address-to-physical port translation table.

The result of this attack causes the switch to enter a state called failopen mode, in which all incoming packets are broadcast out on all ports (as with a hub), instead of just down the correct port as per normal operation. A malicious user could then use a packet sniffer running in promiscuous mode to capture sensitive data from other computers, which would not be accessible were the switch operating normally.

Cisco gives you an opportunity to set up protection against this attack with limiting and/or hardwiring some MAC addresses to a dedicated port.

Understand the MAC flooding attack
Suppose to have a switch with 3 PC: PC A, PC B and PC C; in normal situation, when PC A sends a packet to PC B, PC C does not view packet sent between PC A and PC B.

This because the 3 PC are connected to a switch and NOT to a hub.

Under MAC flooding attack, the switch behaviour is different. During the MAC flooding attack, the attacker (in this instance PC C) floods the switch with packets, each with different source MAC address.

If the Content Addressable Memory (the memory where the MAC addresses are stored) is full, the switch works like an hub; so, if the PC A sends a packet to PC B, the packet will be received to PC C too.

802.1x

2009-05-10T21:07:00.000-07:00

What is 802.1x?

"Port-based network access control makes use of the physical access characteristics of IEEE 802 LAN infrastructures in order to provide a means of authenticating and authorizing devices attached to a LAN port that has point-to-point connection characteristics, and of preventing access to that port in cases which the authentication and authorization fails. A port in this context is a single point of attachment to the LAN infrastructure." --- 802.1X-2001, page 1.

Figure 802.1X: A wireless node must be authenticated before it can gain access to other LAN resources

When a new wireless node (WN) requests access to a LAN resource, the access point (AP) asks for the WN's identity. No other traffic than EAP is allowed before the WN is authenticated (the "port" is closed).
The wireless node that requests authentication is often called Supplicant, although it is more correct to say that the wireless node contains a Supplicant. The Supplicant is responsible for responding to Authenticator data that will establish its credentials. The same goes for the access point; the Authenticator is not the access point. Rather, the access point contains an Authenticator. The Authenticator does not even need to be in the access point; it can be an external component.
EAP, which is the protocol used for authentication, was originally used for dial-up PPP. The identity was the username, and either PAP or CHAP authentication [RFC1994] was used to check the user's password. Since the identity is sent in clear (not encrypted), a malicious sniffer may learn the user's identity. "Identity hiding" is therefore used; the real identity is not sent before the encrypted TLS tunnel is up.
After the identity has been sent, the authentication process begins. The protocol used between the Supplicant and the Authenticator is EAP, or, more correctly, EAP encapsulation over LAN (EAPOL). The Authenticator re-encapsulates the EAP messages to RADIUS format, and passes them to the Authentication Server.
During authentication, the Authenticator just relays packets between the Supplicant and the Authentication Server. When the authentication process finishes, the Authentication Server sends a success message (or failure, if the authentication failed). The Authenticator then opens the "port" for the Supplicant.
After a successful authentication, the Supplicant is granted access to other LAN resources/Internet.

Sumber : http://tldp.org/HOWTO/html_single/8021X-HOWTO/

MULTICAST TESTING USING SMART WINDOW

2009-05-01T02:45:00.000-07:00

Hurray... I am happy today...
Finally i find a way to test Multicast service in IP network using Smart Window. :)
I found this way by my self!
Well... to understand how to use Smart Bits Application, such as Smart Window, we need to read the direction in help. Read it carefully, then you will find a light ho to operate Smart Bits for your IP device testing.

I want to tell you the detail about this. But not now. I will tell you later. Please be patient. I am planning to write a legal work instruction for multicast testing using Smart Window. I hope this document will be usefull for somebody else who will test multicast using Smart Window.

Page Rank

2009-04-30T00:54:00.000-07:00

barusan nge check page rank blog ini...
Menyedihkan banget dong.
Masa page rank nya -1
T_T
Bukannya page rank terkecil itu 0 ??

INTERNETWORKING TECHNOLOGY HANDBOOK

2009-04-27T22:31:00.000-07:00

DI SINI

Coret2 tentang UU ITE

2009-04-26T19:53:00.000-07:00

ITE = Informasi dan Transaksi Elektronik

Jadi sekarang email, chat dan dokumen2 lain yang didapatkan dari dunia mayabisa menjadi evidence dalam bertransaksi.

Diundangkan 2008. Indonesia termasuk yang cepat mengaplikasikan UU ITE.

PP = presiden --> ngatur keseluruhan
PM = menteri --> ngatur internal departemen

UU ITE ini bisa menjadi anacaman dan peluang. Peluangnya tapi lebih banyak.
UU no 36 thn 99 --> telekomunikasi sudah diliberaralisasi. Kita bisa merambah ke broadcast dan perbankan.
Finnet = perkawinan antara telco dan perbankan
Telco skrg sudah menjadi ancaman bagi perbankan
Misal : e-voucher.
IPTV juga jadi ancaman bagi dunia broadcast. Kita akan mengeluarakan digital TV.

Undang-undang belum detail. Detailnya akan diturunkan di PP, PM, Kepdirjen, Perdirjen.
Untuk numbering ada di kepdirjen.
That's why UU ITE ini sangat strategis.

MATERI UNDANG-UNDANG ITE
Berlaku di indonesia dan di luar indonesia
Berlaku bagi semua orang

IE dan DE menjadi alat bukti yang sah!

Sertifikasi keandalan mirip2 sertifikat halal MUI atau BPOM (kalau di makanan)
Ada badan pengawas badan sertifikasi keandalan

Tanda tangan elektronik memiliki kekuatan hukum dan akibat hukum yang sah
Tanda tangan digital -> berbasis publik key infrastructure atau berbasis biometric

Sertifikasi digital dapat disimpan di smart card.
Penyelenggara sertifikasi elektronik harus berbadan hukum dan berdomisili di Indonesia, kalau asing harus terdaftar di Indonesia.

RE = registration authority
Seperti notaris yang akan mengecek alamat fisik.

Transaksi elektronik harus ada perjanjian elektroniknya. Berlaku untuk publik dan privat.
Transaksi elektronik memiliki syarat : subjektif dan objektif.
Subjektif : kesepakatan, dan kecakapan
Objektif : informasi valid, sebab yang halal.

Untuk lebih jelasnya, bisa baca dokumen UU ITE yang lebih lengkap. =D

Refleksi

2009-04-19T07:59:00.000-07:00

Pijat? jelas bukan lah...
Cuman pingin menuliskan uneg-uneg yang sesaat lagi akan membludak. Hoho...
Capek...
Dengan pekerjaan kantor. Tepatnya cape hate.
Males dan ilang feeling juga.
Apa minta cuti aja ya?
Disorientasi!
Cinta...
Berkumpul dengan orang-orang sholeh
Berbagi cerita dengan orang-orang yang punya idealisme
Duduk di masjid Allah
Baca Alquran
Rasanya ingin selamanya di sana

Jitter For Beginner

2009-04-06T20:29:00.001-07:00

What is jitter? Jitter is, as shown in Figure 1, is “the short-term variations of a signal with respect to its ideal position in time.”

Figure 1. Jitter in Clock Signals

This deviation in a clock’s output transition from its ideal position can negatively impact data transmission quality. In many cases, other signal deviations, like signal skew and coupled noise are combined and labeled as jitter.

Deviation (expressed in ±ps) can occur on either the leading edge or the trailing edge of a signal. Jitter may be induced and coupled onto a clock signal from several different sources and is not uniform over all frequencies.

Excessive jitter can increase the bit error rate (BER) of a communications signal by incorrectly transmitting a data bit stream. In digital systems, jitter can lead to a violation of timing margins, causing circuits to behave improperly. Accurate measurement of jitter is necessary for ensuring the reliability of a system.

Sources of Jitter

Common sources of jitter include:

Internal circuitry of the phase-locked loop (PLL)
Random thermal noise from a crystal
Other resonating devices
Random mechanical noise from crystal vibration
Signal transmitters
Traces and cables
Connectors
Receivers

Beyond these sources, termination dependency, cross talk, reflection, proximity effects, VCC sag, ground bounce, and electromagnetic interference (EMI) from nearby devices and equipment can also increase the amount of jitter in a device.

Reflection and cross-talk frequency-dependent effects may be amplified if an adjacent signal is synchronous and in phase. Aside from noise caused by power supplies and ground, changes in circuit impedance are responsible for most of the jitter in data transmission circuits.

Jitter Components

The two major components of jitter are random jitter, and deterministic jitter.

Random Jitter

The random component in jitter is due to the noise inherent in electrical circuits and typically exhibits a Gaussian distribution. Random jitter (RJ) is due to stochastic sources, such as substrate and power supply. Electrical noise interacts with the slew rate of signals to produce timing errors at the switching points.

RJ is additive as the sum of squares, and follows a bell curve. Since random jitter is not bounded, it is characterized by its standard deviation (rms) value.

Deterministic Jitter

Deterministic jitter (DJ) is data pattern dependant jitter, attributed to a unique source. Sources are generally related to imperfections in the behavior of a device or transmission media but may also be due to power supply noise, cross-talk, or signal modulation.

DJ is linearly additive and always has a specific source. This jitter component has a non-Gaussian probability density function and is always bounded in amplitude. DJ is characterized by its bounded, peak-to-peak, value.

Types of Jitter

There are many different types of jitter. Period jitter, cycle-to-cycle jitter and half-period jitter are described below.

Period Jitter

Period jitter is the change in a clock’s output transition (typically the rising edge) from its ideal position over consecutive clock edges. Period jitter is measured and expressed in time or frequency. Period jitter measurements are used to calculate timing margins in systems, such as tSU and tCO.

Cycle-to-Cycle Jitter

Cycle-to-cycle jitter is the difference in a clock’s period from one cycle to the next. Cycle-to-cycle jitter is the most difficult to measure usually requiring a timing interval analyzer.

As shown in Figure 2, J1 and J2 are the measured jitter values. The maximum value measured over multiple cycles is the maximum cycle-to-cycle jitter.

Figure 2. Cycle-to-Cycle Jitter

Half-Period Jitter

Half-period jitter is the measure of maximum change in a clock’s output transition from its ideal position during one-half period. Figure 3 illustrates half-period jitter.

Half-period jitter impacts DDR transfer applications by reducing capture margins.

Figure 3. Half-Period Jitter

Jitter Specifications

The performance of the PLL is measured using several parameters. Three of the common specifications used to characterize the PLL are jitter generation, tolerance, and transfer.

Jitter Generation

Jitter generation is the measure of the intrinsic jitter produced by the PLL and is measured at its output. Jitter generation is measured by applying a reference signal with no jitter to the input of the PLL, and measuring its output jitter. Jitter generation is usually specified as a peak-to-peak period jitter value.

Jitter Tolerance

Jitter tolerance is a measure of the ability of a PLL to operate properly (i.e., remain in lock in the presence of jitter of various magnitudes at different frequencies) when jitter is applied to its reference. Jitter tolerance is usually specified using an input jitter mask.

Jitter Transfer

Jitter transfer or jitter attenuation refers to the magnitude of jitter at the output of a device for a given amount of jitter at the input of the device. Input jitter is applied at various amplitudes and frequencies, and output jitter is measured with various bandwidth settings. Since intrinsic jitter is always present, jitter attenuation will appear to be lower for low frequency input jitter signals than for high frequency ones. Jitter transfer is typically specified using a bandwidth plot.

References

Lecroy. 2001. Jitter & Timing Analysis Training Presentation.

http://www.altera.com/support/devices/pll_clock/jitter/pll-jitter.html

UdAH tERaGGREgASI

2009-03-27T02:12:00.000-07:00

Learning spot detribelajar udah teraggregasi google...
Alhamdulillah... semoga bisa bermanfaat untuk siapa pun yang membutuhkan informasi yang ada dalam blog ini...
Walaupun blognya cuman copas an dari site lain, semoga bisa memudahkan proses belajar bagi siapapun, terutama untuk saya sendiri :)
Ayo terus belajar..... Jangan pernah berhenti ;)

TRANSMIT CHARACTERISTIC OF 1000BASE-SX SFP

2009-03-27T01:34:00.000-07:00

These items is described on ITU-T standard : 802.3-2005

UNDERSTANDING LAUNCHED OPTICAL POWER WITHOUT INPUT TO TRANSMITTER

2009-03-27T01:16:00.000-07:00

This is term that is used in Passive Optical Network Technology (PON). PON devices consist of : OLT and ONU/ONU. Downstream is direction from OLT to ONU/ONT, while upstream is direction from ONU/ONT to OLT.

Launched optical power without input to transmitter is different from mean launched optical power.

The mean launched power at OLT and ONU/ONT is the average power of a pseudo-random data sequence coupled into the fibre by the transmitter. It is given as a range to allow for some cost optimization and to cover all allowances for operation under standard operating conditions, transmitter connector degradation, measurement tolerances, and ageing effects.

In operating state, the lower figure is the minimum power which shall be provided and the higher one is the power which shall never be exceeded.

NOTE - The measurement of the launched power at the ONU/ONT optical interface shall take into account the bursty nature of the upstream traffic transmitted by the ONU/ONT.

In the upstream direction, the ONU transmitter shall launch no power into the fibre in all slots which are not assigned to that ONU. The ONU shall also launch no power during the Guard time of slots that are assigned to it, with the exception of the last Tx Enable bits which may be used for laser pre bias, and the Tx Disable bits immediately following the assigned cell, during which the output falls to zero. The launched power level during laser pre-bias must be less than 0.1 of the one level.

www.mblast.com/files/companies/89960/Document/gpon_pmd_white_v01.doc

Optical Power Bidget Calculation

2009-03-27T00:36:00.001-07:00

Optical power budget is term used to describe total amount of light energy amplitude available over a certain link path. The budget can be determined by subtracting the Receiver Sensitivity from the Optical Output Power. The optical budget serves as a useful estimation to determine if sufficient optical output power remains on the receiver side of an optical link. The optical power budget also refers to the allocation of available optical power (transmitted into a given fiber by a given source) among various loss-producing mechanisms.

The loss is caused by various factors. Typical losses are caused by fiber attenuation (per km), slice attenuation (per slice), and connector attenuation (per connector pair).

[Suggestions]

1. Power Budget = (Output / Launch Power) - (Receiver Sensitivity)
2. Worse case Optical Power Budget = (Min TX power) - (Max RX sensitivity) - (LED aging factor) - (insertion loss)

We'll use the following values to illustrate:
Min Tx Power = -9.5 dBm
Max Rx Sensitivity = -20 dBm
Estimated LED aging = 1 dB
Estimated Insertion loss = 1 dB

3. Therefore:
Optical Power Budget = (-9.5 dBm) - (-20 dBm)
Maximum Allowable Loss = 10.5 dB

4. Worst case OPB = Power Budget - Total Optical Power Loss =>
10.5 dB - 1dB (for LED aging) - 1dB (for insertion loss) - 1 dB (for per connector pair) - 2dB (safety factor) = 5 dB

5. Worst case distance = {Worst case OPB, in dB} / [Cable Loss, in dB/Km]

The Optical Power Budget is based on a theoretical calculation, and is for reference only. We still strongly recommend that you perform on-site testing to verify the result. On the data sheet, the supported fiber transmission distances are stated on each switch, with fiber port orSFP fiber modules. The customer can select the desired model without performing the power budget calculation.

http://www.moxa.com/support/faq/faq_detail.aspx?f_id=1239

Optical Power Bidget Calculation

2009-03-27T00:36:00.000-07:00

Location: Home >> Support >> Technical FAQs >> Question 1239

Hi! Pleasesign in

Technical FAQs

Question	How do I calculate the Optical Power Budget?
Question Type	Application
Updated	Feb 27,2008
Hits	797
Products	SFP-1G Series, EDS-510A Series, EDS-726 Series, EDS-518A Series, EDS-516A Series, EDS-505A/508A Series, EDS-405A/408A Series, EDS-316 Series, EDS-309 Series, EDS-P308 Series, EDS-305-M12 Series, EDS-305/308 Series, EDS-205/208 Series, ED6008, EDS-405, EDS-50/505, OS5008, EDS-728 Series, PT-7

The loss is caused by various factors. Typical losses are caused by fiber attenuation (per km), slice attenuation (per slice), and connector attenuation (per connector pair).

[Suggestions]

4. Worst case OPB = Power Budget - Total Optical Power Loss =>
10.5 dB - 1dB (for LED aging) - 1dB (for insertion loss) - 1 dB (for per connector pair) - 2dB (safety factor) = 5 dB

5. Worst case distance = {Worst case OPB, in dB} / [Cable Loss, in dB/Km]

Mengenal G.SHDSL

2009-03-23T01:48:00.000-07:00

Type of standard for DSL* capable of speeds of 2.3mbps, or up to 4.6mbps in some cases, for both upload and download speeds. (1)

G.SHDL is the acronym of Giga Single-pair High bit rate Digital Subscriber Line (2)

G.SHDSL is a new international standard for single-pair, high-speed DSL, as defined in the ITU-T Standard G.991.2. Unlike asymmetric DSL, which was designed for residential applications in which more bandwidth is delivered downstream (to the house) than is available upstream (to the Internet), G.SHDSL is symmetrical - offering 2.3M bit/sec in both directions.

This makes G.SHDSL better-suited for business applications, which require higher-speed bandwidth in both directions.

G.SHDSL combines the positive aspects of existing copper-based, high-speed communications with the benefits of increased data rates, longer reach and less noise.

*DSL = Digital line subscriber

(1) http://www.computerhope.com/jargon/g/gshdsl.htm
(2) http://www.acronymdb.com/acronym/G.SHDSL

MLM dan SLM

2009-03-22T22:50:00.000-07:00

Kalau multimode dan singlemode adalah pembagian jenis kabel fiber optik, MLM dan SLM adalah jenis spektrum sinyal optik yang dipancarkan.

MLM = Multi longitudinal mode
SLM = Singe longitudinal mode

Figure 1 - MLM Laser Spectral Output

Figure 2 - SLM Laser Spectral Output

Multi-mode and Single-mode optical fiber

2009-03-22T22:30:00.000-07:00

There are two general categories of optical fiber: single-mode and multimode

Figure 2. Single-Mode and Multimode Fibers

Multi-mode optical fiber (multimode fiber or MM fiber or fibre) is a type of optical fiber mostly used for communication over shorter distances, such as within a building or on a campus. Typical multimode links have data rates of 10 Mbit/s to 10 Gbit/s over link lengths of up to 600 meters—more than sufficient for the majority of premises applications.

Multimode fiber was the first type of fiber to be commercialized. It has a much larger core than single-mode fiber, allowing hundreds of modes of light to propagate through the fiber simultaneously. Additionally, the larger core diameter of multimode fiber facilitates the use of lower-cost optical transmitters (such as light emitting diodes [LEDs] or vertical cavity surface emitting lasers [VCSELs]) and connectors.

Single-mode fiber, on the other hand, has a much smaller core that allows only one mode of light at a time to propagate through the core. While it might appear that multimode fibers have higher capacity, in fact the opposite is true. Singlemode fibers are designed to maintain spatial and spectral integrity of each optical signal over longer distances, allowing more information to be transmitted.

Its tremendous information-carrying capacity and low intrinsic loss have made single-mode fiber the ideal transmission medium for a multitude of applications. Single-mode fiber is typically used for longer-distance and higher-bandwidth applications (see Figure 3). Multimode fiber is used primarily in systems with short transmission distances (under 2 km), such as premises communications, private data networks, and parallel optic applications.

While fiber optic cable itself has become cheaper over time - a equivalent length of copper cable cost less per foot but not in capacity. Fiber optic cable connectors and the equipment needed to install them are still more expensive than their copper counterparts.

Single Mode cable is a single stand (most applications use 2 fibers) of glass fiber with a diameter of 8.3 to 10 microns that has one mode of transmission. Single Mode Fiber with a relatively narrow diameter, through which only one mode will propagate typically 1310 or 1550nm. Carries higher bandwidth than multimode fiber, but requires a light source with a narrow spectral width. Synonyms mono-mode optical fiber, single-mode fiber, single-mode optical waveguide, uni-mode fiber.

Single Modem fiber is used in many applications where data is sent at multi-frequency (WDM Wave-Division-Multiplexing) so only one cable is needed - (single-mode on one single fiber)

Single-mode fiber gives you a higher transmission rate and up to 50 times more distance than multimode, but it also costs more. Single-mode fiber has a much smaller core than multimode. The small core and single light-wave virtually eliminate any distortion that could result from overlapping light pulses, providing the least signal attenuation and the highest transmission speeds of any fiber cable type.

Single-mode optical fiber is an optical fiber in which only the lowest order bound mode can propagate at the wavelength of interest typically 1300 to 1320nm.

jump to single mode fiber page

Multi-Mode cable has a little bit bigger diameter, with a common diameters in the 50-to-100 micron range for the light carry component (in the US the most common size is 62.5um). Most applications in which Multi-mode fiber is used, 2 fibers are used (WDM is not normally used on multi-mode fiber). POF is a newer plastic-based cable which promises performance similar to glass cable on very short runs, but at a lower cost.

Multimode fiber gives you high bandwidth at high speeds (10 to 100MBS - Gigabit to 275m to 2km) over medium distances. Light waves are dispersed into numerous paths, or modes, as they travel through the cable's core typically 850 or 1300nm. Typical multimode fiber core diameters are 50, 62.5, and 100 micrometers. However, in long cable runs (greater than 3000 feet [914.4 meters), multiple paths of light can cause signal distortion at the receiving end, resulting in an unclear and incomplete data transmission so designers now call for single mode fiber in new applications using Gigabit and beyond.

The use of fiber-optics was generally not available until 1970 when Corning Glass Works was able to produce a fiber with a loss of 20 dB/km. It was recognized that optical fiber would be feasible for telecommunication transmission only if glass could be developed so pure that attenuation would be 20dB/km or less. That is, 1% of the light would remain after traveling 1 km. Today's optical fiber attenuation ranges from 0.5dB/km to 1000dB/km depending on the optical fiber used. Attenuation limits are based on intended application.

sumber :

http://www.iec.org/online/tutorials/fiber_optic/topic02.asp

http://en.wikipedia.org/wiki/Multi-mode_fiber

http://www.arcelect.com/fibercable.htm

IP Multicast to MAC Address Mapping

2009-03-22T19:35:00.000-07:00

Map Multicast MAC address to IP Multicast Addresses

In the course of reading through the BSCI authorize self-study guide, I’ve come across a multicast example where the author talks about the concepts behind the multicast IP to MAC address mapping.

In order to achieve the translation between a Layer 3 IP multicast address and Layer 2 multicast MAC address, the low-order 23 bits of the IP address (Layer 3) is mapped into the low-order 23 bits of the MAC address (Layer 2).
The high order 4 bits of the Layer 3 IP address is fixed to 1110 to indicate the Class D address space between 224.0.0.0 through 239.255.255.255
- Ethernet MAC addresses start with 01:00:5E, allowing for a range from 01:00:5E:00:00:00 through 01:00:5E:7F:FF:FF.
With 32 total bits present in an IP address and 4 high order bits of it set at 1110, we are left with 28 bits of unique IP addresses we can use (32 - 4 = 28).
But remember, 23 low-order bits out of the 28 available bits are mapped to the MAC address, giving us 5 remaining bits of overlap.
With the 5 bits of extra overlap, there are 32 (2⁵ = 32) IP multicast address that map to one MAC multicast address.

The problem is, the book does not explain or show how it solved the mapping. So I went about researching how it was done. If you happened to be studying for BSCI, I am referring to the section of the BSCI: Authorized Self-Study Guide, by Teare and Paquet, that starts on page 598 - 600.

The following is an example of how we arrive with those 32 IP addresses that map to a single MAC address:

For reference, use the following conversion chart for converting hex to binary and vice versa

Let’s start by using the example MAC address given in the book :

01:00:5e:0a:00:01

Convert the hexadecimal MAC address 01:00:5e:0a:00:01 to binary
- 0000 0001 : 0000 0000 : 0101 1110 : 0000 1010 : 0000 0000 : 0000 001
- Here’s a breakdown of the conversion bit by bit:
Isolate the 23 low-order binary bits from the converted MAC address:
- 0000 0001 : 0000 0000 : 0101 1110 : 0000 1010 : 0000 0000 : 0000 0001
Take the low order 23 bits from step 2 and plug it into the low-order 23 bits of the IP address (do this in binary):
- 1110 xxxx : x000 1010 : 0000 0000 : 0000 0000
  - 1110 - First 4 high-order bits of the IP address for the multicast address space (224.x.x.x).
  - xxxx x - 5 remaining bits after the 23bits of the IP address is mapped to the MAC address plus the 4 high order bits 1110. This is equal to 32 total IP addresses.
Convert the binary equivalent of the IP addresses to decimal, replacing the x variables with all the values to get all 32 possible IP addresses:
- 1110 0000 : 0000 1010 : 0000 0000 : 0000 0001 = 224.10.0.1
- 1110 0001 : 0000 1010 : 0000 0000 : 0000 0001 = 225.10.0.1
- 1110 0010 : 0000 1010 : 0000 0000 : 0000 0001 = 226.10.0.1
- 1110 0011 : 0000 1010 : 0000 0000 : 0000 0001 = 227.10.0.1
- 1110 0100 : 0000 1010 : 0000 0000 : 0000 0001 = 228.10.0.1
- 1110 0101 : 0000 1010 : 0000 0000 : 0000 0001 = 229.10.0.1
- 1110 0110 : 0000 1010 : 0000 0000 : 0000 0001 = 230.10.0.1
- 1110 0111 : 0000 1010 : 0000 0000 : 0000 0001 = 231.10.0.1
- 1110 1000 : 0000 1010 : 0000 0000 : 0000 0001 = 232.10.0.1
- 1110 1001 : 0000 1010 : 0000 0000 : 0000 0001 = 233.10.0.1
- 1110 1010 : 0000 1010 : 0000 0000 : 0000 0001 = 234.10.0.1
- 1110 1011 : 0000 1010 : 0000 0000 : 0000 0001 = 235.10.0.1
- 1110 1100 : 0000 1010 : 0000 0000 : 0000 0001 = 236.10.0.1
- 1110 1101 : 0000 1010 : 0000 0000 : 0000 0001 = 237.10.0.1
- 1110 1110 : 0000 1010 : 0000 0000 : 0000 0001 = 238.10.0.1
- 1110 1111 : 0000 1010 : 0000 0000 : 0000 0001 = 239.10.0.1
- 1110 0000 : 1000 1010 : 0000 0000 : 0000 0001 = 224.10.0.1
- 1110 0001 : 1000 1010 : 0000 0000 : 0000 0001 = 225.138.0.1
- 1110 0010 : 1000 1010 : 0000 0000 : 0000 0001 = 226.138.0.1
- 1110 0011 : 1000 1010 : 0000 0000 : 0000 0001 = 227.138.0.1
- 1110 0100 : 1000 1010 : 0000 0000 : 0000 0001 = 228.138.0.1
- 1110 0101 : 1000 1010 : 0000 0000 : 0000 0001 = 229.138.0.1
- 1110 0110 : 1000 1010 : 0000 0000 : 0000 0001 = 230.138.0.1
- 1110 0111 : 1000 1010 : 0000 0000 : 0000 0001 = 231.138.0.1
- 1110 1000 : 1000 1010 : 0000 0000 : 0000 0001 = 232.138.0.1
- 1110 1001 : 1000 1010 : 0000 0000 : 0000 0001 = 233.138.0.1
- 1110 1010 : 1000 1010 : 0000 0000 : 0000 0001 = 234.138.0.1
- 1110 1011 : 1000 1010 : 0000 0000 : 0000 0001 = 235.138.0.1
- 1110 1100 : 1000 1010 : 0000 0000 : 0000 0001 = 236.138.0.1
- 1110 1101 : 1000 1010 : 0000 0000 : 0000 0001 = 237.138.0.1
- 1110 1110 : 1000 1010 : 0000 0000 : 0000 0001 = 238.138.0.1
- 1110 1111 : 1000 1010 : 0000 0000 : 0000 0001 = 239.138.0.1
All the 32 IP addresses on step 4 map to MAC address 01:00:5e:0a:00:01

Convert IP Multicast Address to Multicast MAC Address

Conversely, a multicast IP address can be converted to its equivalent MAC address. Once you’ve figured out how to convert from Layer 2 MAC to Layer 3 IP, doing the reverse is easy.

To start, we can pick any address from the 32 IP addresses we converted above. Let’s pick a random one like 227.138.0.1

First convert the address 227.138.0.1 to binary:
- 11100011 : 10001010 : 00000000 : 00000001
- We’re only concerned with the red colored portion which represents the low-order 23bits of the IP address.
- Notice that we are dropping the high order bit of the second octet.
Convert those 23 bits to hexadecimal:
- 0A:00:01
We already know that the first 3-bytes (24 bits) of the MAC address is 01:00:5E. This was established earlier in the article. Simply append the result on step 2 to the first 3-bytes and you have your MAC address:
- 01:00:5E:0A:00:01
- *You can pick any of the 32 Ip addresses we have on the list above and you will always get 01:00:5E:0A:00:01 as your MAC address following the steps just mentioned.

To summarize:

1^st octet - Notice that the first octet is left alone.
2^nd octet - You only need to convert the last 7 bits to hex. The second octet in decimal is 138. But if you drop the highest order bit, it becomes a decimal 10 or hex 0A.
3^rd octet - Convert it directly to hex.
4^th octet - Convert it directly to hex.

taken from : http://routemyworld.com/2009/03/04/ip-multicast-to-mac-address-mapping/

Fakta-fakta seputar PKS

2009-03-22T19:22:00.000-07:00

–COPAS DARI SEBUAH MILIS–

Saya bukan tim sukses PKS apalagi caleg PKS. Saya hanya berharap senayan diisi oleh orang-orang yang tepat. Yang amanah, yang tidak korupsi dan yang berjuang untuk kesejahteraan rakyat.

Jangan tertipu oleh iklan, jangan tertipu oleh janji. Lihatlah faktanya. Tonton berita. Baca koran. Searching google. Kamu akan tahu siapa yang JUJUR dan lebih layak DIPERCAYA. Dan faktanya ada dihadapan kamu saat ini. Saya ringkaskan untuk kamu. Tapi kalau kamu tidak percaya kepada saya dan mau mencari beritanya sendiri itu lebih baik lagi.

Satu lagi yang penting, Saya tidak mengatakan PKS adalah kumpulan malaikat yang tidak pernah salah. Saya hanya mengatakan PKS relatif lebih BERSIH dan lebih PEDULI dibanding parpol lain. Jadi kalo dicari-cari kesalahannya pasti ada juga kesalahan PKS.

Mungkin kamu kagum kepada SBY, JK atau Mega. Tak mengapa karena bahasan kita kali ini bukan mana presiden terbaik tapi mana parpol terbaik. Tapi ini pendapat saya saja, kalau kamu punya pendapat lain ya tidak apa.

TERBUKTI BERSIH

1. PKS mengembalikan gratifikasi 1,9 M (beritanya ada di sini)

Gratifikasi adalah pemberian dalam arti luas, yakni meliputi pemberian uang, barang, rabat (discount), komisi, pinjaman tanpa bunga, tiket perjalanan, fasilitas penginapan, perjalanan wisata, pengobatan cuma-cuma, dan fasilitas lainnya.

Nah menurut pasal 12 B ayat (1) UU No. 31 tahun 1999 jo. UU No. 20 tahun 2001 tentang Pemberantasan Tindak Korupsi, penerimaan gratifikasi tersebut harus dilaporkan kepada KPK dalam jangka waktu 30 hari sejak diterimanya gratifikasi. Nah di bawah ini adalah parpol di DPR yang melaporkan gratifikasi:
- PKS : 1,9 Milyar
- Golkar: 15,8 juta
- PDK : 5 juta
- PKB : 1 juta
- PDIP : 0
- Demokrat : 0
- PAN : 0
- PDS : 0

Sungguh aneh. Jumlah PKS yang tidak sampai 10% bisa mengembalikan 1,9 milyar sedangkan sisanya yang 90% hanya mengembalikan 21,8 juta. Ternyata parpol lain beralasan mereka tidak melaporkan karena mereka tidak menerima gratifikasi, mereka menolak gratifikasi dari awal. Beritanya ada disini. Apa anda percaya? Saya sih tidak.

Fakta anggota legislatif PKS yang mengembalikan gratifikasi ini sempat menjadi buah bibir di media nasional. Di antaranya Suryama yang dibahas kompas dan Suswono yang dibahas detik.com. Beritanya ada di sini dan sini.

2. PKS mengembalikan uang suap

Diantara 50 anggota Komisi IV DPR yang diduga menerima suap terkait alih fungsi hutan di Tanjung Api-Api, Musi Banyuasin, Sumatera Selatan, semua anggota FPKS sudah mengembalikan uang tersebut. Bahkan Uang dikembalikan pada tahun 2006, jauh sebelum kasus tersebut terungkap. Beritanya di sini. Perhatikan bahwa semua fraksi di DPR terlibat kecuali fraksi PKS. Kamu muak? Saya juga.

3. PKS sering menjadi juru kunci terbongkarnya kasus KORUPSI

Diantaranya Jalaluddin Asy Syatibi juru kunci kasus suap Pemerintah Kabupaten (Pemkab) Bintan. Beritanya di sini. Dan Ahmad Zarkasih terkait dugaan korupsi walikota Bengkulu. Beritanya di sini. Bahkan Ahmad Zarkasih malah dimasukkan penjara terkait laporannya.

TERBUKTI PEDULI

Di bawah ini adalah berita yang saya kumpulkan terkait bukti nyata bahwa anggota DPR dari PKS adalah yang lebih PEDULI dan lebih SENSITIF dengan
nasib rakyat.

1. Terkait Gempa di Yogyakarta

Anggota dewan dari PKS tercatat paling banyak menyumbangkan gajinya kepada korban bencana. FPKS mennyumbang 5 genset untuk korban bencana gempa DIY-Jateng (beritanya di sini) dan anggota DPR PKS menyumbang 100 % gaji buat korban Gempa (beritanya di sini).

2. PKS sering tidak mengambil uang yang merupakan haknya

Tercatat anggota DPR PKS menolak dana upah pungut PAD. Beritanya disini. Mereka juga pernah menolak mobil dinas baru. Beritanya di sini. Dan menolak tunjangan BBM 10jt/bulan. Beritanya di sini. Padahal jika diambilpun itu tidak melanggar hukum karena diatur undang-undang namun itulah bukti kalau anggota DPR dari PKS lebih SENSITIF. Hari gini nolak uang?

Selain anggota DPR PKS yang peduli, kader-kader PKS pun selalu terdepan dalam membantu masyarakat. Baik dalam kegiatan sosial kemasyarakatan maupun dalam penanggulangan bencana.

PHOTO-PHOTO AKSI KEMANUSIAAN PKS KLIK DISINI

Berita-berita di bawah ini juga menepis anggapan jika PKS hanya peduli masalah Palestina dan tidak peduli masalah bangsa. Karena kenyataannya aksi
solidaritas Palestina PKS hanya secuil jika di bandingkan aksi solidaritas kepada satu bangsa. Di sini saya berikan faktanya, kamu bisa menilai sendiri.

1. Terkait banjir seluruh Indonesia
-PKS Dirikan 152 Posko Banjir di 5 Wilayah DKI Jakarta
-Cegah Banjir, PKS Jateng Bangun 100 Sumur Resapan
-1.500 Relawan PKS Bantu Korban Banjir di Wilayah Jatim
-Tim Relawan P2B PKS Jakarta, Siaga Banjir
-PKS Dirikan Delapan Posko Bantuan Banjir di Sinjai
-PKS Jateng Evakuasi Korban Tsunami

2. Terkait tsunami Aceh

-PKS Kelola 150 ribu Lebih Pengungsi di Aceh
-PKS Kirim Relawan ke Aceh
-PKS Kirim Relawan Perempuan ke NAD
-PKS Jadi Buah Bibir Masyarakat Medan
-PKS Aceh Tampung Korban Tsunami
-PKS Himpun Rp 11 Milyar Untuk Korban Tsunami Aceh
-The Washington Post : Misi Kemanusiaan PKS Menuai Simpati

3. Terkait gempa Yogyakarta
-Relawan PKS Tewas Tenggelam di Kali Opak, Bantul
-PKS Kirim 1.000 Relawan
-1.000 Relawan PKS Bersihkan Puing Bangunan di Bantul
-PKS Bantu 300 Kantong Darah Untuk Yogya
-Gempa Yogya Sejumlah Parpol Turunkan Relawan
-PKS Buka Dompet Peduli Yogyakarta di Monas
-PKS Buka Posko Bantuan Gempa Yogyakarta
-DPW PKS Jakarta Terapi 150 Anak Korban Gempa Yogya
-Bersihkan Puing Gempa, PKS Jateng Berangkatkan 1.500 Relawan

Kalau kamu anggap masih kurang silahkan buka:
http://adilsejahteradpress.com/category/aktivitas-kemanusiaan. Di sini lebih lengkap beritanya. PKS harus diakui lebih PEDULI dibanding parpol lain.

Learning Spot

2009-03-18T09:35:00.000-07:00

Diniatkan untuk menuliskan apa yang telah dipelajari di universitas kehidupan

TECHNO LEARN

PayBox

E-BUSINESS MODEL

Business Transformation in Digital Economy

VNC (Virtual Network Computing)

Buy Gold Now for Your Future!

Online Course in ITU Academy

Direct TV

Blue Screen

Understanding Mac Address Flooding

802.1x

MULTICAST TESTING USING SMART WINDOW

Page Rank

INTERNETWORKING TECHNOLOGY HANDBOOK

Coret2 tentang UU ITE

Refleksi

Jitter For Beginner

Sources of Jitter

Jitter Components

Random Jitter

Deterministic Jitter

Types of Jitter

Period Jitter

Cycle-to-Cycle Jitter

Half-Period Jitter

Jitter Specifications

Jitter Generation

Jitter Tolerance

Jitter Transfer

References

UdAH tERaGGREgASI

TRANSMIT CHARACTERISTIC OF 1000BASE-SX SFP

UNDERSTANDING LAUNCHED OPTICAL POWER WITHOUT INPUT TO TRANSMITTER

Optical Power Bidget Calculation

Solution

Optical Power Bidget Calculation

Technical FAQs

Solution

Mengenal G.SHDSL

MLM dan SLM

Multi-mode and Single-mode optical fiber

IP Multicast to MAC Address Mapping

Map Multicast MAC address to IP Multicast Addresses

01:00:5e:0a:00:01

Convert IP Multicast Address to Multicast MAC Address

Fakta-fakta seputar PKS

PHOTO-PHOTO AKSI KEMANUSIAAN PKS KLIK DISINI

Learning Spot