[JDEV] Presence probe requests

[Richard Dobson]

> > Huh??? But if you are talking about s2s then its not supposed to, in s2s
it
> > is your responsibility to send the unavailable presence of users on your
> > server and if you server goes down, its not something wrong with the
> > protocol its you seeming to not follow it.
>
> I am the person who originally raised this issue for our own custom
> server (http://netwinsite.com/dbabble) that I am implementing the
> Jabber protocol for. But I suspect the person you are replying to here
> is actually referring to jabberd (not his/her own server
> implementation.) From the quick test I ran, it seems jabberd does not
> implement this properly and can easily get the status of users out of
> sync with the transports when the server is restarted.

Sure but thats a problem with an implementation which can be fixed, but as
far as protocol is concerned there isnt really a problem.

> There are also other problems to do with the fact that the Jabber
> protocol was not originally designed to have reliable message and
> status delivery, but rather just intends to achieve message and status
> delivery most of the time. This shows up when a user sends a message,
> and a momentary problem with the network connection between 2 servers
> means that the message is not delivered, but since the Jabber protocol
> was not designed for message receipt acknowledgement the message can
> just disappear with the sender thinking it has been sent, but the
> recipient never actually receiving it. I realize there is a Jabber
> enhancement proposal that suggests a way around this problem
> (http://www.jabber.org/jeps/jep-0040.html). Do any Jabber server
> implementations use this? Our own server protocol is designed to
> ensure message delivery and user status notification is guaranteed in
> all cases, and I find was was quite surprised to find the Jabber
> protocol was never designed to ensure reliable message delivery in the
> first place.

You dont need JEP40 to do reliable message delivery, you can just use the
standard message events this tells you various status's of messages, i.e.
delivered, stored offline, displayed etc.

Richard