Define a Network of SDN users , and check who is connected for chat.

Not sure what you expect here. Can you please elaborate? What are you missing from a functional perspective, or what do you want to see?

What don't you understand? It's so evident: it would be easy to chat with expert about particular problem if he is ready to chat.

Chat is limited by design to those people one follows and who follow you. It is up to the expert to decide to follow you. The goal is public discourse so that solutions to the posted problems are visible to all, not private discussions except where proprietary information is absolutely necessary to share. You have the option to paste a link to said experts into your posts to bring it to their attention. However their participation is strictly voluntary (as is majority of the member involvement in this community). There are very few people whose job responsibilities make SCN participation mandatory and there are no SLAs for responses. SCN is a not just a social/technical exchange network. It is a repository of hundreds of thousands of solutions to previously solved problems. So we want to continuously expand that repository for all to benefit.

There is one aspect of SCN that many folks do not really understand, especially when they first join. While you can open a ticket and expect some level of responsiveness based on SAP's commitment to a service level, SCN is a collaborative environment. It tends to keep the communications professional and reasonably friendly. A ticket, by its very nature, is a bit more confrontational. I think most members prefer to find their solutions through this community and only open tickets when absolutely necessary. However, it does not mean that every post will receive a solution or even a response. It is all voluntary, though Moderators and many other SAP employees will often intervene when a question does not generate a response. Mostly this is an issue with poorly worded or insufficient information in the problem's description. Sometimes, it is just missed.

Hope this helps your understanding of how SCN works.

Cheers, Mike (Moderator)

SAP Technology RIG

The functioning of SCN is quite clear, but that don't contradict with the idea of chat. Check SO implementation. Joining chat is always voluntarily but nevertheless those who are ready to help always can help.