Designing a Voice over IP Network in Visual Studio .NET

Creating DataMatrix in Visual Studio .NET Designing a Voice over IP Network

Designing a Voice over IP Network
Making Data Matrix In VS .NET
Using Barcode printer for .NET Control to generate, create Data Matrix 2d barcode image in .NET framework applications.
Decode Data Matrix In VS .NET
Using Barcode decoder for VS .NET Control to read, scan read, scan image in .NET applications.
Designing a Voice over IP Network
Barcode Generation In .NET Framework
Using Barcode maker for VS .NET Control to generate, create barcode image in VS .NET applications.
Barcode Scanner In .NET
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
laboratory test of each of the codec choices under ideal and degraded circumstances before making any firm decision Those tests should include tests with silence suppression turned on and turned off The packetization interval is also important A longer packetization interval means a net lower overhead for the Real-Time Transport Protocol (RTP), User Datagram Protocol (UDP), and Internet Protocol (IP) headers, which means lower bandwidth consumption overall On the other hand, a longer packetization interval means a longer delay, which impacts voice quality Typically, we will find that a packetization interval of about 20 to 40 milliseconds provides a good balance between delay and bandwidth consumption The exact packetization delay will depend on the chosen codec For example, G729 operates on 10-millisecond speech samples, so we could not choose a 25-millisecond packetization interval with G729 Similarly, G7231 operates on 30-millisecond speech samples, which means that we could not choose a 20-millisecond packetization delay with that codec For our example network design, we will assume that we use G729B (G729 with silence suppression) and with a packetization interval of 20 milliseconds Voice Activity Factor Since we have decided that we will use silence suppression, our VoIP MGs will transmit little or no IP voice traffic during periods of silence Consequently, we can reduce the amount of bandwidth that we will require on the network Therefore, we must decide how much of a typical conversation is actual voice rather than silence Clearly, if a typical voice conversation is 80 percent voice and 20 percent silence, greater bandwidth will be required compared to 60 percent voice and 40 percent silence In fact, we consider voice activity on a one-way basis only This is because transmission facilities are generally symmetrical For example, if we deploy a DS3 (approximately 45 Mbps), then we have about 45 Mbps of bandwidth in each direction If we typically have 40 percent voice activity per person in a call, then there is voice activity for about 80 percent of the time and silence for 20 percent of the time In each direction, however, we are consuming approximately 40 percent of the bandwidth that would be consumed in a call where each party is speaking 100 percent of the time In other words, we are consuming 40 percent in the direction from A to B and 40 percent in the direction from B to A, which amounts to 40 percent overall Statistics show that in a typical conversation each party speaks for approximately 30 to 40 percent of the time, with the remainder of the time
DataMatrix Creation In C#
Using Barcode printer for Visual Studio .NET Control to generate, create Data Matrix ECC200 image in Visual Studio .NET applications.
Generating ECC200 In .NET
Using Barcode generator for ASP.NET Control to generate, create Data Matrix 2d barcode image in ASP.NET applications.
Downloaded from Digital Engineering Library @ McGraw-Hill (wwwdigitalengineeringlibrarycom) Copyright 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website
Data Matrix 2d Barcode Creator In VB.NET
Using Barcode generator for Visual Studio .NET Control to generate, create Data Matrix image in VS .NET applications.
Linear Barcode Printer In .NET
Using Barcode drawer for .NET framework Control to generate, create Linear 1D Barcode image in .NET applications.
Designing a Voice over IP Network
Generating GS1 128 In .NET
Using Barcode printer for .NET Control to generate, create GS1-128 image in VS .NET applications.
Create 2D Barcode In .NET Framework
Using Barcode creator for .NET Control to generate, create Matrix Barcode image in .NET framework applications.
9
Paint EAN13 In Visual Studio .NET
Using Barcode drawer for Visual Studio .NET Control to generate, create EAN-13 Supplement 5 image in Visual Studio .NET applications.
Standard 2 Of 5 Creation In VS .NET
Using Barcode creator for .NET Control to generate, create 2/5 Industrial image in Visual Studio .NET applications.
consumed by silence For the purposes of our example network design, we will assume a voice activity factor of 40 percent
Paint Code-39 In Java
Using Barcode printer for BIRT reports Control to generate, create Code 3/9 image in BIRT reports applications.
Bar Code Reader In Visual C#
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.
Blocking Probability
EAN13 Scanner In Visual Basic .NET
Using Barcode reader for .NET framework Control to read, scan read, scan image in .NET framework applications.
GS1 DataBar Stacked Drawer In Java
Using Barcode drawer for Java Control to generate, create GS1 DataBar Expanded image in Java applications.
The Erlang is the standard measure of traffic on a circuit-switched network Since our VoIP network will have interfaces to external circuitswitched networks (such as the Public Switched Telephone Network [PSTN]), we will need to use Erlangs to dimension the interfaces to those networks One Erlang corresponds to a channel being occupied for one hour Alternatively, we can think of an Erlang as representing one hour of conversation This one hour could be a single conversation that lasts 1 hour, 2 conversations that last 30 minutes each, 5 conversations that last 12 minutes each, and so on At first glance, one would think that a single channel can carry one Erlang That is not the case Imagine 5 callers that each make a 12-minute call In order for those five calls to all be carried on the same channel in a given one-hour period, then one call would need to begin exactly when another call ends Different users will not be synchronized in such a manner Therefore, we will likely find that one of our five callers will attempt to call when a different caller is using the channel That call attempt will fail Depending on the number of available channels and the amount of offered traffic, there is a statistical probability that a channel will be available when a user wants to make a call If we want to ensure that there will always be a channel available to carry a call, we would need an infinite number of channels, which is obviously not feasible Instead, we want a high probability that a channel will be available Alternatively, we want a low probability that a call will be blocked due to a lack of available channels This probability is known as blocking probability For interfaces towards the PSTN, we must decide which blocking probability we want The lower the blocking probability, the greater the service quality and the greater the number of required channels (and hence, greater cost) Appendix A, Table of Erlang B, provides a table of Erlang values for combinations of channel counts and blocking probabilities For our network design, we will assume a blocking probability of 01 percent on interfaces between the VoIP network and external circuit-switched networks
Encoding GS1-128 In C#
Using Barcode generation for .NET Control to generate, create USS-128 image in .NET applications.
USS Code 128 Creation In None
Using Barcode printer for Online Control to generate, create ANSI/AIM Code 128 image in Online applications.
Downloaded from Digital Engineering Library @ McGraw-Hill (wwwdigitalengineeringlibrarycom) Copyright 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website
Encode Data Matrix In None
Using Barcode printer for Font Control to generate, create Data Matrix ECC200 image in Font applications.
Bar Code Drawer In .NET Framework
Using Barcode maker for Reporting Service Control to generate, create bar code image in Reporting Service applications.
Copyright © OnBarcode.com . All rights reserved.