http://www.raleigh.ibm.com/tr2/tr292003.ps
The popularity of wireless communications has underscored the need for a standardized set of Network layer protocols that allow mobile computers to access the Internet from various points of attachment without the need for user intervention or system reconfiguration: that is, support for mobility must be provided. This paper discusses two protocols being developed to address this need:
The CDPD Forum, a trade association of carrier, equipment suppliers, and application developers, has specified a set of mobility-enabling protocols for use in the Cellular Digital Packet Data networks that are now being deployed nationwide by cellular carriers. The CDPD Forum recently published their revised specification: CDPD Specification, Version 1.1; January 1, 1995.
The Mobile-IP Working Group of the Internet Engineering Task Force has also developed a set of mobility-enabling protocols. Currently, this work is at the level of an Internet Draft, with plans to have it accepted as an RFC by year end 1995. The most recent version of this specification is: IP Mobility Support; Internet Draft; January 4, 1995, C. Perkins (editor).
Mobility support is provided by new protocols that complement the existing IP protocol and its associated intra- and inter-domain routing protocols. This paper describes the constituent functions of each approach, outling their strengths and weaknesses. It discusses basic methods, network management support, and conformance issues. It briefly touches on additional mobility support functions offered by the respective protocols. Finally, it discusses unification between the CDPD and Mobile-IP approaches.
Triangular routing is the basic approach used in both CDPD and Mobile-IP. Since this has been the subject of much discussion and debate, Appendix A presents the author's views on the topic.