IP address basic concept in networking

Internet Protocol (IP) address:

An identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol route messages based on the IP address of the destination. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods(192.168.1.1). Each decimal number represents eight bits of binary data, and therefore can have a decimal value between 0 and 255.

Subnet Mask:

A subnet mask is used to divide an IP address  into two parts.One part is identifes the the host (computer) , the other part identifies the network which belongs.

The first part of an IP address is used as a network address, the last part as host address.

If you take an example 192.168.1.132 and divide it into these two parts you gets the following

192.168.1.0   Network Address

 0.0.0.132      Host Address

For this example  using 255.255.255.0 subnet mask

When a packet arrives on the 192.168.1.0 subnet and it has a designation address of 192.168.1.132 , computer will receive it from the network and process it.

This means that you can use the address 192.168.1.1 to 192.168.1.254 for your computers  to connect in the network.

The number after the slash represents the number of consecutive 1's in the subnet mask.

For example 192.168.1.0/24 is equal to the network   192.168.1.0 with  255.255.255.0   sub net mask.

Network address:  192.168.1.0/24      

First computer IP address: 192.168.1.3                                                           Second computer IP address: 192.168.1.4

Third computer IP address: 192.168.1.5                          

Subnet mask: 255.255.255.0

Gate way : 192.168.1.2 (Router IP address) 

If you convert 255.255.255.0 to binary , you end up with 24 consecutive 1 's

11111111.11111111.11111111.00000000

IP                                         subnet mask

192.168.1.0/24              255.255.255.0                  

   

192.168.1.0 to 192.168.1.255     Total - 256 host address  

Adress:	192.168.1.0	11000000.10101000.00000001.00000000
Netmask:	255.255.255.0	11111111.11111111.11111111.00000000
Wildcard:	0.0.0.255	00000000.00000000.00000000.11111111
Network Address:	192.168.1.0 / 24	11000000.10101000.00000001.00000000
Broadcast Address:	192.168.1.255	11000000.10101000.00000001.11111111
First host:	192.168.1.1	11000000.10101000.00000001.00000001
Last host:	.192.168.1.254	11000000.10101000.00000001.11111110

ROUTER IP CONFIGURATION :

DHCP

Short for Dynamic Host Configuration Protocol, a protocol for assigning dynamic IP addresses to devices on a network.

IP address conflict:

If you defined a static IP address for a network device, duplicate IP address conflicts may occur on a DHCP network

This article is useful those who works in broadband maintenance,networking etc

EL/Super conductivity/SET-2/Paper-01

Q1. Superconductivity is observed for
(a) infrared frequencies
(b) dc and low frequency
(c) AC and high frequency
(d)frequency having no effect

Ans:b
Q2. superconductivity can be destroyed by

(a) adding impurities
(b) reducing temperatures
(c) application of magnetic field
(d) any of the above

Ans:c
Q3. Superconducting metal in superconductivity state has relative permeability of

(a) zero           (b) one              (c) negative              (d) more than one

Ans: a
Q4. The super conductivity is due to

(a) the crystal  structure having no atomic vibration at 0^o K
(b)all electronics interact in the super conducing state
(c)the electronics jump into nucleus at 0^o K
(d) none of those

Ans:a

Q5. The structure sensitive property of a super conductor is
(a) Critical magnetic field
(b) transition temperature
(c) Critical current density
(d) none of the above
Ans:c

Broadband Equipment MCQs Set-2

1. What for Set Top Box is used .

 (a) VOIP       (b) IPTV       (c) VPN       (d) ISDN

2. BNG in Multiplay Network is connected to

   (a) Core Router  (b) PE router  (c) DSLAM  (d) BRAS

3. Triple play Service through Broad band means

   (a)Data, Games and Audio simultaneously
   (b)Data,voice and  Games simultaneously
    (c)Data, voice and video simultaneously
   (d)Voice,Video and Audio simultaneously

4. BNG behaves as _____________________ router in BSNL multiplay

   (a) Core Router  (b) Provider Edge Router (c)Customer Edge Router  (d)Gate way router

5. Voice in Broad band Multiplay is

   (a) Voice over PSTN
   (b )Voice over IP
   (c) Voice over PLMN
   (d) Voice over ISDN

6. Set Top Box interfaces with Television using
   (a) Ethernet Port  (b) Serial Port  (c) 3- RCA cable (d) RS 232 port

_________________________________SOLUTION________________________________
1.b

2.a

PE router
BNG - Broadband Network Gateway
RPR - Tier-I Switch and Tier-2   switches in the ring Provides connectivity to BNG & Vice versa
OCLAN - Tier-2 Swich
DSLAM
ADSL CPE 

3.c

4.c  BNG behaves as Customer Edge Router where as BRAS was a PE router.

5. b BB Multiplay - The triple play service means providing the following service to the customer:

• Data (Ineternet)
• Voice (VoIP and not the PSTN)
• Video (IPTV )

6. c  On one side of  Set Top Box interfaces with the television using the 3-RCA or the S-Video ports, and on the other side it is connected to broadband ADSL modem via the Ethernet port.

Basic Electrical/Electrical circuits/Level-0/Paper-04

Q1. Which of  the following is non-linear  circuit parameter ?

(a)Inductance
(b)Condenser
(c)wire wound resister
(d)Transistor

Q2. A capacitor is generally a

(a) bilateral and active component
(b) active, passive linear and nonlinear component
(c) linear and bilateral component
(d) non-linear and active component

Q3. The circuit whose properties are same in either directions is known as

(a) unilateral circuit
(b) bilateral circuit
(c) irreversible circuit
(d) reversible circuit


Q4. The circuit has resistor, capacitor and semiconductor diode the circuit will be

(a)non linear circuit
(b) linear circuit
(c) bilateral circuit
(d) none of the above

Q5. A network which contains one or more than one source of emf is known as

(a)linear network
(b) non linear network
(c) passive network
(d)active network

______________________________SOLUTIONS________________________________________

A circuit is a closed conducting path through which an electric current either flows or is intended flow.

• Linear circuit is one whose parameters are constant  i.e. they do not change with  voltage or current.

• Non-linear circuit whose parameters change with voltage or current

Q1.a

The various elements of  an electric circuit are called its parameters like resistance,inductance and capacitance . These parameters may be lumped or distributed. 

Q2.c

• Example of passive components : resistor,capacitor,inductor etc
• Example of active components : Diode,Trasistor ,voltage source,current source etc

Q3.b

Unilateral circuit whose properties or characteristics change with the direction of its operation.A diode rectifier is a unilateral circuit , because it cannot perform rectification in both directions.

Q4.a

Q5.d

Passive Network is one in which contains no source of emf in it.

Small Form-factor Pluggable (SFP) Optical Transceivers

A SFP is a hot-swappable input/output device that plugs into the SFP ports, linking the switch with the fiber-optic network.The following SFP media types are supported:

• CWDM (CWDM-SFP-xxxx=)
• Cisco 1000BASE-T SFP (GLC-T=)
• Short wavelength 1000BASE-SX (GLC-SX-MM=)
• Long wavelength/long haul 1000BASE-LX/LH (GLC-LH-SM=)
• Extended distance 1000BASE-ZX (GLC-ZX-SM=)

A small form-factor pluggable (SFP) Gigabit LH40 transceiver that provides a full-duplex Gigabit solution up to 40 km on a single mode fiber.

• 100BASE   -   FE Fast Ethernet
• 1000BASE -   GE Gigabit Ethernet

• Long Haul ( LH ) denotes longer distances 
• Long Wavelength ( LX ) denotes less energy which is  shorter distance

Generally a SFP module is either made for single mode (More distance) / multi-mode (short distance).If used with SM fiber it can go upto 10Km

Inserting and Removing Blade-Clasp SFP module

The blade-clasp SFP module has a blade clasp that you use to secure the SFP module in a switching module port.

Waning :

Invisible laser radiation may be emitted from disconnected fiber or connectors. Do not stare in to beams or view directly with optical instruments.

Inserting a Blade-Clasp Module:

To insert a blade-clasp SFP module into a swiching module port, follow these steps:

 step 1: Close the blade-clasp before inserting the SFP module.

 step 2 : Line up the SFP module with the port, and slide into the port.

Caution:

Protect your SFP modules by inserting clean dust plugs into the SFPs after the cables are extracted from them. Be sure to clean the optic surfaces of the fiber cables before you plug them back into the optical bores of another SFP module. Avoid getting dust and other contaminants into the optical bores of your SFP modules: The optics do not work correctly when obstructed with dust.