[Serusers] Instant Messaging User Agent Interoperability problem

[Klaus Darilion]

Victor Huertas Garcia wrote:
> 
> 
> Hi all,
> 
> I am testing the Instant Message Service with the SER v0.8.14 and I see 
> that it routes them correctly towards the destination user agent. 
> However, what I have seen is a tremendous imcompatibility between user 
> agents of different vendors.
> 
> Here just a bit of this:
> 
> IM between two Windows Messenger 4.7.
> 
> What I see it that the very first MESSAGE in the conversation is sent 
> towards the SER and it routes it perfectly but the subsequent MESSAGES 
> are exchange between both Messengers directly!!! It is weird... but this 
> is how it is working.
> 
> IM between Window Messenger 4.7 and EyeBeam v1.1
> 
> The EyeBeam always send the MESSAGES towards the SIP proxy and messenger 
> receive them with no problem. However, when the messenger tries to send 
> a MESSAGE in the conversation it even doesn't send the packet (I tried 
> to capture it with Ethereal and no packet was sent at all) and 
> subsequently tell you that the text message could not be delivered to 
> the destination.
> 
> IM between EyeBeam v1.1
> 
> No problem at all.
> 
> IM involving Windows Messenger 5.1
> 
> This version of messenger sends an INVITE to the destination before 
> issuing the MESSAGE. With EyeBeam is a total disaster and the 
> comunication is not possible.
> 
> 
> My conclusion is that the SER has not implication in such 
> incompatibility at all and that is a matter of interoperability among 
> vendors and different implementations of SIMPLE. Do you agree?

Correct!

Some notes: WM 4.7 replies with a Contact: header in the 200 OK to 
MESSAGE. This is not allowed according to the MESSAGE RFC, but WM uses 
this contact for further messages to this user. I think you can bypass 
this problem by using record_route.

WM 5.1: You can force WM 5.1 to fall back to "old mode" by catching the 
INVITEs in ser and reply with 4xx. But 5.1 wont accept MESSAGE without 
prior INVITE :-(

regards,
klaus