Showing posts with label interview questions. Show all posts
Showing posts with label interview questions. Show all posts

Sunday, 24 April 2016

Networking interview questions


1) What is a Link?
A link refers to the connectivity between two devices. It includes the type of cables and protocols used in order for one device to be able to communicate with the other.
2) What are the layers of the OSI reference model?
There are 7 OSI layers: Physical Layer, Data Link Layer, Network Layer, Transport Layer, Session Layer, Presentation Layer and Application Layer.
3) What is backbone network?
A backbone network is a centralized infrastructure that is designed to distribute different routes and data to various networks. It also handles management of bandwidth and various channels.
4) What is a LAN?
LAN is short for Local Area Network. It refers to the connection between computers and other network devices that are located within a small physical location.
5) What is a node?
A node refers to a point or joint where a connection takes place. It can be computer or device that is part of a network. Two or more nodes are needed in order to form a network connection.
6) What are routers?
Routers can connect two or more network segments. These are intelligent network devices that store information in its routing table such as paths, hops and bottlenecks. With this info, they are able to determine the best path for data transfer. Routers operate at the OSI Network Layer.
7) What is point to point link?
It refers to a direct connection between two computers on a network. A point to point connection does not need any other network devices other than connecting a cable to the NIC cards of both computers.
8) What is anonymous FTP?
Anonymous FTP is a way of granting user access to files in public servers. Users that are allowed access to data in these servers do not need to identify themselves, but instead log in as an anonymous guest.
9) What is subnet mask?
A subnet mask is combined with an IP address in order to identify two parts: the extended network address and the host address. Like an IP address, a subnet mask is made up of 32 bits.
10) What is the maximum length allowed for a UTP cable?
A single segment of UTP cable has an allowable length of 90 to 100 meters. This limitation can be overcome by using repeaters and switches.
11) What is data encapsulation?
Data encapsulation is the process of breaking down information into smaller manageable chunks before it is transmitted across the network. It is also in this process that the source and destination addresses are attached into the headers, along with parity checks.
12) Describe Network Topology
Network Topology refers to the layout of a computer network. It shows how devices and cables are physically laid out, as well as how they connect to one another.
13) What is VPN?
VPN means Virtual Private Network, a technology that allows a secure tunnel to be created across a network such as the Internet. For example, VPNs allow you to establish a secure dial-up connection to a remote server.
14) Briefly describe NAT.
NAT is Network Address Translation. This is a protocol that provides a way for multiple computers on a common network to share single connection to the Internet.
15) What is the job of the Network Layer under the OSI reference model?
The Network layer is responsible for data routing, packet switching and control of network congestion. Routers operate under this layer.

Tuesday, 19 April 2016

RF Drive Test Questions


RF drive test questions which can be probably ask by interviewer.

so before to face the interview you must well prepared.



Q.1: Please introduce the telecommunication/wireless system configuration.

GSM: MS-BTS-BSC-MSC WCDMA:UE-NODEB-RNC-CN

Q.2: Tell us 2G/3G(known) parameter which mostly concern in drive:

GSM:
RX Level (Received signal level):
-70dbm to 0dbm:Excellent; -70dbm to -80dbm:Good; -80dbm to -90dbm: Average ; -100 dbm -90dbm:worst 

RX Quality (Recieved signal quality):
0 to 4 :good;   4 to 6 normal; up 6 bad;

C/I: Carries power / Interface power

WCDMA:
RSCP: Recieved signal code power
-70dbm to -20dbm Excellent  ;-70dbm to -80dbm: Good;-80dbm to -90dbm: Average; -100 to -90:bad ,below -100 is worst.

Ec/Io: Chip energy / Interface of other cell:
0 to -6:good;-6 to -10: normal;-10 to -12:acceptance; below -12:bad.

Q.3: What is Swap and how many types of there?


Interchanging of feeder cables is nothing as swap.
there are 3 types of swap.
1- Sector Swap - when feeder A cables connected in B, and B cable in A.
2-Cyclic Swap- when feeder A cable connected in B, B cable connected in C, C cable connected in A.
3- Diversity Swap- When main feeder cable connected in diversity port and diversity cable connected in main port.

Q.4: Please analysis of causes of call drop?

Poor coverage:
Coverage hole, dead zone, isolated island, uplink/downlink unbalance Coverage over shooting Signal attenuation.
Interference:
Internal interference, external interference and the equipment interference ;Strong downlink/ uplink  interference.
Parameter setting not proper:
Radio link timeout counter, handover, power control, time slot busy.

Q.4: How many types of call drop there?

2 Types of call drop are there
1-SD drop- when user dial a number and without information its get disconnect.
2-TCH drop- when user dial and it shows with beep like going to connect, due to TCH busy and time slot not availble its get disconnected. shortly can say after allocation get disconnected.

Q.5: Please analysis of causes of handover failure?

1-missing neighbor or neighbor not defined.
2-when neighbor cell dont have free time slot.
3- swap in neighbor cell.
4- interference.


Q.6: Difference between handover and cell reselection?

When user moving in idle mode is nothing cell reselection and when user moving in dedicated mode nothing as handover.


Q.7: Introduce the software and test equipment you have used Software:

 TEMS product:TEMS9.1;8.14;8.03;
 Nemo
 Probe1.5,probe1.4;probe1.3; assistant analysis
 Mapinfo:9.0;8.5;7.0;
 actix analysis
 Test mobile:
sonyerrisson: k800i; k790i; z750i; w600; w995
Nokia: 6680; N70; N80
Motorola: V3XX

Q.8: Introduce the mapinfo and googlearth?

① Check the site location from google earth or mapinfo
② check the entironment nearby the site and make a plan for the testing from google earth and mapinfo;
 analysis the logfile from mapinfo.

Q.9: how can analysis the logfile and make report?

 actix software analysis
 Tems software analysis
 assistant software analysis
Check coverage,quality ,handover and Throughput and so on.

Q.10: In which tool frequency plan will done?

Atoll software.