SIP protocol & Provider Implementation for ECF under Eclipse Public License
Eclipse Communication Framework is consists of several messaging protocol such as XMPP, MSN, Yahoo & IRC. There are providers plugged in to the Eclipse for these protocols at the moment. But there is no successfully working SIP Provider for ECF yet. So the aim of this project is to integrate a successful SIP provider to ECF. During the project SIP protocol will be implemented under Eclipse public License as most of the existing SIP implementations are under GNU GPL or Commercial License which are incompatible with EPL.
The project consists of 3 major tasks:
- Studying the protocol
- Implementing the protocol
- Implementing the ECF provider
The first task, studying the protocol can be challenging. To accomplish this, there are a few methods available:
- Reading online articles/blogs which describe the protocol
- Black-Box testing – this can be done by doing various activities (Login, Logout, Sending instant messages etc) and observing the underlying requests made and responses arrived. For observing requests and responses, a network protocol analyzer can be used. There are several such open source protocol analyzers available at the moment.
- Examining the existing open source Yahoo protocol implementations.
In addition to these methods, some other controversial methods like reverse engineering the code of the client/ assembly level debugging are also available. I do not intend to use such methods for this project.
Out of the above 3 methods, I plan to use (1) and (2) as appropriate for studying the protocol. Also, there is a possibility of using (3) if there are BSD-style licensed implementations available. However, the most popular ones are under GPL, so I plan to study the protocol without depending on this method.
First step will be to read online articles and get an overall idea of the protocol. Then for each activity supported by the protocol (i.e. Login, IM, Add/Remove contacts etc), I will study the underlying requests responses closely by reading the articles. Then validity of what I study needs to be recognized by using either black-box testing or writing a simple program to do the request. In case when information I’ve collected are out-of-date or invalid, black-box testing will be used for observing several requests/responses. Using these observations, protocol can be studied. This procedure will repeatedly apply to study all portions of the protocol I’ll be implementing.
My plan is to carry out both the tasks , studying and implementing the protocol, simultaneously as appropriate, rather than two sequential separate tasks.
After testing the implementation, ECF provider will be implemented. For this task, one of the existing provider implementations such as XMPP or MSN can be taken as a reference.