[pulsarpietro]

Due to lack of personal knowledge is not quite clear to me what the problem is with mobile devices. It seems to be the fact that they very often change IP address.

am I right ? Is there any resource you would recommend to make my mind up ?

[mjevans]

That's part of the problem. When the Internet was created computers had finally progressed to being /always on/ and /always connected/; it was possible to relay data (slowly) among these mainframes/big iron machines and have useful and expedient exchange with experts working at other institutions.

That carried forward until the dialup era. At that time the majority of users shifted to being /clients/ that intermittently connected to servers to check their inboxes and sometimes to remote services to request static public content. However they were still in a binary state of online or offline, and when they lost the connection loosing connection was a hard change.

Mobile devices loose connection for other reasons. Mostly the fact that they are wireless. They have limited power, speak across a noisy and highly contended media, and also move around. They are able to poll (somewhat infrequently) but are not always connected. They are in the uncanny valley as hosts; not disconnected enough to warrant a big change of state but also not connected enough to rely on two way communication.

They also happen to be extremely prolific. If not making up a majority of devices that happen to use some services, they are clearly an extremely large market segment. While I find it impossible to create in depth content on them, some do rely upon them as their only computer.

A protocol that is suitable for mobile connections would also alleviate some annoying failure modes caused by ISP maintenance and DHCP lease expiration.