Q: When trying the B2BUA sample application and send an INVITE message, I get a 404 reply instead of 200. Why?

A: There is a mistake in the servlet code and some provisioning is missing.

Solution:

1. Import the B2BUA for JSR116 project.
2. In the Provisioning perspective, add a PSI with the value sip:b2buasample@ericsson.com. Assign it to the default "Profile" service profile.
3. Add an Initial Filter Criteria for this new URI:
    a) Click the iFC Tab
    b) Add a new iFC and name it B2BUA.
    c) Accept the default values in the remaining fields and save. 
4. Add an Service Point Trigger:
    a) Click on the Service Point Trigger tab.
    b) Add a new SPT.
    c) In the trigger definition part, set the trigger type to Request URI.
    d) Set the Request URI value to sip:b2buasample@ericsson.com and save.
5. Click on the Service Profile tab and add the B2BUA to the "Profile" service profile. 
6. Update the servlet code to replace the line

request.getSession().setHandler("B2BUAServlet");

with

request.getSession().setHandler("B2BUAServletJSR116");

    7.   Restart the CSCF.

    8.   Run the ATF script.

Q: I don’t know about IMS or SIP, where do I get started?

A: You can register for a training and use online resources to get knowledge on IMS and SIP.

Solution: Please see the following resources:

Ericsson SIP and IMS Training:

• Consult the training catalog here (look for the IMS Section): http://www.ericsson.com/solutions/learning/find_training.shtml 
• Contact Ericsson Training Center in your area: http://www.ericsson.com/solutions/learning/education_centers.shtml

General IMS information and training

• On Wikipedia: http://en.wikipedia.org/wiki/IP_Multimedia_Subsystem     
• On the IMS Developer site: http://www.ims-developer.org/content/view/42/54/     
• IMS Forum ("Education"): http://www.imsforum.org/education

SIP Specific information

• On Wikipedia: http://en.wikipedia.org/wiki/Session_Initiation_Protocol     
• Tech invite has plenty of useful info: http://www.tech-invite.com/     
• This third party site offer SIP training: http://www.sipknowledge.com/elearn.html     
• Sip Forum: http://www.sipforum.org/content/view/22/199/

Suggested SIP / IMS  readings

• The 3G IP Multimedia Subsystem (IMS): Merging the Internet and the Cellular Worlds by Gonzalo Camarillo (Author), Miguel-Angel García-Martín (Author)     
• The IMS: IP Multimedia Concepts and Services by Miikka Poikselka, Aki Niemi, Hisham Khartabil, and Georg Mayer     
• IMS Multimedia Telephony over Cellular Systems: VoIP Evolution in a Converged Telecommunication World by Shyam Chakraborty, Janne Peisa, Tomas Frankkila, and Per Synnergren     
• The IP Multimedia Subsystem (IMS): Session Control and Other Network Operations by Travis Russell     
• Internet Multimedia Communications Using SIP: A Modern Approach Including Java Practice (The Morgan Kaufmann Series in Networking) by Rogelio Martinez Perea     
• Internet Communications Using SIP: Delivering VoIP and Multimedia Services with Session Initiation Protocol (Networking Council) by Henry Sinnreich and Alan B. Johnston     
• SIP: Understanding the Session Initiation Protocol, Second Edition by Alan B. Johnston     
• SIP Demystified by Gonzalo Camarillo     
• SIP Beyond VoIP: The Next Step in the IP Communications Revolution by Henry Sinnreich, Alan B. Johnston, Robert J. Sparks, and Vinton G. Cerf     
• Session Initiation Protocol (SIP): Controlling Convergent Networks by Travis Russell     
• SIP/IMS standard view: SIP IMS Specifications For Dummies" by Solomon Berliner (self published by sipknowledge, http://www.sipknowledge.com/eBooks.htm)