Hi Cameron, On Sun, 2011-11-06 at 21:31 -0800, Cameron Byrne wrote:
There are a variety of reasons. Most prominent is that if the issue is lack of IPv4 addresses (public and private), dual-stack does not solve this problem, each device still gets an IPv4 address. Another major issue is that in GSM/UMTS (3GPP pre-release 9), having dual-stack means having 2 attachments to the network, one for v4 and one for v6. Most mobile providers pay for most of their network kit in terms of these attachments known as PDP. Consequently, dual-stack doubles the of the packet-core network. If we take the licensing and contractual parts out of the equations, double the attachments means double the signalling and mobility events ... resulting in double the CPU / Memory / blah ...
That'll probably explain it... Thanks. :)
LTE does not have the dual attachment problem since there is the concept of having v4 and v6 in one attachment, but it does not change the fact that there are not enough IPv4 addresses to go around, especially from a strategic planning perspective (let's design this once for 5 to 10+ year life ...)
If only the UK was as far ahead on LTE as the US! Tom