IPhone 5S

This is really a cool phone with great quality and lots of extra features.  Well it is Iphone so who wouldn't want it, really great looks and design check out all the specifications.

GENERAL              

4G Network               LTE- all models

SIM                           Nano-SIM

2G Network             A1453, 800 ,1700 ,1900 , 2100 - A1533 (CDMA  

                                  GSM 850 , 900 ,1800, 1900

Announced             2013, September

3G Network              A1453,  CDMA 2000 1xEV-DO - A1533 (CDMA),    850 , 900,  1700 , 1900 , 2100 - A1533                                                                  (GSM), HSDPA 850 ,900 , 1900 , 2100 - A1457,  A1530,  HSDPA A1453,

Status                        September 2013 ( released)

Dimensions              (4.87 x 2.31 x 0.30 in) 123.8 x 58.6 x 7.6 mm 

Size                             4.0 inches , 640 x 1136 pixels, 

Protection                  oleophobic coating, Corning Gorilla Glass, 

Alert types                 proprietary ringtones,Vibration,

3.5mm jack                  Yes

DISPLAY Type          capacitive touchscreen, LED-backlit IPS LCD,  16M colors
Multitouch                 Yes
Loudspeaker              Yes
Weight                      112 g (3.95 oz)  (Touch ID

MEMORY       
       

Internal                   1 GB RAM DDR3,16/32/64 GB storage, 
Card slot                No

DATA  
   

GPRS                       Yes

Speed                   21 Mbps; HSUPA,   LTE,   DC-HSDPA, 42 Mbps;100 Mbps;  up to 3.1 Mbps,  HSDPA,  5.76 Mbps,  EV-                                         DO Rev. A,

Bluetooth              Yes, v4.0 with A2DP
EDGE                       Yes

WLAN                   dual-band,  Wi-Fi 802.11 a/b/g/n, , Wi-Fi hotspot
USB                         Yes, v2.0

CAMERA               

Features              HDR photo,  touch focus, 1/3'' sensor size, 1.5 µm pixel size, simultaneous HD video and image recording,                                 face detection, HDR panorama,  geo - tagging,

Secondary             Yes, 1.2 MP, face detection,720p@30fps,  FaceTime over Wi-Fi or Cellular, 

Primary                 autofocus, 8 MP, 3264 x 2448 pixels, check quality, dual-LED (True Tone) flash, 
Video                      check quality,Yes, 720p@120fps, video stabilization, 1080p@30fps

FEATURES    

GPU                        (quad-core graphics)   PowerVR G6430         

OS                           iOS 7, upgradable to iOS 7.0.4

Chipset                   Apple A7

CPU                         (ARM v8-based) Dual-core 1.3 GHz Cyclone

Messaging               Push Email, SMS (threaded view), iMessage, MMS, Email,

Sensors                   gyro, proximity, compass, Accelerometer,

Radio                      No

GPS                          support A-GPS  and GLONASS, Yes

Java                         No
Browser                    HTML (Safari)

Colors                    Gold,  White/Silver,  Space Gray

Features:

- AirDrop file sharing

 - Active noise cancellation with dedicated mic

- Siri natural language commands and dictation

- iCloud Keychain

- Twitter and Facebook integration
- Document viewer/editor ((Word, Excel, PowerPoint)

- TV-out

- iCloud cloud service
- Organizer

- iBooks PDF reader

- Audio/video player/editor
- Maps

- Predictive text input

- Image viewer/editor

- Voice memo/dial/command

-Stand-by                    Up to 250 h (2G) / Up to 250 h (3G)

-Music play                  Up to 40 h

-Talk time                     Up to 10 h (2G) / Up to 10 h (3G)

MISC      

SAR US                      1.12 W/kg (head)     1.18 W/kg (body)   

SAR EU                      1.00 W/kg (head)     0.80 W/kg (body)   

Price group               About 700 EUR
BATTERY                 Non-removable Li-Po 1560 mAh battery (5.92 Wh)    

TESTS     

Loudspeaker              Ring 69dB/  Noise 66dB /  Voice 68dB / 

Camera                        Video/ Photo  

Audio quality            Crosstalk -90.3dB/Noise -93.6dB 
Display                        3.565:1 (sunlight)/Contrast ratio: 1219:1 (nominal)

Battery life                   Endurance rating 54h

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Transparent Caching

the browsers should be configured explicitly to use a proxy server. this is not a headache anymore instructing each and every client to make proxy settings. Transparent caching is very handy in such cases. transparent caches are simple and they can be easily used in a network and do not require explicit coordination with other caches. Transparent caching in context of HTTP proxy caches means the transparent hijacking of the port 80, which is the default HTTP port. the cache hijacks the port 80 traffic whenever the client tries to request to the remote servers. the client does not have to configure his/her browser. instead squid transparently picks up requests and responses to the client. squid cache/proxy server acts as transparently caching servers and fulfils the clients requests of web objects, if available locally hence making efficient web browsing.

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Web Caching

web caching refers to storing locally the once referenced web objects, should any future request come for that object, it is checked for in local store and if present there it is retrieved directly from the local store instead from the original server. It saves time, bandwidth and of course money. Web caching can be done at end users desktop or on dedicated cache server. Most of the present day browsers have support for caching to some extent though they are not of high performance and limited to a computer only. the most effective way to implement cache is by service provider. they can deploy a dedicated server and high performance web caching software. Wherever caching is done the goal is the same. It is better if ISPs cache web objects so that frequently referenced sites could be serve locally instead of downloading every time from the original servers. This increases throughput dramatically. the above discussions suggests that given sufficient storage, whole internet could be cached. However this is not true, Information is dynamic in nature and so is the web. If we cache everything we end up serving stale objects to the clients. this is worse than having slow access. there are methods to ensure the freshness of an object stored in a cache.

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What is FTP ?

The FTP(File Transfer Protocol) utility program is commanly used for copying files to and from other computers. FTP is a general protocol that works on unix system as well as a variety of other (non unix) systems. FTP is basically used to promote sharing of files (computer programs and/or data), to encourage indirect or implicit(via programs) use of remote computers, to shield a user from variations in file storage systems among hosts, and to transfer data reliably and efficiently. FTP though usable direclty by a user at a terminal, is designed mainly for use by programs. FTP is in common use for downloading data and programs and for uploading files such as web sites to or from the servers of the same or different architecture.(such as windows PC,MAC ,etc).

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OSPF (Routing Protocol)

For big networks in the internet what we need is a network path which is shorter and best. OSPF is a routing protocol which enables data packets to choose the best path. It is widely popular IGP (Interior Gateway Protocol) which is implemented by most of the major network providers. OSPF stands for open shortest path first, this protocol determines the best path for routing the data traffic. OSPF does routing based on cost calculation, the path with lowest cost always gets the priority. Consider the example below in this network the lowest cost is 10 hence the packet chooses the path with lowest cost to reach the destination.

In the OSPF, whole network (single autonomous system) is divided into smaller areas so that network is optimized. OSPF uses hello packets at first to calculate the neighbors and then the routing table is updated. For smaller network (typically up to 10 routers) single area is sufficient, but for large networks single area is not sufficient. For larger networks OSPF requires multiple areas so that routing information is limited and the routers processing capacity and memory is optimized.

OSPF uses LSA (Link state Advertisement) packets to update the routing table. There are different types of LSA packets and based on these types network is designed. Different types of area for example core area and other area requires different types of routing information. Hence to distinguish these types of network routing information is either limited or maximized.

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What Is IP Address

What IS IP Address?
An IP(Internet Protocol) address is an address that is assigned to any computer or media which is connetcted to a computer network. The main concept of an IP address is to name a computer in a network so that it can be easily identified. There are two types of IP addressing that exist in the current world scenario- they are IPV4(Internet Protocol Version 4) and higher version is IPV6(Internet Protocol Version 6). IPV4 is 32 bit addressing mode from which we can address upto 2^32 computers. initially designers thought it would be enough for the world but as the technology is growing so much rapidly and most of the electronic media are IP based hence the need of IP address is growing rapidly hence the 32 bit IP addressing is not enough so now designers have chosen a new addressing scheme which consists of 128 bit addressing mode so we can address upto 2^128 computers. With this new scheme of IP address there wont be scarcity of ip address for long years to come.

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