Planning and Cabling Network

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Device Selection Factor

Deciding What Switch to use (read: to Buy :p )

Selecting a Router

We need to match the characteristics of the router to its purpose. Similar to the switch, cost and interface types and speeds must be considered as well. Additional factors for choosing a router include:

  • Expandability: bisa di tambah2in ga ?? sama kek motor…bisa di kasi aksesoris lagi ga…nambah port ?? nambah modul ???
  • Media: mo pake Ethernet ?? serial?? Coaxial ??? ato kedua2nya…??
  • Operating System Features: Depending on the version of the operating system, the router can support certain features and services such as:
    • Security
    • Quality of Service (QoS)
    • Voice over IP (VoIP)
    • Routing multiple Layer 3 protocols
    • Special services such as Network Address Translation (NAT) and Dynamic Host Configuration Protocol (DHCP)

Juniper Router J2350

For the selection of devices, the budget is an important consideration. Routers can be expensive based on interfaces and features needed. Additional modules, such as fiber-optics, can increase the costs. The media used to connect to the router should be supported without needing to purchase additional modules

LAN Cabling

When planning the installation of LAN cabling, there are four physical areas to consider:

  • Work area
  • Telecommunications room, also known as the distribution facility
  • Backbone cabling, also known as vertical cabling
  • Distribution cabling, also known as horizontal cabling
    • Total length : contoh > FastEthernet hanya bisa 100m SEBELUM sinyal elektromagnetiknya mulai melemah

Each media type has its advantages and disadvantages. Some of the factors to consider are:

  • Cable length – Does the cable need to span across a room or from building to building?
  • Cost – Does the budget allow for using a more expensive media type? (use Fiber Optic maybe ?? wkwkwk)
  • Bandwidth – Does the technology used with the media provide adequate bandwidth?
  • Ease of installation – Does the implementation team have the ability to install the cable or is a vendor required? (use Wireless ???)
  • Susceptible to EMI/RFI – Is the local environment going to interfere with the signal?

Typically, when connecting different types of devices, use a straight-through cable. And when connecting the same type of device, use a crossover cable.

Straight-Through = buat Komputer “vs” Switch, Switch “vs” Router (dipakai buat yg berbeda jenis)

Cross-Over = Switch “vs” Switch, Router “vs” Router, Komputer “vs” Router (koq Komputer dengan Router ?? Router itu punya CPU sama kek Komputer…JADIIII anggep Router itu computer juga…dan memang computer kan bisa dijadiin Router juga kan ??)

Many devices allow the UTP Ethernet port to be set to MDI or MDIX. This can be done in one of three ways, depending on the features of the device:

  1. On some devices, ports may have a mechanism that electrically swaps the transmit and receive pairs. The port can be changed from MDI to MDIX by engaging the mechanism.
  2. As part of the configuration, some devices allow for selecting whether a port functions as MDI or as MDIX.
  3. Many newer devices have an automatic crossover feature.

This feature allows the device to detect the required cable type and configures the interfaces accordingly. On some devices, this auto-detection is performed by default. Other devices require an interface configuration command for enabling MDIX auto-detection. (jadi fitur MDI/MDIX itu kek lo masukin kabel straight dari switch ke switch….otomatis switch jadiin cross over,klo ga sala Router ga ada Fitur MDI/MDIX secara default de, switch ada, jadi mesti di konfig sendiri)

*RJ-11 = kabel telepon

Winchester konektor yang diatas biasanya terdapat di ISP untuk CSU/DSU

CSU/DSU (Channel Service Unit/Data Service Unit) = Hardware device yang meng konversi frame data digital dari LAN ke WAN atau sebaliknya

DSL Router..biasanya si buat ADSL (Asymmetric Digital Subscriber Line), tapi gambar yg diatas adalah versi Cisco….MAHAL PASTINYA…mending yang diabang2 elektronik…beli modem bang !! hahaha

The following terms describe the types of devices that maintain the link between a sending and a receiving device:

  • Data Communications Equipment (DCE) – A device that supplies the clocking services to another device. Typically, this device is at the WAN access provider end of the link.
  • Data Terminal Equipment (DTE) – A device that receives clocking services from another device and adjusts accordingly. Typically, this device is at the WAN customer or user end of the link.

If a serial connection is made directly to a service provider or to a device that provides signal clocking such as a channel service unit/data service unit (CSU/DSU), the router is considered to be data terminal equipment (DTE) and will use a DTE serial cable. (pokoknya yang buat clock rate adalah DCE)

DCEs and DTEs are used in WAN connections. The communication via a WAN connection is maintained by providing a clock rate that is acceptable to both the sending and the receiving device. In most cases, the telco or ISP provides the clocking service that synchronizes the transmitted signal.

For example, if a device connected via a WAN link is sending its signal at 1.544 Mbps, each receiving device must use a clock, sending out a sample signal every 1/1,544,000th of a second. The timing in this case is extremely short. The devices must be able to synchronize to the signal that is sent and received very quickly.

By assigning a clock rate to the router, the timing is set. This allows a router to adjust the speed of its communication operations, thereby synchronizing with the devices connected to it.

*nanti ada kasus tentang interface serial…”shut”..”no shut”…”protocol down”…”administratively down”…bla bla bla…nih link buat liat kasus serial kabel

Switch (yang manageable…bisa dipasangin IP…ya itu gunanya..untuk bisa di telnet trus di manage/konfig)

There are many reasons to divide a network into subnets:

  • Manage Broadcast Traffic – Broadcasts can be controlled because one large broadcast domain is divided into a number of smaller domains. Not every host in the system receives every broadcast.
  • Different Network Requirements – If different groups of users require specific network or computing facilities, it is easier to manage these requirements if those users who share requirements are all together on one subnet.
  • Security – Different levels of network security can be implemented based on network addresses. This enables the management of access to different network and data services.

Yang terhubung ke 1 switch…BIASANYA dijadikan satu subnet

Yang point-to-point kek interface port router ke interface port router yang lain…jadiin 1 subnet (contoh /30…/30 berarti ada 2 host aja…. dan

Calculating Address

Without VLSM


How to configure Router/Switch (Under Windows XP)

we will usually use HyperTerminal because most varieties of Windows have it. This program can be found under All Programs > Accessories > Communications. Select HyperTerminal.

Open HyperTerminal, confirm the chosen serial port number, and then configure the port with these settings:

  • Bits per second: 9600 bps
  • Data bits: 8
  • Parity: None
  • Stop bits: 1
  • Flow control: None

How to configure Router/Switch (Under Windows Vista, 7, Linux)

use Putty / SecureCRT…

  • bisa telnet
  • atau Serial (liat dulu di serial / COM port berapa kepasang di komputer….cara liatnya klik kanan my computer –> properties –> device manager

Network Basic Theory 5 (Transport Layer Protocols)

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Inti dari transport Layer adalah untuk untuk mengatur pertukaran data dari setiap aplikasi ke masing2 end devices yang saling terhubung

Fungsi lain dari Transport Layer adalah :

  • Memungkinkan setiap aplikasi untuk berkomunikasi dengan jaringan melalui alat/end device yang sama
  • Jika diperlukan, menjaga data diterima dengan baik oleh aplikasi yang membutuhkan (reliable & connection oriented conversation)
  • Menerapkan error-handling mechanism
  • Encapsulasi/Decapsulasi (segment/de-segment) data…membuat data rekonstruksi/dekonstruksi
  • Mengawasi komunikasi individual antar setiap aplikasi di host sumber dan di host
  • Mengidintifikasi data aplikasi yang berbeda…which is Port Number
  • Flow Control

*bayangkan kita pake video steaming….yang kita terima adalah data e-mail, kita lagi e-mail…yang kita terima adalah data dari aplikasi lain…disini lah transport layer bekerja…ensure the right data delivers to the right application that needed





Supporting Reliable Communication

3 hal dasar dari reliabilitas transport layer :

  1. Tracking transmitted data
  2. Acknowledging received data
  3. Retransmitting an unacknowledged data

Aplikasi apa aja sih yang butuh reliabilitas dalam transfer data ??

  • Email (lo bayangin klo data email yg lo terima ngaco alias error)
  • Web Page (lo lagi baca manga online, gambarnya ga keluar ato setengah2 *angry*)
  • Database
  • Etc…

Yang ga terlalu butuh reliabilitas apa aja ??

  • VoIP
  • Video Streaming (VoIP dan Streaming…kalau data segment ada yang hilang…akibatnya Cuma delay alias buffering)
  • DNS (Domain Name System)
  • Etc…

*ya tetep aja kalau ilangnya banyak bufferingnya lama doooonk ?!?!? ya itu si DL (derita loe) *kidding*



  • User Datagram Protocol (UDP)
    • UDP is a simple, connectionless protocol, described in RFC 768. It has the advantage of providing for low *overhead data delivery. The pieces of communication in UDP are called datagrams. These datagrams are sent as “best effort” by this Transport layer protocol.
      • Applications that use UDP : VoIP, DNS, Streaming Media
  • Transfer Control Protocol (TCP)
    • TCP is a connection-oriented protocol, described in RFC 793. TCP incurs additional overhead to gain functions. Additional functions specified by TCP are the same order delivery, reliable delivery, and flow control. Each TCP segment has 20 bytes of overhead in the header encapsulating the Application layer data, whereas each UDP segment only has 8 bytes of overhead.
      • Applications that use TCP : E-mail, Web Browser, File Transfer

*overhead maksud gampangnya bisa kita liat gambar diatas, lebih banyak data yang dikirim…lebih besar juga makan bandwidth

Dilihat dari gambar diatas…gw akan jelasin beberapa (dari TCP nya aja)

Sequence Number : nomor urut paket (kan klo dipecah2 gimana cara nyambungnya klo ga ada nomor urutnya??)

Ack Number : its say “okay..your packet is delivered…thanks”

Checksum : flow control…error engga ?? data yang di terima komplit engga ?

Option : gw kurang tau ini…tapi mungkin..ya opsi2 tambahannya kali yah J

The combination of the Transport layer port number and the Network layer IP address assigned to the host uniquely identifies a particular process running on a specific host device. This combination is called a socket

For example, an HTTP web page request being sent to a web server (port 80) running on a host with a Layer 3 IPv4 address of would be destined to ß THIS CALLED SOCKET !!

“Petugas” yang mengatur Port Number adalah organisasi yang dinamakan Internet Assigned Numbers Authority (IANA).

Ada 3 tipe port number :

  1. Well Known Port (port 0 sampai 1023), yaitu port2 yang biasa dipakai dalam transfer data sehari2 seperti e-mail port, chat port, web browser port, dll
  2. Registered Port (port 1024 sampai 49151), These port numbers are assigned to user processes or applications. These processes are primarily individual applications that a user has chosen to install rather than common applications that would receive a Well Known Port. When not used for a server resource, these ports may also be used dynamically selected by a client as its source port.
  3. Dynamic and/or Private Port : (port 49152 sampai 65535), Also known as Ephemeral Ports, these are usually assigned dynamically to client applications when initiating a connection. It is not very common for a client to connect to a service using a Dynamic or Private Port (although some peer-to-peer file sharing programs do).

A current list of port numbers can be found at IANA Website


Sekarang kita coba untuk melihat port number dan tipe koneksinya (UDP atau TCP ? ) melalui fitur Netstat di command prompt

  1. Tipe koneksi : TCP
  2. Source Port Number : 3126…diliat dari tipe port diatas, berarti ini adalah registered port
  3. Address host
  4. Destionation Port Number : HTTP
  5. Connection State
  6. Dan satu lagi ßSocket


Perbedaan TCP dan UDP

Penjelasan :

  • TCP terdiri dari 32 bit (lihat paling atas…bit 0-15-31)
  • Source Port Number : port tempat data asal di kirimkan (kata Cisco biasanya port random dari angka 1023 keatas)
  • Destination Port Number : port tempat aplikasi tujuan
  • Sequence Number : nomor paket…biar pas sampai ke tempat tujuan, ngurutinnya gampang, kan multiplexing (liat lagi Network Basic Theory 2), alias di pecah2 pas mo dikirim, biar beban jaringan ga berat
  • Ack Number : specified next octet “expected” by receiver…alias klo packet pertama sudah, packet kedua yang akan di tunggu, disinilah “ack” fungsinya…”ok…paket pertama sudah diterima…paket kedua nya gw tunggu ya..”
  • H. Length : Header Length…seberapa besar length alias byte yang dipakai untuk segment header
  • Reserved : reserved for future use…I guess 😀
  • Flags : menandakan session management…penjelasan nanti dibawa
  • Window Size : seberapa banyak oktet yang akan dikirim sebelum menunggu tanda “ack”… baca lebih lanjut penjelasannya dibawah tentang window size(berikut gambar)
  • TCP Checksum : used for error-checking
  • Urgent Pointer : URG…same…don’t know very much
  • Option : jika ada data2 tambahan
  • Data : data segment nya…data aplikasi nya tentu saja

One way to improve security on a server is to restrict server access to only those ports associated with the services and applications that should be accessible to authorized requestors.


Membangun Komunikasi antar device : The Three Way Handshake

  • Establishes that the destination device is present on the network
  • Verifies that the destination device has an active service and is accepting requests on the destination port number that the initiating client intends to use for the session
  • Informs the destination device that the source client intends to establish a communication session on that port number

Dalam koneksi TCP, host yang berfungsi sebagai client meng-inisialisasi session ke server. The three steps in TCP connection establishment are:

  1. Client yang meng-inisialisasi mengirimkan sebuah segment yang berisi initial sequence value (nilai sequence awal), yang mana berfungsi untuk merequest ke server untuk memulai sesi komunikasi…“bos…hallo…bisa ngobrol sebentar ga ?!?!”
  2. Server merespon dengan mengirimkan segment yang berisi ack value yang nilainya sama dengan received sequence value ditambah 1, dan juga ditambah dengan synchronizing sequence value dari server itu sendiri. Kenapa ditambah 1 ??? karena pas dikirim balik, ga ada segment yang perlu di acknowledged. Acknowledgement sepeti ini memungkinkan client untuk mengikat respon balik yang berasal dari original segment yang dikirim ke server…“iya…kenapa..gw merespon ni…mo ngapain ente ??”
  3. Client yang meng-inisialisasi merespond dengan acknowledgement value yang setara dengan sequence value yang di terima dari server ditambah 1. Selesai deh process meng-establish connection

To understand the three-way handshake process, it is important to look at the various values that the two hosts exchange. Within the TCP segment header, there are six 1-bit fields that contain control information used to manage the TCP processes. Those fields are:

  • URG – Urgent pointer field significant
  • ACK – Acknowledgement field significant
  • PSH – Push function
  • RST – Reset the connection
  • SYN – Synchronize sequence numbers
  • FIN – No more data from sender

Field2 bit ini lah yang disebut FLAGS… the value of one of these fields is only 1 bit and, therefore, has only two values: 1 or 0. When a bit value is set to 1, it indicates what control information is contained in the segment.

Gambar diatas adalah process terminasi session.

Untuk lebih jelas tentang three way handshake….

pakailah wireshark J


The initial window size is determined during the session startup via the three-way handshake.

Taken from Tcpipguide.com, What is Window Size…In a connection between a client and a server, the client tells the server the number of bytes it is willing to receive at one time from the server; this is the client’s receive window, which becomes the server’s send window. Likewise, the server tells the client how many bytes of data it is willing to take from the client at one time; this is the server’s receive window and the client’s send window.


UDP…User Datagram Protocol

Seperti yang sudah dijelaskan yang sudah2…UDP tidak menyediakan fungsi reliability, *jadi ga penting donk pake ini??

Well, TCP memakan banyak overhead….klo orang awam bilang…terlalu banyak makan bandwidth…kita perlu yang simple2 aja…contoh nya :

  • Domain Name System (DNS)
  • Simple Network Management Protocol (SNMP)
  • Dynamic Host Configuration Protocol (DHCP)
  • Routing Information Protocol (RIP)
  • Trivial File Transfer Protocol (TFTP)
  • Online games…yes..ONLINE GAME…klo pake TCP…rasain aja sendiri LAG nya (ga pake TCP aja kadang suka lag hahaha)

Oke ?? sudah mengerti ?? untuk2 contoh2 aplikasi diatas…memakai UDP sangat efisien dan juga efektif (aplikasi2 tersebut ga butuh acknowledgement dalam transfer data…GA PENTING katanya J )

Note : Trivia…istilah segment kadang2 bisa di artikan sebagai datagram juga loh dalam UDP

*wokeh..selesai untuk Transport layer

Next…Network Layer…its gonnna be a looong day (baca: long read…hahaha)

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