The surprising--and surprisingly quick--success of the iPad may be shaking up the enterprise communications vendors' strategies after all.

Via a site called Wireless Goodness, there seem to be indications that Avaya has been working on a tablet PC. Following the links in their post takes you to an FCC filing that seems to actually center on an application made by Atheros, but in this report, there is indeed a reference to a model "2010-70D01A-003" Avaya tablet PC running as part of a test bed.We haven't talked much about tablets as part of enterprise networks, but maybe we need to start. A few markers we've seen recently:

* This post from Irwin Lazar last week points out the rapid rise of the iPad as an enterprise device.

* HP's purchase of Palm was widely believed to be, at least in part, a component of an impending tablet play.

* Unconfirmed rumors from around the time of the iPad release, suggesting that Cisco was working on a tablet.

So why would Avaya want to have its own tablet? For the last two on our list above, HP and Cisco, a tablet fits a little more clearly into the larger strategy, which is end-to-end.

So one possibility is that Avaya really intends to compete toe-to-toe on end-to-end. That would explain Avaya recommitting to its data product line, instead of shedding it, as many people expected they would when they acquired it as part of Nortel Enterprise.

Frankly, that's the only possibility that makes any sense. If Avaya is building a tablet that's essentially a tablet version of its proprietary desk phones--an Avaya-specific device, optimized for the Avaya platform, if not restricted to that platform--well, that just wouldn't seem to make any sense. Proprietary desk phones can be inflexible devices that hang off a proprietary platform, because they're not going anywhere. Tablets are mobile devices that are supposed to connect to different, often public, networks. Unless Avaya is planning some kind of dual-mode tablet--Avaya-optimized for the office, more generic for the outside world.

It's an interesting play. Overall, maybe it makes sense, insofar as tablets are all the rage while desk phones...aren't. Maybe a tablet is just another form factor of device that a communications vendor like Avaya will need to have on offer.The surprising--and surprisingly quick--success of the iPad may be shaking up the enterprise communications vendors' strategies after all.