IEEE-802.3 Protocol

The IEEE-802.3 Protocol is based on the Xerox Network Standard (XNS) called Ethernet. The IEEE-802.3 Protocol is commonly called Ethernet but it is just one version. These are the four versions of the Ethernet frame:

  • Ethernet_802.2 Frame type used on Netware 3.12 & 4.01
  • Ethernet_802.3 Frame type used on Netware 3.x & 2.x (raw)
  • Ethernet_II Frame type used on DEC, TCP/IP
  • Ethernet_SNAP Frame type used on Appletalk (SubNet Access Protocol)

NOTE: The Source and Destination must have the same Ethernet Frame type in order to communicate.

CSMA / CD (Carrier Sense Multiple Access / Collision Detect)


Bus arbitration is performed on all versions of Ethernet using the CSMA / CD (Carrier Sense Multiple Access / Collision Detect) protocol. Bus arbitration is another way of discussing how to control who is allowed to talk on the medium (and when). Put simply, it is used to determine who’s turn it is to talk.

In CSMA / CD, all stations, on the same segment of cable, listen for the carrier signal. If they hear the carrier, then they know that someone else it talking on the wire. If they don’t hear carrier then they know that they can talk. This is called the Carrier Sense portion of CSMA / CD.

All stations share the same segment of cable, and can talk on it similar to a party line. This is the Multiple Access portion of CSMA / CD.

If 2 stations should attempt to talk at the same time, a collision is detected, and both stations back off–for a random amount of time–before they try again. This is the Collision Detect portion of CSMA/CD.

IEEE 802.3 Ethernet Media Types


The most common Ethernet variants

IEEE 802.3 defines five media types of IEEE 802.3 Ethernet Types shown below:

  • IEEE 802.3 10Base5 Thick Coax 10Mbps Baseband 500m
  • IEEE 802.3a 10Base2 Thin Coax 10Mbps Baseband 185m
  • IEEE803b 10Broad36 Broadband 10 Mbps Broadband 3600m
  • IEEE802.3e 1Base5 StarLAN 1 Mbps Baseband 500m
  • IEEE 802.3i 10BaseT Twisted Pair 10Mps Baseband 100m

IEEE 802.3 – 10Base5 (Thick Coax) is used only as backbones to networks. Backbones are lines that connect buildings & network equipment together (such as Bridges, Routers, Brouter, Hubs, Concentrators, Gateways, etc.). 10Base5 is now being replaced by either Thin Coax or fiber optics.

IEEE 802.3a – 10Base2 is commonly used in new installations as a backbone to connect buildings and network equipment together. 10Base2 (Thin Coax) is also used to connect work stations together, but the preferred choice is to use 10BaseT.

IEEE 802.3b – 10Broad36 is rarely used; it combines analog and digital signals together. Broadband means that a mixture of signals can be sent on the same medium.

IEEE 802.3e – StarLAN is a slow 1 Mbps standard that has been replaced by Thin Coax or Twisted Pair.

IEEE 802.3i – 10BaseT is commonly used to connect workstations to network hubs. The network hubs can use 10BaseT (Twisted Pair) to connect to other Hubs.

IEEE 802.3 10Base5 Thick Coax 10Mbps Baseband 500m


10Base5 Specifications : 

Coaxial Cable

Coaxial cable uses double-shielded 0.4 inch diameter RG8 coaxial cable (about the size of a garden hose). The cable is not flexible, and difficult to work with. The cable has a characteristic impedance of 50 ohms.

Connection to the workstation is made with a MAU Medium Attachment Unit (or Transceiver). The MAU physically and electrically attaches to the coaxial cable by a cable tap. The cable is pierced, and a connection is made (by a screw) to the center conductor.

The MAU is connected to the NIC (Network Interface Card) by the AUI (Attachment Unit Interface) cable. The AUI port on a NIC (and a MAU) is a DB15 connector. Maximum AUI cable length is 50 m.

Cable Termination and Connector

The standard termination is 50 +/-2 ohms. The end connector on the RG-8 cable is an “N” type connector. The cable is externally terminated with a resistor inside an N connector.

Grounding

To minimize noise on the segment, the cable is grounded at the termination–at only one end. 

Maximum Nodes on a cable segment

On any single cable segment, the maximum allowed number of nodes or MAUs is 100.

Minimum Distance between nodes

Minimum distance between nodes, or MAUs, is 2.5 m (or 8 feet).

Velocity of propagation

The speed of the signal through the cable is 0.77c. (“c” is equal to the speed of light – 300,000,000 m/sec). The velocity of propagation for 10Base5 specification cable is equal to 0.77 x 300,000,000 m/sec. This is determined by cable capacitance. Maximum coaxial cable segment length is 500 m.

The maximum segment length is 500 m–or, a maximum 2.165 uSec propagation delay. Propagation delay is what actually determines the maximum length of the segment.

Propagation delay for a specific cable length in meters is calculated by:

What is the propagation delay for a 500 m length of 10Base5 cable?

Maximum Number of Segments

Maximum of 5 segments (with 4 repeaters) can be along the path between any 2 network nodes: 3 may be coax segments having a maximum delay of 2.165 uSec and 2 may be link segments having a maximum delay of 2.570 uSec.

With no link segments used, three populated coax segments can exist on a path.

The 5-4-3 Rule

The 5-4-3 Rule states that you are allowed five (5) segments, with four (4) repeaters, and three (3) populated segments.

Maximum Transfer Rate

The Maximum Data Transfer Rate for IEEE 802.3 is 10 Mbps (10,000,000 bits per second of data). In fact, data transfer is dependent on how many users are fighting for the bus–and how fast the user’s data can get on the bus.

Physical Bus / Logical Bus

IEEE 802.3 is a Physical Bus – the cable is physically laid out as 1 long cable with the network nodes attached to it. It is also treated as a Logical Bus – electronically and logically, it appears as one long cable, with the network nodes attached to it.

IEEE 802.3a 10Base2 Thin Coax 10Mbps Baseband 185m


Coaxial Cable

Uses RG-58A/U coaxial cable, 0.2 inch in diameter. The cable is flexible and easy to work with. The cable has a characteristic impedance of 50 ohms.

Connection to the workstation is made with either a MAU – Medium Attachment Unit / Transceiver, or directly to the NIC using a BNC TEE.

Most NICs have the MAU built-in for 10Base2. The 3C509 card in the lab have built-in MAUs for Coax (10Base2) and Twisted Pair (10BaseT). They also have a AUI connection for an external MAU, such as used in 10Base5. You can buy MAUs for 10Base2 and 10BaseT (if your NIC does not have them already built-in).

Cable Termination and Connector

The standard termination is 50 +/-2 ohms. The end connector is an “BNC” twist and lock-type connector. The cable is externally terminated with a special terminating BNC connector. BNC stands for Bayonet Navy Connector.

Grounding

To minimize noise on the segment, the cable is floating. The IEEE 802.3a specifications calls for all BNC connectors and TEEs to be insulated. A common problem with 10Base2 is having the barrel of the BNC connector touching a heating duct or computer chassis.

The shield should be floating: it is not connected to electrical ground.

Maximum Nodes on a cable segment.

On any 1 cable segment, the maximum allowed number of nodes is 30.

Minimum Distance between Nodes

Minimum distance between nodes is 0.6 m (2 feet).

Velocity of propagation

The speed of the signal through the 10Base2 cable is 0.65c. (“c” is equal to the speed of light – 300,000,000 m/sec). The minimum velocity of propagation for 10Base2 specification cable is equal to 0.65 x 300,000,000 m/sec. This is determined by cable capacitance.

Maximum coaxial cable segment length 185 m.

The maximum segment length is 185 m (600 ft.), or a maximum 0.949 uSec propagation delay. Propagation delay, not distance, is what actually determines the maximum length of the segment. Propagation delay (units are seconds) is calculated by:

What is the propagation delay for a 185 m length of 10Base2 cable?

Maximum Number of Segments

Maximum of 5 segments (with 4 repeaters) can be along the path between any two network nodes: 3 may be coax segments having a maximum delay of 0.949 uSec, and 2 may be link segments having a maximum delay of 0.949 uSec.

With no link segments used, three populated coax segments can exist on a path.

Maximum Transfer Rate

The Maximum Data Transfer Rate for IEEE 802.3a is 10 Mbps (10,000,000 bits per second of data). In actual fact, data transfer is dependent on how many users are fighting for the bus–and how fast the user’s data can get on the bus.

Physical Bus/Logical Bus

IEEE 802.3a is a Physical Bus – the cable is physically laid out as one long cable, with the network nodes attached to it.

It is also treated as a Logical Bus – electronically and logically, it appears as one long cable, with the network nodes attached to it.

IEEE 802.3i 10BaseT Twisted Pair 10Mps Baseband 100m


Twisted Pair Cable

10BaseT uses unshielded twisted pair (UTP) cable. The cable is flexible and easy to work with. The cable has a characteristic impedance of 100 ohms. There are 2 pairs of twisted wires used with 10BaseT: separate Rx (receive) and Tx (transmit) pairs. The lines are balanced lines to minimize noise and there are a Rx+ & Rx- pair and a Tx+ & Tx- pair.

The nodes are connected to a MPR (multi port repeater), also called a Concentrator, or Hub. The cables are wired as straight-through cables: this means that the Node’s Rx & Tx lines connect directly to the Hub’s Rx & Tx lines respectively.

Two nodes can be directly connected together (bypassing the Hub) by using a Cross-over (X-over) cable. In a X-over cable, the Tx and Rx lines are crossed so that one node’s Tx lines go to the other node’s Rx lines–and vice versa.

Cable Termination and Connector

The standard termination is 100 ohms. The end connector is an “RJ45” quick disconnect connector. The cable is internally terminated at the NIC (Network Interface Card) and Hub.

Grounding

To minimize noise on the segment, the cable is a balanced line with Rx- & Rx+ and Tx- & Tx+. There is no shielding: any noise that appears on the Rx+ wire will appear on the Rx- wire. When the 2 signals are combined, the noise cancels because Rx- & Rx+ is 180 degrees out of phase.

Maximum Nodes

For 10BaseT, the maximum allowed number of nodes is 128 (on one segment).

Maximum Distance between Nodes & Hub

The maximum distance between nodes & Hub is 100 m.

Velocity of propagation

The speed of the signal through the cable is 0.59c. (“c” is equal to the speed of light: 300,000,000 m/sec). The minimum velocity of propagation for 10Base5 specification cable is equal to 0.59 x 300,000,000 m/sec., and is determined by cable capacitance.

Maximum cable segment length 100 m

The maximum segment length is 100 m, or a maximum 0.565 uSec propagation delay. Propagation delay, not distance, is what actually determines the maximum length of the segment. Propagation delay (units are seconds) is calculated by the following:

What is the propagation delay for a 100 m length of 10BaseT cable?

Maximum Number of Segments

A maximum of 5 segments (with 4 repeaters) can be along the path that’s between any 2 network nodes: 3 may be coax segments, having a maximum delay of 0.565 uSec, and 2 may be link segments, having a maximum delay of 0.565 uSec. The 5-4-3 rule, and its special implications for IEEE 802.3i., will be discussed under Repeaters

Maximum Transfer Rate

The Maximum Data Transfer Rate for IEEE 802.3i is 10 Mbps (i.e. 10,000,000 bits per second of data). In actual fact, though, data transfer is dependent on how many users are fighting for the bus–and how fast the user’s data can get on the bus.

Physical Star / Logical Bus

IEEE 802.3a is a Physical Star. The cable is physically laid out as star pattern, with all twisted pair cables (AUIs) coming from the nodes to a central wiring closet (containing the Hub, or Multi-Port Repeater / Concentrator).

It is treated as a Logical Bus: electronically and logically, it appears as 1 long cable, with the network nodes attached to it. A node can be a client, a server, a workstation, or other hub.

MAC – Medium Access Control

The IEEE 802.3 Medium Access Control layer is physically located in the firmware (ROM) of the Network Interface Card. It is the link between the Data Link Layer and the Physical Layer of the OSI model, and logically resides in the lower portion of the Data Link Layer. There is only 1 MAC layer for all of the IEEE 802.3 versions (802.3, 802.3a, 802.3b, 802.3i, etc.).

The IEEE 802.3 Medium Access Control uses CSMA/CD (Carrier Sense Multiple Access/Collision Detect) to determine Bus Arbitration. The MAC layer is concerned with the order of the bits, and converting the Datagram from the Network Layer into Packets/Frames.

Preamble

The Preamble is used to synchronize the receiving station’s clock. It consists of 7 bytes (consisting of 10101010 each).

Start Frame Delimiter (SFD)

The Start Frame Delimiter indicates the start of the frame. It consists of 1 byte of 10101011. It is an identical bit pattern to the preamble mentioned above, except for the last bit.

Start Frame Delimiter (SFD)

The Start Frame Delimiter indicates the start of the frame. It consists of 1 byte of 10101011. It is an identical bit pattern to the preamble, except for the last bit.

The Destination Address (DA)

The DA indicates the destination (receiving station) of the frame. It can be 2 or 6 octets long (16 or 48 bits); usually, it is 6 octets (the 2 octet version is used for compatibility with the original Ethernet frame from XNS, and is considered obsolete).

The DA field consists of the following:

I / G stands for Individual/Group. It indicates whether the destination is for an individual or for a multicast broadcast. It is one bit long, as shown below:

0 = Individual1 = Group

A multicast broadcast can be for everyone or for a group. For a multicast broadcast to all stations, the Destination Address = FFFFFFFFFFFFh (h – hexadecimal notation). To multicast to a specific group, unique addresses must be assigned to each station–by the Network Administrator.

U / L stands for Universal/Local. It allows for unique addresses. It is used to indicate whether or not a local naming convention is used, and is administered by the Network Administrator (not recommended – an incredible amount of work). The burnt-in ROM address is also used (and is recommended).

The 46-Bit Address Field consists of 46 bits. This address field indicates the destination NIC card’s address, which is burnt into the firmware (ROM) of the card. It can also be the unique name assigned to the card during the card’s initialization–by the Network Administrator.

Source Address (SA)

The Source Address indicates the source–or transmitting station–of the frame. It is identical in format to the Destination Address, but always has the I/G bit = 0 (Individual/Group Bit = Individual).

Length (L)

The Length field indicates the Length of the Information Field: it allows for variable-length frames. The minimum Information Field size is 46 octets and the maximum size is 1500 octets. When the Information Field size is less than 46 octets, the Pad field is used. Because the 802.3 MAC Frame has a Length field, there is no End Delimiter. The Length of the field is known and the receiving station counts the number of octets.

Information Field (Data)

The Information Field contains the Data from the next upper layer, the Logical Link Control Layer. It is commonly referred to as the LLC Data. The minimum Information Field size is 46 octets and the maximum size is 1500 octets.

Pad

The Pad is used to add octets–to the Information Field–to bring it up to the minimum size of 46 octets (if the Info Field is less than the minimum).

Frame Check Sequence (FCS)

The Frame Check Sequence is used for error-checking at the bit level. It is based on 32 bit CRC (Cyclic Redundancy Checking), and consists of 4 octets (4 x 8 = 32 bits). The FCS is calculated according to the contents of the DA, SA, L, Data and Pad fields.

Total Length of a MAC Frame

Min Size (octets) Max Size (octets)
Preamble 7 7
Start Frame Delimiter 1 1
Destination Address 6 6
Source Address 6 6
Length 2 2
Information Field 46 1500
Frame Check Sequence 4 4
TOTAL: 72 1526 Octets

Packet Sniffing

A packet sniffer captures packets from the Ethernet bus. The network interface card (NIC) acts in a mode called “promiscuous mode.” Promiscuous mode means that the NIC can look at all traffic on the wire, and not just traffic addressed to itself. Normally, the NIC ignores all traffic (except for packets addressed to itself, multicasts and broadcast packets).

The following captured packet is displayed in raw format. Raw format is hexadecimal numbers that are in rows of 16 digits (see below).

FF FF FF FF FF FF 00 20 AF 10 9A C0 00 25 E0 E003 FF FF
00 22 00 11 00 00 00 00 FF FF FF FF FFFF 04 52 00 00 00 00 00 20 AF 10
9A C0 40 0B 0001 00 04 00 00 00 00 00 00 00 00 00

Raw Captured Packet

Raw captured packets do not display the Preamble, Start Frame Delimiter or the Frame Check Sequence fields. These fields are used to inform the receiving station of a new frame, and also for error checking.

The breakdown of the packet (according to the Ethernet MAC frame) is shown below:

1st 6 bytes: FF-FF-FF-FF-FF-FF Destination MAC address
2nd 6 bytes: 00-20-AF-10-9A-C0 Source MAC address
Next 2 bytes: 0025 Length/Type field – IEEE 802.3 frame
Next 37 bytes Data
Last 9 bytes all 00s Pad

The length of the data in the Info field is 0025h, or 37 bytes long. The minimum Info field size is 46 bytes so the data is padded with 9 bytes of 00h.

The Length / Type field value is less than 05DCh (1500 in decimal). This statistic indicates that it is an Ethernet_802.2 frame (IEEE 802.3) that has a Logical Link Control layer (covered later) between the MAC layer and the Network layer.

If the value is 0800h, this indicates an Ethernet_II frame used for TCP/IP.

If the value is 8137, this indicates an Ethernet_802.3 (raw) frame used by pre 3.12 Netware.

The complete listing of the Length/Type field assignments is covered in Appendix C Ethernet Type Field.

Looking at the MAC block diagram, the data from the Info field is shown broken down (up, to be more exact) into the higher levels: Logical Link Control layer, Network layer and Transport layer. Note: A thorough knowledge of each of the layers, and quite a few handy reference books, are required in order to determine exactly what is happening. The remaining layers will be examined as an example only.

Note: Modern packet sniffer will break down the raw packet’s fields for you.

LLC Layer

The first 3 bytes of the data–in the Ethernet frame Info field– is the header of the Logical Link Control layer (LLC IEEE 802.2).

1st byte:E0Destination Service Access Port (DSAP)
2nd byte:E0Source Service Access Port (SSAP)3rd byte:03Control code

E0h indicates that it is a Novell Netware stack talking (source) to a Novell Netware stack (destination). The 03h is the LLC layer’s handshaking. The size of the LLC’s Data field is 34 bytes. The LLC layer is covered extensively in the next chapter (Chapter 34).

Network Layer

The data of the LLC layer becomes both the header and data of the layer above it (the Network layer). In this case, it is an IPX PDU (Protocol Data Unit). This is indicated by the first 2 bytes being FFFFh (the IPX checksum).

(Hex)1st 2 bytes:FFFFIPX Checksum
(always FFFFh, FCS does error checking)Next 2 bytes:0022IPX PDU length
allowable range 001Eh (30) to 0240h (576)Next byte:00Transport control field – hop count,
allowed 00 to 0Fh (15)Next byte:11Packet Type 11h (17) is Netware Core Protocol (NCP)
Next 4 bytes:00000000Destination network address, all 0s indicate local networkSegment number
in server autoexec.ncf fileNext 6 bytes:FFFFFFFFFFFFDestination host address
(same as dest MAC address)Next 2 bytes:0452Destination socket ,
Service Advertising ProtocolNext 4 bytes:00000000Source network address
(all 0s indicate local network)Next 6 bytes:0020AF109AC0Source host address
(same as soruce MAC address)Next 2 bytes:400BSource socket
(arbitrarily assigned starting at 4000h)Last 4 bytes:Data

The following tables describe the field values for the IPX PDU’s packet type and Socket numbers:
Packet TypeField Value PurposeNLSP00hNetware Link Services ProtocolRIP01hRouting Information
Protocol SAP04hService Advertising ProtocolSPX05hSequenced Packet ExchangeNCP11hNetware Core
ProtocolNetBIOS14hNetBIOS and other propagated packets

IPX Packet Type Field

Netware Socket Numbers and Processes

Socket NumberProcess451hNetware Core Protocol (NCP)452hService Advertising Protocol
(SAP)453hRouting Information Protocol (RIP)455hNovell NetBIOS456hDiagnostics9001Netware
Link Services Protocol (NLSP)9004IPXWAN Protocol

Transport Layer

The Network layer’s Data field becomes the Transport layer’s PDU. In this case, it is only 4 bytes long.

1st 2 bytes:0001Packet type (Standard Server Request)
Next 2 bytes:0004Service type (file server)

The following tables describe the values of the Service Advertising Protocol’s Packet Type and Service Type fields:

Field Value (hex)Packet Type01Standard Server Request02Standard
Server Reply03Nearest Server Request04Nearest Server Reply

SAP Packet Types

Field Value (hex)Service Type0000Unknown0003Print Queue0004File
Server0005Job Server0007Print Server0009Archive Server0024Remote Bridge Server0047
Advertising Print Server8000All values are reserved up to 8000FFFFWildcard

Example Packet Sniffing Summary

This packet is commonly called a Standard Server Request. It is broadcast (Destination FF-FF-FF-FF-FF-FF) on the local network (00-00-00-00) f rom a Novell Netware client. The client is looking for a file server to login in to. The server would respond with a Server Advertising Protocol PDU listing its services.

Cisco Certified Network Associate | CCNA

NETWORKING

images

Apa itu CCNA?


Jawab :

CCNA adalah sertifikasi networking pada level dasar (associate) yang diperuntukkan bagi mahasiswa/engineer/umum yang ingin mendalami teknologinya Cisco.

Tidak hanya teknologinya saja yang dipelajari, tapi juga perangkatnya Cisco yaitu Router dan Switch.

CCNA saat ini menjadi requirement bagi engineer yang ingin terjun ke dunia teknologi informasi khususnya networking. Dengan memiliki CCNA, engineer memiliki prospek pekerjaan yang kompetitif untuk kedepannya.

 

CCNA-Syllabus

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cisco-security-training--ccna--ccnp-certification_56cd973d742eb

mengenal-cisca-ccna-21

cisco-career-certifications

ccnaexploration

ccnadiscovery

1 |Bagaimana cara mendapatkan CCNA?


Jawab :

Anda mengikuti ujian sertifikasi (exam) di perwakilan Cisco yaitu Pearson Vue. Di Bandung misalnya Telkom PDC.

Sebelum mengikuti ujian, Anda harus mendaftar dulu. Untuk mengetahui lokasi ujian yang dekat dengan Anda, silahkan klik Locate Test Center.

Pada saat pendaftaran ujian, Anda akan ditanya kode ujiannya (exam code) untuk sertifikasi Cisco CCNA.

CCNA-Training-Certification

2 |Berapa kode ujian untuk CCNA?


Jawab :

Untuk CCNA kode ujiannya 200-120

3 |Berapa biaya ujian untuk CCNA?


Jawab :

Screenshot from 2016-08-23 14-18-26

Untuk CCNA harga ujiannya 295 USD

Biasanya Anda akan dikenai pajak dan biaya administrasi jika mengikuti ujian di perwakilan Pearson Vue. Biaya tersebut berbeda-beda tiap lembaga. Dan harga akhir yang harus dibayarkan tergantung kurs dollar pada saat Anda mendaftarkan diri untuk ujian.

Berdasarkan informasi dari marketing TelkomPDC pada 2 Nov 2015, biaya ujian CCNA 295 USD include administrasi totalnya Rp 4.700.000

4 |Bagaimana cara mendaftar ujian CCNA di lembaga testing center?


Jawab :

Berikut ini beberapa langkah praktis untuk mendaftar ujian CCNA :

  1. Kontak lembaga testing center pilihan Anda. Biasanya 1 atau 2 minggu sebelum waktu pelaksanaan ujian. Carilah yang dekat dengan lokasi Anda tinggal.
  2. Isi formulir pendaftaran ujian, biasanya terdapat kode ujian dan waktu pelaksanaan ujian. Setelah itu kirimkan kembali ke pihak testing center.
  3. Transfer biaya ujian ke lembaga testing center atau datang langsung dengan membayar cash
  4. Datang ke lokasi ujian 30 menit sebelum waktu pelaksanaan ujian
  5. Tips dari nixtrain : pada saat memilih jam ujian, hendaknya pilih yang pagi hari, misal jam 09.00 – 11.00. Karena pada jam ini biasanya belum melakukan aktivitas pekerjaan yang nantinya dapat mengganggu konsentrasi pada saat ujian.

5 |Bagaimana cara belajar untuk mendapatkan CCNA?


Jawab :

Untuk mendapatkan CCNA Anda bisa mengikuti salah satu dari tiga cara ini :
Pertama, belajar mandiri. Anda mencari sumber belajar dan mempraktikannya sendiri.

Kedua, mengikuti training di Cisco Academy/Cisco Learning Partner. Cisco Academy biasanya ada dikampus-kampus/SMK dan membutuhkan waktu yang lama untuk menempuh 4 modul CCNA. Cisco Learning Partner biasanya ada di kota2 besar seperti Jakarta.

Ketiga, mengikuti training FastTrack. Dengan program FastTrack Anda mendapatkan delivery materi dengan waktu yang relatif singkat, bisa 4-6 hari.

ccna-learn

6 | Mengapa harus ikut training CCNA?


Jawab :

Tidak ada keharusan untuk mengikuti training CCNA ketika Anda ingin mengambil ujian CCNA. Cisco sendiri tidak menjadikan syarat training sebagai syarat untuk mengikuti ujian CCNA. Jika Anda sudah pede untuk ujian, bisa langsung daftar ke perwakilan Pearson Vue, tapi jika belum pede, disarankan untuk mengikuti training, karena jika Anda gagal dalam mengerjakan soal ujian CCNA maka Anda akan kehilangan 295 USD + biaya administrasi dan tidak bisa di retake lagi.

7 | Apa saja yang harus dipelajari biar bisa lulus ujian CCNA?


Jawab :

Materi ujian dapat dilihat di Exam Topics di sini. Agar Anda bisa lulus, Anda harus menguasai topik yang akan diujikan.

8 | Bagaimana kita tahu lulus ujian CCNA atau tidak?


Jawab :

Setelah Anda mendaftar ujian ke perwakilan Pearson Vue, selanjutnya Anda tinggal ujian pada hari dan jam yang telah ditentukan sendiri atau mengikuti jadwal dari perwakilan Pearson Vue.

Kemudian setelah Anda selesai ujian, begitu di submit jawaban yang telah diisi maka akan keluar hasilnya dan exam report akan dikirimkan oleh Admin ke email Anda, contoh seperti berikut ini : (Lihat pada status Grade : jika lulus isinya Pass, jika gagal isinya Failed)

ccna-exam-report

Kalau sudah lulus CCNA, Anda akan mendapatkan nomor Cisco ID (atau biasanya disebut nomor cantik Cisco) dan nomor sertifikat dapat di verifikasi di web cisco http://www.cisco.com/go/verifycertificate (contohnya seperti dibawah ini)

ccna-verified

ccna-issued

9 | Berapa passing grade untuk ujian CCNA?


Jawab :

Passing grade adalah nilai minimal untuk lulus ujian CCNA. Anda harus mendapatkan score diatas 825 dari nilai total 1000. Jika dibawah 825 Anda tidak lulus ujian CCNA.

ciscoacademy

CCNA R&S CERT

 

ccna-verified (1)

ccna-issued (1)

10 | Berapa soal yang harus saya kerjakan dan berapa lama waktunya ?

Jawab :

Berdasarkan informasi dari website Cisco, lama ujian 90 menit dan jumlah soal 50-60.
Untuk orang Indonesia lama waktu ujian 120 menit karena bukan native English.

11 |Bagaimana bentuk soal ujian CCNA?


Jawab :

Bentuk soal ujian bisa berupa :

  • Multiple-choice single answer
  • Multiple-choice multiple answer
  • Drag-and-drop
  • Fill-in-the-blank
  • Testlet
  • Simlet
  • Simulations (Lab)

12 | Jika sudah lulus CCNA, berapa lama masa aktif CCNA-nya?


Jawab :

Masa aktifnya 3 tahun, setelah itu bisa re-exam CCNA lagi atau bisa ngambil ujian diatasnya sebelum masa aktifnya habis.

13 |Apakah saya boleh menambahkan CCNA dibelakang nama saya di CV?


Jawab:

Selama sudah lulus menempuh ujian CCNA+masih aktif CCNA-nya, maka Anda boleh menambahkan CCNA dibelakang nama Anda, misalnya ‘Nama Anda, CCNA’.

 


Tabel Pilihan Macam-macam Sertifikasi Cisco

Tabel Pilihan Macam-macam sertifikasi cisco _ alvin-blctelkom

Screenshot at 2016-08-22 22-08-05

cisco 2

Kiat Sukses Menjadi Seorang Network Engineer

NETWORKING

Kiat Sukses Menjadi Seorang Network Engineer


Antara lain adalah dengan mengikuti sertifikasi seperti sertifikasi CCNA (Cisco Certified Network Associate), meningkatkan pengalaman dan kemampuan problem solving dengan mengikuti training komputer, mengikuti kursus komputer. Silakan simak ulasan, tips dan kiat sukses menjadi seorang network engineer di artikel ini agar anda dapat memaksimalkan potensi yang ada didalam diri anda.

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Intinya adalah ada keinginan untuk terus belajar dan belajar, serta mencoba untuk menerapkan apa yang didapat selama kursus, training, atau sertifikasi tersebut. Berikut ini akan sedikit dijabarkan bagaimana kiat sukses untuk para network engineer.

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Selayang pandang tentang tugas dan kiat sukses menjadi seorang network engineer

Tabel Pilihan Macam-macam sertifikasi cisco _ alvin-blctelkom

Berdasarkan Merriam-Webster English Dictionary “Network” memiliki pengertian sebagai “sebuah lingkungan yang memiliki interkoneksi atau inter-relasi berupa keterkaitan atau pengelompokkan sebuah sistem” . Secara spesifik, network yang kita bahas disini adalah sebuah sistem interkoneksi perangkat komputer beserta beserta seluruh periferalnya (modem, router, switch, terminal dan sebagainya).

Sedangkan “Engineer” memiliki makna sebagai seseorang yang terdidik atau terlatih secara spesifik untuk bidang teknis tertentu.

Jika dilihat dari perspektif tugas yang lebih spesifik, profesi network engineer dapat dibagi lagi menjadi beberapa golongan profesi, antara lain networking engineer, system engineer, network analyst, network consultant, system manager, network manager, dan network associate. Pembagian ini didasarkan pada konsep tanggung jawab dan tugas yang lebih spesifik namun secara umum tetap berhubungan dengan sistem komputerisasi yang terintegrasi melalui jaringan.

Cakupan tugas (job description) seorang network engineer


Secara umum, seorang network engineer memiliki tugas untuk mengawasi atau melakukan instalasi, melakukan konfigurasi, dan melakukan pemeliharaan (maintenance) sistem informasi dan jaringan. Tanggung jawab umum yang biasanya menjadi tugas seorang network engineer adalah sebagai berikut :

  1. Melakukan instalasi hardware, sistem atau software baru yang digunakan dalam jaringan.
  2. Melakukan instalasi, konfigurasi, dan perawatan layanan jaringan (network services) dan perangkat jaringan.
  3. Mendukung fungsi administratif pada penggunaan perangkat jaringan.
  4. Mengatur protokol untuk pencadangan (backup) atau restorasi (restore) didalam sistem.
  5. Merencanakan dan memberikan dukungan untuk implementasi infrastruktur jaringan komputer.
  6. Melakukan perbaikan (troubleshooting) atau analisis terhadap server, komputer kerja (workstations) dan semua yang berkaitan dengan hal tersebut.
    Mendokumentasikan permasalahan-permasalahan yang terjadi didalam jaringan untuk referensi dimasa yang akan datang
  7. Memonitor kinerja sistem dan dapat mengimplementasikan performance tuning.
  8. Mengatur akun pengguna (users account), izin pengguna (users permission), serta implementasi firewall, dan sistem keamanan.
  9. Memperhatikan aspek keamanan pada aplikasi dan jaringan.

Perusahaan atau korporat besar dan ternama biasanya lebih spesifik dalam memilih network engineer untuk menangani jaringan komputerisasi ditempat mereka. Perusahaan-perusahaan seperti ini mengharuskan setiap network engineer untuk memiliki kemampuan teknis dan requirement tertentu, misalnya :

  1. Memiliki sertifikasi training CCNA, MCSE, CCNP, CCIE, CNE (Cisco), MTCNA (MikroTik), atau JNCIA (Juniper) dan sejenisnya.
  2. Memiliki pendidikan setara sarjana atau D3 untuk bidang pengetahuan komputer, informasi teknologi, atau sejenisnya.
  3. Memiliki pengetahuan baik untuk sistem berbasis Windows, Cisco, Unix, Linux atau Novell
  4. Memiliki kemampuan dalam mengoperasikan dan menggunakan perangkat jaringan seperti switch, router, hub, kabel, firewall, dan lain-lainnya.

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Ada beberapa kiat sukses menjadi seorang network engineer yang dapat saya sampaikan, dan anda dapat menyimaknya dibagian ini.

1 | Pertama

Untuk menjadi seorang network engineer yang sukses, anda wajib untuk memiliki pengetahuan dasar tentang konsep dan implementasi jaringan komputer serta memiliki kemampuan analisis dan pengalaman yang memadai.

Anda dapat mengikuti training komputer atau kursus komputer yang berhubungan spesifik dengan jaringan komputer pada lembaga-lembaga tertentu yang terakreditasi untuk mengimprovisasi pengetahuan dan kemampuan analisis anda dibidang jaringan.

Sedangkan untuk mengembangkan kemampuan dan pengetahuan teknis, anda juga dapat mengikuti sertifikasi dan training Cisco, training mikrotik, atau sejenisnya di lembaga yang memang memiliki otorisasi untuk melakukan sertifikasi dan training tersebut. Salah satu lembaga training dan sertifikasi yang direkomendasikan adalah NetCampus Training Center.

NetCampus Training Center sendiri adalah penyelenggara layanan training dan sertifikasi IT, komputer dan networking terbaik di Indonesia. Selain training CCNA, Netcampus juga membuka kesempatan anda untuk mengasah kemampuan dibidang komputer secara umum dengan mengadakan training komputer dan kursus komputer.

2 | Kedua

Network engineer mengemban peranan penting yakni memastikan kelancaran operasional dan komunikasi didalam jaringan dengan tujuan menciptakan kinerja maksimum pada jaringan komputer dalam sebuah perusahaan sehingga perusahaan dapat lebih efektif dalam pencapaian target atau pencapaian Return of Investment (ROI).

Tingkat kesulitan tugas seorang network engineer sangat dipengaruhi oleh cakupan lingkungan kerja – semakin besar perusahaan tempat anda bekerja, maka semakin banyak kesulitan yang akan anda temui. Dan oleh sebab itu, kiat sukses untuk menjadi seorang network engineer selanjutnya adalah terus belajar dari pengalaman yang anda dapatkan serta dapat melakukan budgeting yang efisien (cost efficients) sehingga pengeluaran untuk IT dapat ditekan.

3 | Ketiga

Seorang network engineer yang baik dapat mengaplikasikan seluruh kemampuan (skills) yang ada pada dirinya, baik kemampuan teknis, kemampuan bernegosiasi dan berkomunikasi, melakukan managemen waktu yang baik, menerapkan profesionalisme dalam bertugas, dan lain-lain. Hal ini akan menjadi nilai plus dan merupakan salah satu kiat sukses menjadi seorang network engineer yang dapat anda lakukan.

4 | Keempat

Adalah kesabaran. Tidak jarang seorang staf IT memiliki jadwal kerja yang “berbeda” jika dibandingkan dengan staf lainnya. Network engineer kadang bisa bekerja sampai larut atau bahkan masuk di shift malam saat staff lain sudah pulang.

Tujuannya tidak lain adalah agar dapat melakukan problem solving didalam jaringan. Hal ini dilakukan agar tidak menjadi kendala dalam kegiatan operasional secara umum. Oleh karena itu kesabaran adalah kunci penting agar menjadi sukses sebagai seorang network engineer.

Kesimpulan


  • Network engineer memiliki peran penting dalam melakukan dan memberikan dukungan untuk kegiatan yang berhubungan dengan jaringan komputer di sebuah perusahaan.
  • Profesi network engineer dapat dibagi menjadi beberapa golongan sesuai dengan cakupan tugas yang dilakukan.
  • Ada beberapa kiat sukses menjadi seorang network engineer antara lain dengan mengikuti pelatihan tambahan untuk memperkaya pengetahuan seputar dunia networking.

Demikian gambaran kerja (job description) dan beberapa kiat sukses menjadi seorang network engineer yang dapat saya jabarkan disini. Semoga bermanfaat untuk anda, dan salam sukses! 🙂

 

 

Network Planning and Design

From Wikipedia, the free encyclopedia

Network planning and design is an iterative process, encompassing topological design, network-synthesis, and network-realization, and is aimed at ensuring that a new telecommunications network or service meets the needs of the subscriber and operator. The process can be tailored according to each new network or service.

Contents


1 | A Network Planning Methodology
2 | The Role of Forecasting
3 | Dimensioning
4 | Traffic Engineering
5 | Survivability
6 | Tools


1 | A Network Planning Methodology


A traditional network planning methodology in the context of business decisions involves five layers of planning, namely:

  • Need Assessment and Resource Assessment
  • Short-term Network Planning
  • IT Resource
  • Long-term and Medium-term Network Planning
  • Operations and Maintenance.

Each of these layers incorporates plans for different time horizons, i.e. the business planning layer determines the planning that the operator must perform to ensure that the network will perform as required for its intended life-span. The Operations and Maintenance layer, however, examines how the network will run on a day-to-day basis.

The network planning process begins with the acquisition of external information. This includes:

  • Forecasts of how the new network/service will operate;
  • The economic information concerning costs; and
  • The technical details of the network’s capabilities.

Planning a new network/service involves implementing the new system across the first four layers of the OSI Reference Model. Choices must be made for the protocols and transmission technologies.

Network planning process involves three main steps:

  • Topological Design: This stage involves determining where to place the components and how to connect them. The (topological) optimisation methods that can be used in this stage come from an area of mathematics called Graph Theory. These methods involve determining the costs of transmission and the cost of switching, and thereby determining the optimum connection matrix and location of switches and concentrators.
  • Network-Synthesis: This stage involves determining the size of the components used, subject to performance criteria such as the Grade of Service (GOS). The method used is known as “Nonlinear Optimisation”, and involves determining the topology, required GoS, cost of transmission, etc., and using this information to calculate a routing plan, and the size of the components.
  • Network Realization: This stage involves determining how to meet capacity requirements, and ensure reliability within the network. The method used is known as “Multicommodity Flow Optimisation”, and involves determining all information relating to demand, costs and reliability, and then using this information to calculate an actual physical circuit plan.

These steps are performed iteratively in parallel with one another.

2 | The Role of Forecasting


During the process of Network Planning and Design, estimates are made of the expected traffic intensity and traffic load that the network must support. If a network of a similar nature already exists, traffic measurements of such a network can be used to calculate the exact traffic load. If there are no similar networks, then the network planner must use telecommunications forecasting methods to estimate the expected traffic intensity.

The forecasting process involves several steps:

  • Definition of problem;
  • Data acquisition;
  • Choice of forecasting method;
  • Analysis/Forecasting;
  • Documentation and analysis of results.

3 | Dimensioning


Dimensioning a new network determines the minimum capacity requirements that will still allow the Teletraffic Grade of Service (GoS) requirements to be met. To do this, dimensioning involves planning for peak-hour traffic, i.e. that hour during the day during which traffic intensity is at its peak.

The dimensioning process involves determining the network’s topology, routing plan, traffic matrix, and GoS requirements, and using this information to determine the maximum call handling capacity of the switches, and the maximum number of channels required between the switches. This process requires a complex model that simulates the behavior of the network equipment and routing protocols.

A dimensioning rule is that the planner must ensure that the traffic load should never approach a load of 100 percent. To calculate the correct dimensioning to comply with the above rule, the planner must take on-going measurements of the network’s traffic, and continuously maintain and upgrade resources to meet the changing requirements. Another reason for overprovisioning is to make sure that traffic can be rerouted in case a failure occurs in the network.

Because of the complexity of network dimensioning, this is typically done using specialized software tools. Whereas researchers typically develop custom software to study a particular problem, network operators typically make use of commercial network planning software.

4 | Traffic Engineering


Compared to network engineering, which adds resources such as links, routers and switches into the network, traffic engineering targets changing traffic paths on the existing network to alleviate traffic congestion or accommodate more traffic demand.
This technology is critical when the cost of network expansion is prohibitively high and network load is not optimally balanced. The first part provides financial motivation for traffic engineering while the second part grants the possibility of deploying this technology.

5 | Survivability


Network survivability enables the network to maintain maximum network connectivity and quality of service under failure conditions. It has been one of the critical requirements in network planning and design. It involves design requirements on topology, protocol, bandwidth allocation, etc.. Topology requirement can be maintaining a minimum two-connected network against any failure of a single link or node. Protocol requirements include using dynamic routing protocol to reroute traffic against network dynamics during the transition of network dimensioning or equipment failures. Bandwidth allocation requirements pro-actively allocate extra bandwidth to avoid traffic loss under failure conditions. This topic has been actively studied in conferences, such as the International Workshop on Design of Reliable Communication Networks.

6 | Tools


There are a wide variety of tools available for network planning and design depending on the technologies being used. These include:

  • OPNET
  • NetSim.

OPNET

OPNET Technologies, Inc. was a software business that provided performance management for computer networks and applications.

OPNET Technologies

The company was founded in 1986 and went public in 2000. In October 2012, OPNET was acquired by Riverbed Technology, for about $1 billion US dollars.

Prior to Riverbed, OPNET was headquartered in Bethesda, Maryland and had U.S. offices in Cary, North Carolina; Nashua, New Hampshire; Dallas, Texas; and Santa Clara, California. It had international offices in Slough, United Kingdom; Paris, France; Ghent, Belgium; Frankfurt, Germany; and Singapore, with staff and consultants in multiple locations in Asia and Latin America.

Corporate History


“OPNET” was Alain Cohen’s (co-founder, CTO & President) graduate project for a networking course while he was at MIT. OPNET stood for Optimized Network Engineering Tools. Alain, along with brother Marc (co-founder, CEO & Chairman) and classmate Steven Baraniuk, decided to commercialize the software. The company’s first product was OPNET Modeler, a software tool for computer network modeling and simulation.

Since becoming a public company in August 2000, OPNET executed the following acquisitions:

  • March 2001: NetMaker Division of Make Systems
  • January 2002: WDM NetDesign B.V.B.A
  • October 2004: Altaworks Corporation
  • October 2007: substantially all of the assets of Network Physics, Inc.
  • August 2010: DSAuditor product line from Embarcadero Technologies
  • May 2012: Clarus Systems, Inc.

As an independent company, OPNET grew profitably throughout its history. SEC filings are available with further information about its IPO, annual reports, and quarterly reports.

OPNET Solutions (prior to acquisition by Riverbed)


  • Application performance management, see AppTransaction Xpert in Comparison of packet analyzers
  • Network performance management

NetSim

NetSim is a network simulation and network emulation tool used for network design & planning, defense applications and network R & D. Various technologies such as Cognitive Radio, Wireless Sensor Networks, Wireless LAN, Wi Max, MANETs, Wireless Sensor Networks, LTE, etc. are covered in NetSim.

History


NetSim is a stochastic discrete event simulator developed by Tetcos, in association with Indian Institute of Science, with the first release in June 2004.

Model Libraries in NetSim


  • Modeling and simulation are supported for the below mentioned technologies. Protocol libraries are available with C source code
  • Inter-Networks:Ethernet – Fast & Gigabit, ARP, WLAN – IEEE 802.11 a/ b / g / n / ac and e. Propagation models – Free space, Log-normal, Rayleigh Fading. Routing – RIP, OSPF. Queuing – Round Robin, FIFO, Priority TCP – Tahoe, Reno, New Reno, BIC and CUBIC, UDP
  • Common Modules with Internetworks: Applications (Traffic Generator): Voice, Video, FTP, Database, HTTP, Email, Peer-to-peer and Custom. Encryption: AES, DES. Virtual Network Stack, Simulation Kernel, Command Line Interface, Wireshark Interface, Metrics Engine with Packet Trace and Event Trace, Packet Animator
  • Legacy Networks – Aloha, Slotted Aloha, Token Ring, Token Bus, CSMA/CD
    Advanced Wireless Networks – Wi-Max, MANET covering DSR, AODV, ZRP, OLSR etc. with sinkhole / black hole attacks and intrusion detection
  • Cellular Networks – GSM and CDMA
  • Sensor Networks – Wireless Sensor Network with LEACH etc., Zigbee
  • Internet of Things (IOT) with Routing Protocol for Low Power and Loss Networks (RPL)
  • Cognitive radio Networks
  • LTE Networks, LTE Advanced Networks – SU / MU MIMO with Carrier aggregation and Relays, LTE D2D, LTE Femto Cell
  • VANETs with interfacing to SUMO through TraCI API’s
  • Military Radios – Tactical and Airborne radios in HF, VHF, UHF bands with crypto and frequency hopping,. Tactical data links, TDMA Link 16, Dynamic TDMA

In addition modules are available for sink hole attack, intrusion detection, packet encryption, packet capture using Wireshark etc.

NetSim Emulator

The Network Emulator Add on allows users to link NetSim to live applications running on real devices. This allows for real traffic to flow via the emulator and experience network effects. In this virtual network, numerous test scenarios, involving real devices and application, can be constructed and executed repetitively for normal operation as well as perturbed operation. Impairment scenarios can studied which included escalating latency, bandwidth constriction at various points, jitter tolerance, packet loss, packet reordering, route loss, failovers and single point of failure identification.

External Interfacing


NetSim can interface externally with MATLAB, Wireshark, LabVIEW and SUMO for VANETs. NetSim can also interface with live PC’s / Sensors using the emulation add-on module.

Academic Version


A deeply discounted academic version is available to universities for teaching and conducting network lab practicals. No student version is available as of date.

Applications


NetSim is widely used for

  • Network R & D including custom protocol development
  • Network lab experimentation in universities
  • Defense applications
  • Railway communication networks
  • Utilities transmission and distribution – SCADA Communication Networks.
  • Water/Waste Water, Electric Grid and Oil & Gas
  • Wireless / Satellite link emulation

Custom Code Development


NetSim comes with an in-built development environment, which serves as the interface between User’s code and NetSim’s protocol libraries and simulation kernel. Protocol libraries are available as open C code for user modification. De-bugging custom code during simulation is an advanced feature: i.e. a simulation can be started and then at user determined breakpoints in the code, users can perform single-step, step-in, step over etc. This can be carried out at various levels (depending on where the user code links) including at a per-packet interval.

Customers


Over 300 customers across 15 countries use NetSim, including premier enterprises like Philips, Hindustan Aeronautics, Indonesian Aerospace, BSNL etc. and several defense agencies like DRDO labs and space agencies like ISRO use NetSim for modeling the unique requirements of space, defense R & D and Network-centric warfare.

Hundreds of academic institutions such as Ingolstadt University – Germany, De Montfort University – UK, INTI – Malaysia, Barry University – US, Indian_Institutes_of_Technology, Dar Al Hekma – Saudi Arabia etc also use NetSim for teaching / lab experimentation and for network R & D.