[JDEV] Voice over IP

[Mike Prince]

Ok, I'll keep this thread alive a little longer...

> -----Original Message-----
> From: jdev-admin at jabber.org [mailto:jdev-admin at jabber.org] On 
> Behalf Of Jacek Konieczny
> Sent: Thursday, July 24, 2003 12:00 AM
> To: jdev at jabber.org
> Subject: Re: [JDEV] Voice over IP
...
> SIP and H.323 are maybe good for hardware IP phones, but they 
> are no good for usage with IM. 
> 
> For VoIP for IM we need.
> - simplicity (no gatekeeper or separate registar needed to be
>   configured)

SIP doesn't need a registrar or gatekeeper.  One of the reasons I like
it.

I did a lot of SIP work in one of my past lives and it's super simple to
get two clients to talk (sans firewall issues of course)
 
> - NAT-safety. Many IM user are behind various NATs. There is no good
>   solution for this in SIP and H323 protocols, but the 
> problem is being
>   solved for Jabber anyway (for filetransfer) - the solution may be
>   reused for VoIP then. 

SIP can operate over over UDP, TCP, whatever.  Yes, most often it starts
via UDP.

The real problem here is what happens after the session is initiated;
how to we get the voice traffic across the firewall?  RTP is the
prefered transport for a reason, and it doesn't sit well with firewalls.

Good thing about SIP is that it brought heavy-weights like Microsoft
on-board to push home NAT vendors to make devices friendly to software
that needs to get through.  Though it's still a work in progress.  Who
says M$ and it's ilk aren't good for something ;)
   
> - software availability. There is no usable and open source 
> SIP solution
>   for Windows, and there is no good (openh323 is awful and C++) H.323
>   library for Linux. With just RTP it is much better. Client 
> developers
>   would usually have to write their own stuff anyway. Is 
> easier to do it
>   using already implemented XMPP protocol, than to implement another
>   one.

I don't know the current state of SIP clients.  But I still feel working
towards established standards like SIP gives everyone a much greater
chance of interoperability.  Good luck going to a telco/next gen SP and
convincing them to either switch protocols to XMPP or support another
one.  Not likely.
 
> Even choice between H323 and SIP is quite hard - probably we 
> would end with some clients supporting H323, and some client 
> supporting SIP.

Nice thing about standards is that many companies provide gateways
between the two.
 
> And one more thing. The most easy way to use H323 or SIP in 
> Jabber is to use some of available H323 or SIP application. 
> But those applications often already include some kind of IM. 
> So why use Jabber if we need other similar application?

I suspect you're thinking M$'s messenger.  

The challenge is getting service developers to adopt Jabber as their IM
solution.  Unless the app is very simple, new bells and whistles need to
be added to the set of IM capabilities, in which case an open source
solution shines.  Try calling Redmond or Dulles and ask them to hack in
your new feature set, or better yet give you the source code so you can
do it yourself.  Right.


All that said, I hope someone is working on a video/voice XMPP client.
Please tell me so...

-Mike