Handoff of Softphone in IP Telephony Communication
From Dr. Mashiur Rahman :: ICT expert :: VoIP & Nanotechnology
Contents |
Abstract
Our major aim is to develop a mechanism that can efficiently transfer any kind of communication between softwares without any interruption of call. Using IP Telephony users can have flexibility such as ongoing calls can be transferred from any platform to other platform without interruption. As an example a user is calling from a computer using any software and another user is also using another computer. If for any reason (like moving to another place) the second user wants to transfer the voice communication to his mobile, in this situation IP Telephony will enable users to do that.
Our goal is to develop a mechanism which can enable a user to facilitate the handoff between software without any further interruption.
Goal of this project
- To understand how the SIP protocol works.
- How a call is established, maintained and terminated in IP telephony.
- Develop a handoff mechanism for IP telephony.
- Make IP telephony more flexible
Logbook
- 2 November 2009 : Discussion with Dr. Mashiur Rahman
- 9 November 2009: Group meeting with Dr. Mashiur Rahman
- 16 November 2009: Group meeting with Dr. Mashiur Rahman
- 17 November 2009: Demonstrated the handoff process in IP telephony lab.
Current Status Update
At Home: Alimur
- 17 November 2009: Studying related journals and RFC's.
- 5 December 2009: Learning more about RFC 3515 SIP Refer method and RFC 5589 SIP Call Control.
Prototypical REFER callflow
Agent A Agent B
| |
| F1 REFER |
| -----------------------> |
| F2 202 Accepted |
| <----------------------- |
| F3 NOTIFY |
| <----------------------- |
| F4 200 OK |
| -----------------------> |
| |
| |
| | ------->
| | (whatever)
| | <------
| |
| F5 NOTIFY |
| <----------------------- |
| F6 200 OK |
| -----------------------> |
| |
Here are examples of what the four messages between Agent A and Agent B might look like if the reference to (whatever) that Agent B makes is successful. The details of this flow indicate this particular REFER occurs outside a session (there is no To tag in the REFER request).
(SIP) Call Control
- 9th December 2009:Learing the basic of how the Call Park feature works.
Call park is a feature of some telephone systems that allows a person to put a call on hold at one telephone set and continue the conversation from any other telephone set.
At Home: Arefin
- 17 November 2009: Studying related journals and RFC's.
- 3 December 2009: Installed Fedora 11 and Asterisk.
- 17 December 2009: Implemented the project.
- 19 December 2009: Started writing the report
Screenshot: 
To Do list
- Learn how to install and use Linux on a computer
- Learn how to install and use Asterisk.
- How the problem we addressed can be solved.
- Finding more ways for doing handoff efficiently and with less interruption time.
- Our next target is the implimentation of studied factors regarding handoff.
- We will do this using Linux and Asterisk.(For transferring calls)
Presentations
Every week we need to give presentations in our group meeting.
Arefin I have already reviewed two Papers related to our project.They are listed below.
1. The mobile IP handoff between Hybrid networks.YE Min Hua, LIU Yiu, ZHANG Hui Min.IEEE Paper File:IP handoff in hybrid networks.pdf
2. Supporting Multimedia Session Mobility using SIP. Iuliana Popescu,University of NewBrunswick File:Supporting Multimedia Session Mobility using SIP.pdf
Alimur
I have also reviewed two Papers related to our project.They are listed below.
1."A comparison of mobile IP handoff mechanisms" by L.Niesink , University of Twente Enschede , January 2007. IEEE paper
2. "Minimization of Handoff interruption time optimizing IP Address Assignment Procedure" By D.Lee, D.Moon , SK Telecom Seoul , May 2004.IEEE paper File:Minimization of Handoff interruption time optimizing IP Address.pdf
Project Proposal
Our project proposal can be viewed from here. File:Ip handoff proposal.pdf
References
- RFC published by IETF
- IEEE journals
