The new service, called Skype for SIP (Session Initiation Protocol) allows workers to make calls with traditional telephones, instead of a headset hooked up to a computer.

Skype for SIP will cost about 2.1 cents per minute for calls to cellphones and landlines. Calls to phone systems using existing Skype software will be free. Businesses can also purchase online Skype numbers available in over 20 countries to receive calls from contacts and customers who are using landlines or mobile phones.

Stefan Öberg

"The introduction of Skype for SIP is a significant move for Skype and for any communication intensive business around the world," said Stefan Oberg, VP and General Manager of Skype for Business.

"It effectively combines the obvious cost savings and reach of Skype with its large user base, with the call handling functionality, statistics and integration capabilities of traditional office PBX systems, providing great economical savings and increased productivity for the modern business."

Applicants for Skype for SIP will need to be businesses and have an installed SIP based IP-PBX system along with being able to configure their own SIP-enabled PBX. The initial beta is available to a limited number of participants. The product will fully launch later this year.
 

It is a 3GPP (Third Generation Partnership Project) signaling protocol. It is one of the major signaling protocols used in Voice over IP (VoIP).

SIP was developed by IETF MMUSIC Working Group in an initiative to create a more robust standard compared to the H.323, which is a current widely used standard for voice sessions. The need was to cater to the increasing demand put by services such as video conferencing, unified messaging, and voice chatting, which are now being implemented through Internet.

SIP is based on Hypertext Transfer Protocol (HTTP). It basically deals with embedding call setup and signaling features in networking elements such as user agents and proxy servers. The signaling and call setup can be used by IP-based communication system to support the call processing functions and features present in the Public Switched Telephone Network (PSTN). SIP enables a VoIP application to have the same kind of high quality and reliability that traditional telephone systems can deliver. SIP adds quality and reliability to VoIP, which until recently has been associated with the term “low cost alternative”.

SIP handles the signaling part of a communication session. It serves as a carrier for the Session Description Protocol (SDP). SDP handles the media portion of the session. The transmission of voice and video content are done by the Real-time Transport Protocol (RTP). A SIP session thus involves packet streams of RTP. SIP is a part of the protocols involved in a multimedia session.

The major advantage of SIP is in its support for both IP and conventional telephone communication. Communication service providers can leverage on this protocol to interconnect conventional telephone and IP communication services. This especially sounds good for the vendors of VoIP telephony, wherein both the domains are involved. Owing to SIP’s roots in HTTP, voice based application can also be seamlessly integrated with web services.

SIP is scalable, easy to implement, and requires less setup time than its predecessor protocols. Being text based, it is easy to program. It is a peer-to-peer protocol, requiring no implementation in the network level. The logic is implemented at the communication endpoints, which may be in hardware or software level. Real time sessions are established when and where required. Since SIP can be used to modify any session in progress, a normal telephone call session can be converted into a multi-party videoconference. Users can join in the session no matter what kind of terminal he is using or where he is located. The other person may be logged on to Internet through a PC, or may be traveling with a cell phone.

SIP holds lot of promise in today and tomorrow’s communication world. It has been established as a standard for call control and signaling on 3G cell phone networks by the Third Generation Partnership Project (3GPP). This means that all multimedia and IP voice call signaling will be done through SIP. New services involving fixed network IP services can thus introduced with ease.

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This article has been published by AccessDirect, a leading service provider of PBX phone systems (hosted/virtual). We also provide voicemail, fax mail, follow me call forwarding, local phone numbers, and toll free numbers. Visit us at www.messagingservice.com.

John K represents AccessDirect, a leading provider of Hosted PBX, voice mail, fax mail, local phone numbers, and toll free numbers.

The two companies disclosed at Orlando’s VoiceCon 2006 they would integrate Microsoft’s Office Communicator 2005 and the open SIP-based Microsoft Office Live Communications Server 2005 with the new SIP-based Cisco Unified Communications system.

Microsoft detailed more of the capabilities of the combined solution in a statement. Users will be able to click to call and transfer calls from within Office Communicator. Calls launched from Office Communicator can then be conducted from the PC or from another phone.

Also, users can switch from instant messaging to voice calling transparently between sessions. And Office Communicator users will be able to see the status of a Cisco Unified IP Phone presence, or availability, and determine if that user is present to take a call.

At the core of the agreement, Microsoft will work with Cisco to deliver a solution that is standards-based and interoperable. That’s a big change in the way Microsoft has previously treated some standards-based technology.

Microsoft famously angered MIT and numerous users with its implementation of Kerberos in Windows 2000 Server. A Network World report from 2000 noted how companies that wanted to access print and file services on a 2000 Server from Windows 2000 desktops had to buy a Kerberos Server license to do so, even if another Kerberos server on the network could authenticate those connections.

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David Utter is a staff writer for WebProNews covering technology and business.

Instant messaging has become a preferred method of communication and collaboration, IDC reports. Enterprise messaging systems carry nearly a billion instant messages a day, with many more consumer systems brought into the workplace carrying billions of messages back and forth.

IDC cites “compliance-driven sectors” like financial and government markets as becoming big adopters of IM. “IDC expects instant messaging – once the plaything of teenagers – to continue to grow into its role as a substantial business collaboration application,” Robert P. Mahowald, program director for IDC’s Collaborative Computing research, wrote in a statement.

The study noted a few players in the IM arena as having significant impact. AOL has been pushing its business services that allow expanded functionality over IM. Jabber, used by Google for Google Talk and by many other providers, supports XMPP (Extensible Messaging and Presence Protocol) and SIP (Session Initiation Protocol). IDC claims that support has led to Wall Street embracing instant messaging.

Financial growth among messaging providers looks promising for the future. IDC said the market for instant messaging servers and related products for 2005 will be around $315 million. By 2009, that figure could grow to $736 million.

David Utter is a staff writer for WebProNews covering technology and business. Email him here.

The bad news is that if you feel writing programs in the field of networking, say for something like a live world-wide chat, is a nightmare, then you are probably feeling right. The good news, however, is that before a couple of shakes of Bruno’s tail, you will be writing your first Networking program! The program that we’ll build on right now, is to yank in a document lurking somewhere on the web (doesn’t everything just lurk somewhere out there?) into our computer. And if its kinda hard-hitting, try not to weasel out midway; it will all begin to make sense soon.

Albeit an elaborate explanation is absconding now, we expect you to try this out. Meanwhile, we will do some more slogging

Before we swoop down on the actual clutter of Resource Locators, servers, streams etc., let us remind ourselves of a basic list and a button.

Program 1

import java.awt.*;
import java.applet.*;
public class zzz extends Applet
{ public void init()
 { setLayout(new BorderLayout());
  List l;
  l = new List(3000, false);
  add("Center", l);
  add("North", new Button("Start"));
 }
}

Now, let us write the novice program.

Program 2

import java.awt.*;
import java.applet.*;
public class zzz extends Applet
{ URL u;
 public void init()
 { setLayout(new BorderLayout());
  List l;
  l = new List(3000, false);
  add("Center", l);
  add("North",new Button("Start"));
 }
 public boolean action ( Event e, Object o)
 { if ( "Start".equals(o) )
  { try
   { u=new URL("http://www.neca.com/~vmis/java.html");
    showStatus(" URL is initialised ");
   }
   catch(MalformedURLException x)
   { showStatus("error in URL");
   }
  }
  return true;
 }
}

Not as bed-wettingly scary as you thought it would be, was it? Only the vocabulary of the programming luminaries seems to be bloated with jargon. If you’ve been using the web, the kinda highfalutin word URL (Uniform Resource Locator) is perhaps at least halfway memorable by now (we wonder why it is called a URL, but we understand one can live out a full and relatively cheerful life without ever needing to know) Anyway, you will get these errors as of now…

class URL not found in type declaration
class URL not found in new
class MalformedURLException not found in type declaration
class MalformedURLException not found in catch

Therefore, we use the inevitable import , which, incidentally, is mandatory if you want to get past the compilation stage!

import java.net.*;

With that wisdom up our sleeve, let us give it another try. We first have to define a URL connection . Right after the line that says URL u , let us add this line

URLConnection c;

And later, in the action() , we write the following…

try
{ c = u.openConnection();
 showStatus("Open Connection successful");
}
catch(IOException x)
{ showStatus ("Connection failed");
}

But again, there are three errors lobbed at us which very rhetorically go as…

Exception :java.io.IOException must be caught , or it must be declared in the throws clause of this method
Class IOException not found in type declaration
Class IOException not found in catch

And that brings us to yet another import statement. This one is for the IO (and for those who came in late or didn’t come at all, that stands for “Input Output”).

import java.io.*;

As yet, whatever we are doing with our code is far from spectacular. While we are taking care of the URL and the URL connection, we conveniently forget about fetching in the file. Towards that end, we have a class called InputStream . Hence, we include the following line…

InputStream n;

Besides, our action() will now look like this…

 public boolean action ( Event e, Object o)
 { if ( "Start".equals(o) )
  { try
   { u=new URL("http://www.neca.com/~vmis/java.html");
    showStatus(" URL is initialised ");
   }
   catch(Exception x)
   { showStatus("URL not initialised");
    return true;
   }
   try
   { c = u.openConnection();
    showStatus("Open Connection successful");
   }
   catch(Exception x)
   { showStatus("Error in Open Connection");
    return true;
   }
   try
   { n = c.getInputStream();
    showStatus("getInputStream successful");
   }
   catch(Exception x)
   { showStatus("error in getInputStream");
    return true;
   }
  }
  return false;
 }

Next we have the DataInputStream class which will likewise be inserted in the following way…

DataInputStream d;

The action() will now become…

 public boolean action ( Event e, Object o)
 { if ( "Start".equals(o) )
  { try
   { u=new URL("http://www.neca.com/~vmis/java.html");
    showStatus(" URL is initialised ");
    c = u.openConnection();
    showStatus("Open Connection successful");
    n = c.getInputStream();
    showStatus("Input Stream successful");
    d=new DataInputStream(n);
    showStatus(" Data Input Stream successful");
   }
   catch(Exception x)
   { showStatus("error in URL/Connection");
   }
   return true;
  }
  return false;
 }

Note that this time we have a single catch for all the exceptions instead of having a barrage of them (though having them seperately shown is good if you want to see the exceptions explicitly). Let us also have a String and place it in the action() .

Next we have the DataInputStream class which will likewise be inserted in the following way…

DataInputStream d;

The action() will now become...
 public boolean action ( Event e, Object o)
 { if ( "Start".equals(o) )
  { try
   { u=new URL("http://www.neca.com/~vmis/java.html");
    showStatus(" URL is initialised ");
    c = u.openConnection();
    showStatus("Open Connection successful");
    n = c.getInputStream();
    showStatus("Input Stream successful");
    d=new DataInputStream(n);
    showStatus(" Data Input Stream successful");
   }
   catch(Exception x)
   { showStatus("error in URL/Connection");
   }
   return true;
  }
  return false;
 }

Note that this time we have a single catch for all the exceptions instead of having a barrage of them (though having them seperately shown is good if you want to see the exceptions explicitly). Let us also have a String and place it in the action() .

String s;

action()
try
{ s=d.readLine();
 showStatus ("String "+s);
}
catch(Exception x)
{ showStatus("String not read");
 return true;
}

Let us add this to the list.
try
{ l.addItem(s);
 d.close ();
 n.close();
}
catch(Exception x)
{ showStatus("Add Item not successful");
 return true;
}

It must be at least halfway clear that the string is being used to display inside the listwhatever has come in as a file. But the problem here is that the file is not being properly read. We’ll have a loop for the reading, so that the complete document has been read.

public class zzz extends Applet
{ URL u;
 URLConnection c;
 InputStream n;
 DataInputStream d;
 String s;
 List l;
 public void init()
 { setLayout(new BorderLayout());
  l = new List(3000,false);
  add("Center",l);
  add("North",new Button("Start"));
 }
 public boolean action ( Event e, Object o)
 { if ( "Start".equals(o) )
  { try
   { u=new URL("http://www.neca.com/~vmis/java.html");
    showStatus(" URL is initialised ");
    c = u.openConnection();
    showStatus("Open Connection successful");
   }
   catch(Exception x)
   { showStatus("error in URL/Connection");
   }
   try
   { n = c.getInputStream();
    showStatus("Input Stream Open successful");
   }
   catch(Exception x)
   { showStatus("error in get Input Stream");
    return true;
   }
   try
   { d=new DataInputStream(n);
    showStatus(" Data Input Stream Open successful");
   }
   catch(Exception x)
   { showStatus ("error in Data Input Stream");
    return true;
   }
   try
   { while ((s=d.readLine()) != null )
     l.addItem(s);
    n.close();
   }
   catch(Exception x)
   { showStatus("Add Item not successful");
    return true;
   }
  }
  return false;
 }
}

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Visit Vijay Mukhi’s Computer Institute online at http://www.vijaymukhi.com.

SIP, a signaling protocol that sets up and tears down sessions in an IP network, is best known as a standard for VoIP phones that locates and connects end users to multiparty voice- and videoconferences. If you don’t think SIP is for real yet, think again.

Click below to read this article at the NWC.com website:

http://www.nwc.com

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