IM Gateway - capabilities and limitations - v1.0
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The gateway allows the message passing between SIP users and other
IM users (ICQ, AIM, Yahoo ...).

IM Gateway uses for this a Jabber server which has the facility of supporting
many IM protocols (they are called IM transports). So, in fact, the gateway is
between SIP and Jabber.

Because the most of the IM protocols are not open source and they are the
property of some companies, Jabber does not provide full support for these
protocols. From time to time, the owner of the protocol changes the protocol
structure, and for a while, that transport is no longer available. There are 
some guys doing some kind of reverse engineering on these protocols. But not
whole protocol structure is discovered, each transport has its own limitations.

In additions, many of the IM native clients allow only one user to be online at
a moment, and IM servers could easy say that the hosts which have more than one
open connection are not using a native client and block those addresses or the
accounts.

Next, are presented the IM transports that are running on our Jabber server, or
they are wanted to be available. The capabilities and limitations are what can
be found on the net about transports.


AIM transport
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It is only one well known version of aim-transport.
(web location: http://aim-transport.jabberstudio.org/)
AIM-t provides basic interoperability between Jabber and AIM/ICQ network.
Currently AIM-t is undergoing massive changes. It will be a standalone component
once this is finished.

* capabilities
- currently supporting basic presence and messaging.
- reliable messaging (via server only)
- simple user info retrieval (ICQ only)
  may take some time, just wait...
- SMS sending (ICQ)
  send "SEND-SMS:number:text" to any ICQ user, for example
  "SEND-SMS:+4917012345:Test"
- away message retrieval (AIM only)
- offline messages (ICQ only)

* limitations
- NO file transfer
- NO multichat
- NO user search
- NO incoming SMS
- NO import of server buddy lists
- NO handling of incoming ICQ auth requests
- ICQ messages may get dropped by AOL servers if your contact uses an old
  ICQv5 client.


ICQ transport
-------------
Excepting the AIM transport, there exists another distribution for ICQ
transport.
(web location: http://icqv7-t.sourceforge.net/)

* capabilities
- messaging (through server only)
- presence notification
- SMS support

* limitations
- no file transfer

The AIM transport for ICQ.
- see AIM transport

A new versions of ICQ transport seems to be available now. But now place from
where it can be downloaded - I sent a mail asking for a distribution.

A short description can be found at
http://mailman.jabber.org/pipermail/jdev/2002-July/012343.html


IRC transport
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(web location: http://download.jabber.org/contrib/irc-transport.tar.gz)
This version of IRC transport is a beta version

* capabilities
- It will connect to irc servers and allow you to talk to them, but it is still
  in heavy development

* limitations
- private messaging does not yet function
- transport registration/notify will not be supported
- groupchat 1.0 and 1.1 will not be supported in favor of the 2.0
  iq:conferenec/iq:browse protocol you will be able to log into and create
  password protected groups now (although this may not work yet)
- there still may be some other bugs but they aren't caught yet.
- in testing, it has been fairly stable, although some functionality may
  not be there yet.
- requires jabberd version 1.4 several functions used, including MIO,
  MTQ, and xhash functions were not available in previous jabber server
  versions


MSN transport
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(web location: http://msn-transport.jabberstudio.org/)
* capabilities
- provides basic interoperability between Jabber and MSN (messaging/presence)
* limitations
- there are memory leaks in MSN-t so is better to be run in a seperate process
  and restart it from time to time
- MSN-t uses TCP port 1863 for incoming connections so you have to open this
  port if you use a firewall.
- the other parts excepting messaging/presence

Yahoo transport
---------------
(web location: http://yahoo-transport.jabberstudio.org/)

As of 2002-07-10 this transport has ceased functioning (probably due to YIM
 protocol changes).
The transport is being worked on - see JDEV mailing list :
http://mailman.jabber.org/pipermail/jdev/2002-July/012327.html

* capabilities
- log into Yahoo Messenger server, and send/recv messages.
* limitations