Method and system for support of overlapping IP addresses between an interworking function and a mobile IP foreign agent

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to the figures, wherein like reference numerals represent like elements in all of the several views, FIG.
1 illustrates, by way of additional background, the prior art wireless data network scheme described above wherein data packets are transmitted between mobile nodes and their corresponding Home Agents.
More particularly, in the wireless data network scheme shown in FIG.
1, a mobile node (MN.
sub.
1,1, MN.
sub.
1,2, MN.
sub.
2,1, or MN.
sub.
2,2) can be a separate mobile device, such as a mobile phone, which is equipped with radio equipment (e.
g.
, MN.
sub.
1,1, MN.
sub.
2,1, and MN.
sub.
2,2), or a mobile device connected to another computing device, such as a laptop or notebook computer (e.
g.
, MN.
sub.
1,2).
Mobile nodes MN.
sub.
1,1, and MN.
sub.
1,2 are associated with a private IP network 1 offering Mobile IP service with a Home Agent HA.
sub.
1 that communicates with a public portion of the data network via an Ethernet card ETH 1 that is assigned a public IP address.
Similarly, mobile nodes MN.
sub.
2,1 and MN.
sub.
2,2 are associated with a private IP network 2.
The IP network 2 has its own Home Agent (HA.
sub.
2) that communicates with the public portion of the data network via an Ethernet card ETH 2 that is also assigned a public IP address.
Furthermore, mobile nodes MN.
sub.
1,1, MN.
sub.
1,2, MN.
sub.
2,1, and MN.
sub.
2,2 have home (IP) addresses IP.
sub.
11, IP.
sub.
12, IP.
sub.
21, and IP.
sub.
22, respectively.
The home addresses IP.
sub.
11 and IP.
sub.
12 must be different because they are associated with the same private network.
Similarly, IP.
sub.
21 and IP.
sub.
22 must be different addresses.
It is possible, however, that one of the home addresses in the first private network (e.
g.
, IP.
sub.
12) is identical to one of the home addresses in the second private network (e.
g.
, IP.
sub.
21).
As shown in FIG.
1, when a mobile node is away from its associated private IP (home) network, the network that serves the node is called the visited network.
A data packet transmitted in the reverse traffic direction travels from a mobile node MN