SIPP Overview
SIPP is a new version of IP which is designed to be an evolutionary step
from IPv4. It is a natural increment to IPv4. It can be installed as a
normal software upgrade in internet devices and is interoperable with the
current IPv4. Its deployment strategy is designed to not have any
flag days or other dependencies. SIPP is designed to run well on high
performance networks (e.g. ATM) and at the same time is still efficient
for low bandwidth networks (e.g. wireless). In addition, it provides a
platform for new internet functionality that will be required in the near
future.
SIPP is designed to be the successor to IPv4 and is assigned IP version
number 6. It was not a design goal to take a radical step away
from IPv4. Functions which work in IPv4 were kept in SIPP. Functions
which didn't work were removed. The changes from IPv4 to SIPP fall
primarily into the following categories:
- Expanded Routing and Addressing Capabilities
-
SIPP increases the IP address size from 32 bits to 64 bits, to
support more levels of addressing hierarchy and a much greater
number of addressable nodes. SIPP addressing can be further
extended, in units of 64 bits, by a facility equivalent to IPv4's
Loose Source and Record Route option, in combination with a new
address type called "cluster addresses" which identify topological
regions rather than individual nodes. The scaleability of
multicast routing is improved by adding a "scope" field to
multicast addresses.
- Header Format Simplification
-
Some IPv4 header fields have been dropped or made optional, to
reduce the common-case processing cost of packet handling and to
keep the bandwidth cost of the SIPP header almost as low as that of
IPv4, despite the increased size of the addresses. The basic SIPP
header is only four bytes longer than IPv4.
- Improved Support for Options
-
Changes in the way IP header options are encoded allows for more
efficient forwarding, less stringent limits on the length of
options, and greater flexibility for introducing new options in the
future.
- Quality-of-Service Capabilities
-
A new capability is added to enable the labeling of packets
belonging to particular traffic "flows" for which the sender
requests special handling, such as non-default quality of service
or "real-time" service.
- Authentication and Privacy Capabilities
-
SIPP includes the definition of extensions which provide support
for authentication, data integrity, and confidentiality. This is
included as a basic element of SIPP.
For more information on SIPP see the
SIPP Protocol Specification
and the
SIPP Routing and Addressing Specification
.