VoIP and Presence

Corporate and personal communications is undergoing an obvious revolution right before our eyes. I won’t comment on this aspect of VoIP since there are so many doing so, particularly in the large news publications. However, we’re missing something: presence.

Instant messaging has boomed and become an almost integral part of our society, with youth leading this integration. Have we not noticed that this form of communication is almost entirely controlled by a select few corporations? To name a few:

This is all a Bad Thing™! Lets reminisce for a moment about good, old fashioned, email service. This technology is completely decentralized and relies on each entity having their own SMTP system. If I want to send you mail, I simply do a DNS lookup to find your mail server and off I go. This server can either be provided by your ISP, out-sourced to another provider or you may have set it up internally.

Contrast this with IM, where your messages are being routed by a third-party who:

  • Is not receiving money from you
  • Made you accept a disclaimer that basically guarantees less than nothing
  • Doesn’t really want to interface with the other IM providers

To actually start discussing VoIP now, the above prevents good presence for VoIP applications.

Thankfully, the defacto VoIP protocol, SIP, has full support for an SMTP-like distrbuted model using SRV records in DNS. This allows the DNS system to be queries for the correct SIP server for a domain and therefore gives us nice, convenient addresses for voice communications using the familiar “user@domain” form.

Built on top of SIP, there is SIMPLE or the S I M P L E. This upgrades your SIP infrastructure to support full presence and instant messaging capabilities. So far, I know of very few clients that have full SIMPLE support:

Also, I believe that Microsoft‘s Windows Messenger is available in a SIP edition.

A major open instant messaging protocol, Jabber, also has the above mentioned SRV capability. It seems to be under implemented in practice, however, with many people not even bothering. Jabber uses the XMPP protocol and bridges exist to allow SIMPLE to interoperate with it.

I’m rambling here. To get to the point, it seems that integrating SIP hardware devices : Analog Telephone Adapters (ATAs), like those from Sipura, and desk phones like those from Polycom; with presence provided either by SIMPLE or XMPP, is a problem. See, when you are using a great hardware phone for actual calling, you can’t do decent presence. How will my Jabber client know that I’m on the phone in order to set my status to “On the phone”?

My conclusion is that we should really be using softphones. Why not? Don’t we all have laptops and Bluetooth headsets? :-) Well, I intend to get myself fully setup this way. To heck with all the other ways of getting voice service. Also, Jabber isn’t a great candidate unless you use something like the myJabber Instant Messaging Client for XMPP and myJabber AE Soft Phone combination, which is non-standard.

More to come on this topic once I get a copy of eyeBeam for Mac OS X to play with.

One thought on “VoIP and Presence

  1. Dave

    What are the “[SRV][srv]” entries? Also.. I agree that we should be one with the phone, via all sorts of integration, but I think you meant “On the phone.”

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