Mobile Users: Invisible to Presence?Mobile Users: Invisible to Presence?

What if a mobile worker initiates a call on their mobile phone to someone outside the company? The system has no way of knowing, and presence status doesn't change.

A lot of the talk and demos at Lotusphere this past week were about presence, and the great value this offers when integrated with communications portals and interfaces. I'll take the value of presence as stipulated, but there's one important exception, a scenario where you can't get presence.Most of the UC systems, certainly the Sametime Unified Telephony that IBM Lotus was showing off this week, can display the presence of any user connected to the system--in the case of SUT, even indirectly, because SUT acts as middleware so that a user on a Cisco IP-PBX can see the presence status of a colleague on an Avaya IP-PBX, with SUT brokering in the middle.

These systems also do a great job getting a call to the device that the person is actually using at the time; various systems can ring your office phone, cell phone, home phone, and hotel extension, either concurrently or in succession, until you pick up or it goes to a mailbox per your preset rules.

(Incidentally, at Lotusphere I heard a wonderful put-down of "forking," which is where all the devices are rung at the same time and the first one that's picked up gets the call. Jeremy Sussman, who's IBM Lotus's lead architect for Sametime Unified Telephony, likened this approach to being in a clock store at noon, with all the cuckoo clocks and others going off all at once. For you old folks, think of the beginning of that Pink Floyd song, "Time.")

But here's where presence comes up short: You can extend the call to an employee's mobile phone, and if an incoming call is routed into the call server and thence out to the cell phone, that person, if they answer the call, will switch to "on-the-phone" presence status in their colleagues' UC portals.

But what if that mobile worker initiates a call on their mobile phone to someone outside the company? It's been known to happen.

In that case, the system has no way of knowing that the person is on the phone, and their presence status doesn't change.

This problem actually came up at Lotusphere, in a session on SUT that was being run by Jeri Korkki of IBM Global Technology Services. His suggestion was that the mobile operators would need to be able to pass on-hook/off-hook status to enterprise systems. Yeah, good luck with that.

There is another alternative. If the person's mobile device has the UC client on it, the user could signal the call server to set up one leg of a call out to the user's cell phone, then the other leg of the call out to the person that the user is trying to reach. Then the call server would know the mobile user's status and could reflect it.

All of this may seem like a minor detail, but ask yourself: If presence is the dialtone of the future, what if dialtone and busy signals couldn't be relied on to reflect the true status of a person on a traditional call? What if you called someone and got a busy signal even though they were sitting there, waiting for your call? What if you picked up your phone and got dialtone even though the system, in fact, was down?What if a mobile worker initiates a call on their mobile phone to someone outside the company? The system has no way of knowing, and presence status doesn't change.