(no subject)

This paper proposes a novel approach for Internet host mobility using
dynamic updates to the DNS to track host location. This paper tries
to build an end-to-end architecture for host mobility that makes no
changes to the underlying IP communication substrate.
There are three important components in the system: addressing,
mobile host location, and connection migration. The system removes
the need for an additional home-agent to broker packet routing. The
DNS already provides a host location service, and any further control
is managed by the communicating peers themselves, triggered by the
mobile host when it changes network location.
Unlike Mobile IP, in a foreign network, a mobile host uses a locally
obtained interface address valid in the foreign domain as its source
address while communicating with other Internet hosts. If the mobile
host were to move to another network attachment point during a
connection, a new address would be obtained. If a mobile host were
always a client, then no updates need to be made to any third party
such as a home agent or the DNS. To support mobile servers and other
applications where Internet hosts actively originate communication
with a mobile host, they use the DNS to provide a level of
indirection between a host's current location and an invariant end-
point identifier. It takes advantage of the fact that a hostname
lookup is ubiquitously done by most applications that originate
communication with a network host, and use the DNS name as the
invariant. The scaling problem could be solved by selecting the TTL
to be zero.
When the mobile host move to another network attachment point during
a connection, the current connection would continue seamlessly via a
secure negotiation with the communicating peer. It uses a set of
connection migration options to securely and efficiently negotiate a
change in the IP address of a peer without breaking the end-to-end
connection. The security of this approach is based on a combination
of the well-documented secure DNS update protocol in conjunction with
a new secure connection migration mechanism.
The architecture allows end systems to choose a mobility mode best
suited to their needs. Routing paths are efficient with no triangle
routing, and any connection involving the mobile host shares fate
only with the communicating peer and not with any other entity like a
home agent.
This paper is a research work with originality. As the authors say in
the paper, The general idea of using names as a level-of-indirection
to handle object and node mobility is part of computer systems
folklore. But for some years, this paper seems the first one to give
the approach systematically. However, there still are some question
which confuse me.
When a mobile host moves to anther network, it should update the
hostname-to-address mapping in the DNS. As mentioned in the paper, if
the mobile host that makes frequent moves, DNS should be updated
frequently. Is it efficient? Will it cause some other problems? If
the mobile host move frequently, will it cause the failure of TCP
connection migration?
Another problem is that it seems we should modify the transport layer
protocol when implementing the TCP connection migration. Does it cost
enough? Authors do not give us an analysis.
Received on Tue Oct 17 2006 - 22:19:00 EDT