cherami@gmx.de wrote:
Hi Olaf,
I understand that a client must/can subscribe to an other client to get notifications of his status.
But can a presence server do something like that? Can a presence server subscribe to other clients?
2 x yes.
The Idea is, that I have in my organisation Clients, that only needs the presence information of other clients in other organisations. So I want to cache/mirror in my server the presence information ot the clients ot the other organisation, so that I do need to connect the server ot the partners for each request from the clients of my organisation.
Sure, this is possible. For example, content networks for WWWW traffic work this way, and there is no reason why not doing the same for presence subscriptions (well, there are some pitfalls due to the persistent nature of presence subscriptions). Look into the SER-based presence gatewaying scenarios to learn how presence subscriptions can be relayed from a local domain to some other server and vice versa. There is no magic in it but just putting things together.[1]
[1] As I said before, I do not recommend doing this because of the message overhead it generates. If you have both servers under control, you could invent a more efficient protocol for passing inter-domain presence information.
Best regards, Olaf