The accountable of IP Mobility about comes up aboriginal in wireless environments area end users accessories could be affiliated to the arrangement in any cardinal of places. However, the botheration is added accepted that this. A driver train, for example, ability action its riders Internet admission through either active or wireless admission in the car. The alternation could again admission the arrangement through a alternation of radio transmitters amid forth the tracks, behind to a accessory affiliation whenever there is no bounded radio transmitter. This is an archetype of a adaptable network, as against to a distinct adaptable node.
The simplest band-aid to this botheration is to use DHCP and acquiesce the adrift accessories to automatically access new and locally accordant IP addresses for whatever area of arrangement they are affiliated to, as we discussed in Affiliate 20.
The agitation with the DHCP approach, decidedly with adaptable nodes, is that it requires all of the applications on the adrift accessories to bead all of their arrangement connections, access a new abode and potentially new server and area information, and again re-establish communications. This is not consistently convenient.
A adaptable arrangement could, in principle, absorber packets from applicant accessories while accepting an abode for the new arrangement by DHCP. But the time appropriate to get a new DHCP abode and resynchronize acquisition tables is generally far too continued for seamless operation.
The arch case for IP Mobility comes from adaptable accessories such as third-generation cellular telephones. You cannot bead a alarm aback casual from one arrangement arena to the next.
There are two solutions to this problem. The aboriginal is alleged IP Mobility and the second, which has added bound applicability, is Bounded Area Mobility. We will altercate both of these options in this chapter.
IP Mobility, originally authentic in RFCs 2002 through 2006, and adapted in RFC 3344, allows the adrift accessory to use its own "home" IP abode wherever it goes. The abutting hop router on the "foreign" arrangement area the accessory currently finds itself about creates a adit for the adrift device, sending its cartage aback to its appointed "home" router.