IJREAS VOLUME 4, ISSUE 3 (MARCH 2014) (ISSN 2249-3905) IMPACT FACTOR – 1.776 SEGREGATION OF IP TELEPHONY PROTOCOL IN ANDROID AND WINDOWS CELL PHONES Shivani Chaudhary* Preety Joon** ___________________________________________________________________________ ABSTRACT VoIP oftenly known as IP telephony emerged as convenient protocol for transmission of voice through internet connections. VoIP technology is involved in the delivery of voice communication & multimedia sessions over ip networks. VoIP is available on many smart phones & internet devices so that users of portable devices, may place calls or send sms over 3G or Wi-Fi. The main focus of this paper is to study the VoIP technology in windows & android cell phones. Keywords— VoIP telephony, signalling control protocol, media control protocol. ___________________________________________________________________________ *Department of Computer Science, Ditm, Gannaur,Sonepat **Department of Computer Science, Ditm,Gannuar,Sonepat International Journal of Research in Engineering & Applied Sciences http://www.euroasiapub.org 161 IJREAS VOLUME 4, ISSUE 3 (MARCH 2014) (ISSN 2249-3905) IMPACT FACTOR – 1.776 I. INTRODUCTION Voice over IP (VoIP, abbreviation of voice over Internet Protocol) commonly refers to the communication protocols, technologies, methodologies, and transmission techniques involved in the delivery of voice communitions and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. Other terms commonly associated with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, IP communications, and broadband phone. Internet telephony refers to communications services —voice, fax, SMS, and/or voice- messaging applications— that are transported via the Internet, rather than the public switched telephone network (PSTN). The steps involved in originating a VoIP telephone call are signaling and media channel setup, digitization of the analog voice signal, encoding, packetization, and transmission as Internet (IP) packets over a packet-switched network. On the receiving side, similar steps (usually in the reverse order) such as reception of the IP packets, decoding of the packets and digital-to-analog conversion reproduce the original voice stream. Even though IP telephony and VoIP are used interchangeably, [1]IP telephony refers to all use of IP protocols for voice communication by digital telephony systems, while VoIP is one technology used by IP telephony to transport phone calls. Early providers of voice over IP services offered business models (and technical solutions) that mirrored the architecture of the legacy telephone network. Second generation providers, such as Skype have built closed networks for private user bases, offering the benefit of free calls and convenience, while denying their users the ability to call out to other networks. This has severely limited the ability of users to mix-and-match third-party hardware and software.[2]Third generation providers, such as Google Talk have adopted the concept of Federated VoIP – which is a complete departure from the architecture of the legacy networks. These solutions typically allow arbitrary and dynamic interconnection between any two domains on the Internet whenever a user wishes to place a call. VoIP systems employ session control protocols to control the set-up and tear-down of calls as well as audio codecs which encode speech allowing transmission over an IP network as digital audio via an audio stream. The choice of codec varies between different implementations of VoIP depending on application requirements and network bandwidth; some implementations rely on narrowband and compressed speech, while others support high fidelity stereo codecs. Some popular codecs include u-law and a-law versions of G.711, G.722 which is a high-fidelity codec marketed as HD Voice by Polycom, a popular open source voice codec known as iLBC, a codec that only uses 8 Kbit/s each way called G.729, and many others. VoIP is available on many smart phones and Internet devices so that users of portable devices that are not phones, may place calls or send SMS text messages over 3G or Wi-Fi. International Journal of Research in Engineering & Applied Sciences http://www.euroasiapub.org 162 IJREAS VOLUME 4, ISSUE 3 (MARCH 2014) (ISSN 2249-3905) IMPACT FACTOR – 1.776 Figure.1: Example of Residential network including VoIP II. STUDY The cogitation of VOIP include VoIP Engine for the Android/ARM is a software package that handles the processing needed to transform PCM samples to VoIP packets and VoIP packets to PCM samples. In other words, it provides all the voice processing necessary to VoIP-enable an Android/ARM application. The core of VoIP Engine is an Android native- layer application that includes a complete suite of Adaptive Digital’s field-proven telephony, VoIP, and voice quality enhancement algorithms that enable developers to create toll-quality next generation mobile applications for Android/ARM users. Adaptive Digital’s VoIP Engine brings the necessary VoIP functionality to the native layer. All the developer needs to do is access the VoIP engine using a simple API, and package the supplied VoIP Engine native layer application with the end user Android application. VoIP Engine is supplied with a sample Java application that interfaces to the VoIP Engine native application.[1]The sample application uses the VoIP Engine API, which in turn uses the Java Native Interface (JNI), to setup an RTP/IP to RTP/IP VoIP connection. Android developers can incorporate the Java sample code into more complete VoIP-enabled Android applications. Included Software Voice Quality: AEC, AGC; Network Optimization: Adaptive Jitter Buffer, PLC (G.711 Appendix 1);Compression: G.711 Appendix 2; Protocol: RTP;Telephony: Tone Generation; Optional Software Features:Voice Quality Enhancement; Noise Reduction; Voice codec;: G.726, G.729 AB, G.722 (wideband),AMR WB G.722.2 (Wideband), AMR NB (Narrowband),EVRC-B, MELP; Protocol stacks: SIP. The lineaments are also crucial like, by leveraging VoIP Engine, developers can focus on the functionality of the end application without dealing with the complexities of voice processing at the native layer. Also it enables VoIP application development strictly at the Java layer. The adaptive Digital’s VoIP Engine provides all the voice processing necessary to VoIP-enable an Android/ARM or vertical device mobile application. Adaptive Digital provides customers with expertise in integration and development to enable differentiation of their next gen mobile application. Adaptive Digital brings 16 years of voice/VoIP technology experience to the mobile digital device market. International Journal of Research in Engineering & Applied Sciences http://www.euroasiapub.org 163 IJREAS VOLUME 4, ISSUE 3 (MARCH 2014) (ISSN 2249-3905) IMPACT FACTOR – 1.776 Figure.2: Android VoIP Architecture With Windows Phone you can create apps that implement voice over IP (VoIP), and which gives a user the ability to engage in video or audio calls over the phone’s network connection. When the user installs your VoIP app, the app shows up in the user’s App list like any other app. However when an incoming call arrives for a VoIP application. A Windows Phone VoIP app is comprised of several components that run in one of two processes, and one component that runs outside of any process. The first process is the foreground process that displays the app UI. The second process is a background process that does most of the work of creating, connecting, and managing incoming and outgoing calls. Foreground app: The component that provides the UI for your app. It appears in the phone App list like any other Windows Phone app, and you can pin to the Start screen as an app Tile.[3]The component runs in the foreground process, also just like any other app. In addition to providing the UI, the foreground app sets up the push notification channel on which incoming calls arrive. It also launches the background process and uses the out-of- process server to pass commands to the components in the background, such as requesting that a call be ended. Out-of-process server: The server that the foreground app and the background components use to communicate between processes. International Journal of Research in Engineering & Applied Sciences http://www.euroasiapub.org 164 IJREAS VOLUME 4, ISSUE 3 (MARCH 2014) (ISSN 2249-3905) IMPACT FACTOR – 1.776 Figure.3: Windows VOIP Architecture Background agents: The four background agents that a VoIP app uses. These agents are written using managed code and are launched to indicate that a new phase of a VoIP call has begun.[2] In general, these agents have very little code, and just pass the state of the call in to one of the following components that do most of the work. That is VoIPhttpIncomingCallTask, VOIP ForegroundLifetimeAgent, VoIP CallInProgressAgent, and VoIP KeepAliveTask. Windows Phone Runtime assembly: An assembly that does most of the work of connecting and managing VoIP calls using theVOIPCallCoordinator and VOIPPhoneCall objects. Because this is a Windows Phone Runtime assembly instead of managed, it can call the native APIs to use for audio and video processing. Native core assembly: Many VoIP app developers support multiple platforms, and often have a core library written in C or C++. This library can be used in a Windows Phone VoIP app to support code reuse and speed app development. VoIP cloud service: The VoIP service that runs remotely. III. CONCLUSION This paper reveals the cogitation of VoIP implementation in Android and Windows Cell phones. The VoIP in both cell phones have different architecture which may lead to generation of new technique similar in both. The ending reveals that android phones uses simple sip protocol & the codecs used are G.711, G.722, GSM, G.729 & other capabilities include: VOIP over wifi or 3G iOS only - Push Notifications, video, number rewriting, address book matching, sms for betamax providers and pennytel. Also windows uses SIP, AIM, iChat, MSN, Yahoo kind protocols & other capabilities include: Online Phone over Edge, UMTS, 3G, Call Land and Cell phone, Voicemail, AOL, iChat, Yahoo! Messenger, Windows Live.