Hi,
I am student and new to the Presence Model und Protocols.
I have in my student project the following scenario:
company A wants to develop a presence service PA. The presence service PA should get the data from the presence server PB of an other Company B over the Internet. The Presence information of PA should be made available in the Company A for different applications.
my question: can PA poll or subscribe all changed/updated Presence Information from PB regularly. Or it should request the Presence Information of each Presentity individually?
which Presence server can implement the presence service PA. What should I do if PB uses another Protokoll?
Thank you and Best Regards Koder
cherami@gmx.de wrote:
Hi,
I am student and new to the Presence Model und Protocols.
I have in my student project the following scenario:
So, one task in this project would be to figure out the details by yourself, right? As a starting point, you should gather some material about distinct presence protocols and learn how these protocols work·
company A wants to develop a presence service PA. The presence service PA should get the data from the presence server PB of an other Company B over the Internet. The Presence information of PA should be made available in the Company A for different applications.
my question: can PA poll or subscribe all changed/updated Presence Information from PB regularly. Or it should request the Presence Information of each Presentity individually?
Most "real" presence protocols such as SIP-based presence (sometimes referred to as "SIMPLE") and XMPP at least allow for individual subscriptions as well as so-called subscriber lists.
One of the problems with this kind of application is the overhead from presence messages, especially when using SIP. Therefore, XMPP might be a better choice for your specific application since it can provide for confederations of presence servers over a more efficient communication channel.
which Presence server can implement the presence service PA.
SER could do this for SIP-based presence (including resource subscription lists), ejabberd could be used for XMPP.
What should I do if PB uses another Protokoll?
You would have to use a protocol gateway. Look at the presence-related SER documentation to learn how this works.
HTH, Olaf
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?
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.
Best Regards Koder
-------- Original-Nachricht -------- Datum: Thu, 16 Aug 2007 09:53:04 +0200 Von: Olaf Bergmann Olaf.Bergmann@freenet-ag.de An: cherami@gmx.de CC: serusers@lists.iptel.org Betreff: Re: [Serusers] presence server 2 presence server
cherami@gmx.de wrote:Hi,
I am student and new to the Presence Model und Protocols.
I have in my student project the following scenario:
So, one task in this project would be to figure out the details by yourself, right? As a starting point, you should gather some material about distinct presence protocols and learn how these protocols work·
company A wants to develop a presence service PA. The presence service PA should get the data from the presence server PB of an other Company
B
over the Internet. The Presence information of PA should be made available in the Company A for different applications.
my question: can PA poll or subscribe all changed/updated Presence Information from PB regularly. Or it should request the Presence Information of each Presentity individually?
Most "real" presence protocols such as SIP-based presence (sometimes referred to as "SIMPLE") and XMPP at least allow for individual subscriptions as well as so-called subscriber lists.
One of the problems with this kind of application is the overhead
from presence messages, especially when using SIP. Therefore, XMPP
might be a better choice for your specific application since it can provide for confederations of presence servers over a more efficient communication channel.
which Presence server can implement the presence service PA.
SER could do this for SIP-based presence (including resource subscription lists), ejabberd could be used for XMPP.
What should I do if PB uses another Protokoll?
You would have to use a protocol gateway. Look at the presence-related SER documentation to learn how this works.
HTH, Olaf
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
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cherami＠gmx.de -
Olaf Bergmann