Presentation on theme: "Mobile IP.. 45-7028-115-6. How Mobile IP Works? Agenda What problems does Mobile IP solve? Mobile IP: protocol overview Scope Requirements Design goals."— Presentation transcript:
How Mobile IP Works?
Agenda What problems does Mobile IP solve? Mobile IP: protocol overview Scope Requirements Design goals Functional entities Q & A
What Problems Does Mobile IP Solve? An IP address not only identifies a host but also a point-of-attachment. Host-specific routes approach suffers from serious scalability, robustness and security concerns if applied to the global Internet.
What Problems Does Mobile IP Solve? (continued) A host cannot change its IP address without terminating on-going sessions and restarting them after it acquires a new address. Other link layer mobility solutions exist but are not sufficient enough for the global Internet.
Mobile IP: Protocol Overview
Scope Mobile IP is a network layer solution for homogenous and heterogeneous mobility on the global Internet which is scalable, robust, secure and which allows nodes to maintain all ongoing communications while moving.
Requirements MN must be able to communicate with other nodes after changing its LL POA. MN must be able to communicate using only its home (permanent) IP address regardless of its current LL POA.
Requirements (continued) MN must be able to communicate with other nodes that do not implement Mobile IP mobility functions. MN must not be exposed to any new security threats over and above those which any fixed node on the Internet is exposed to.
Design Goals Mobile IP was designed to make the size and the frequency of required routing updates as small as possible. It was designed to make it simple to implement mobile node software. It was designed to avoid solutions that require mobile nodes to use multiple addresses.
Functional Entities Mobile Node (MN): a node which can change its POA while maintaining any ongoing communications and using only its home(permanent) IP address. Home Agent (HA): a routerwith at least one interface on the MNs home linkwhich: MN keeps informed of its current location, i.e., its care-of-address(COA), intercepts packets destined to the MNs home address and tunnels them to the MNs current location (or COA).
Functional Entities (continued) Foreign Agent (FA): a router on a foreign linkwhich: assists the MN in informing its HA of its current COA, sometimes, provides a COA and de-tunnels packets for the MN, acts as the default router for packets generated by the MN while connected to this foreign link.