I don't know, i always thought that the box had to 'check in' every now and then and updates always came that way??
If you have SKY multiroom (now called multiscreen) you must keep all boxes connected to the phone otherwise you do not.
If you wish to use the interactive facilities (view SKY bills etc) it needs to be connected. Very, very, very few people use this.
Software updates have always been dellivered over the satelilte link.
Authorisation / ordering of pay per view items used to be solely over phone line. However with the latest version of software and a 890 or 895 SKY box pay per view works over the network (provided the box is connected to the internet so that on-demand is working).
BT Infinity 2 - IP profile 77 / 20 - super fast!
Previously BE Unlimited - 21,000 Download 1,200 Upload but then moved house - 6,500 Down, 1Mb/s up - gutted!
Ex <n>ildram , been to SKY MAX - 15,225 Download