We are facing the exhaustion of the IANA IPv4 free IP address pool.
Unfortunately, IPv6 is not yet deployed widely enough to fully
replace IPv4, and it is unrealistic to expect that this is going to
change before the depletion of IPv4 addresses. Letting hosts
seamlessly communicate in an IPv4-world without assigning a unique
globally routable IPv4 address to each of them is a challenging
This draft proposes an IPv4 address sharing scheme, treating some of
the port number bits as part of an extended IPv4 address (Address
plus Port, or A+P). Instead of assigning a single IPv4 address to a
single customer device, we propose to extend the address field by
using bits from the port number range in the TCP/UDP header as
additional end point identifiers, thus leaving a reduced range of
ports available to applications. This means assigning the same IPv4
address to multiple clients (e.g., CPE, mobile phones), each with its
assigned port-range. In the face of IPv4 address exhaustion, the
need for addresses is stronger than the need to be able to address
thousands of applications on a single host. If address translation
is needed, the end-user should be in control of the translation
process - not some smart boxes in the core.
Working Group Summary
This document is not the product of a working group.
- Are there existing implementations of the protocol?
Yes, one (ISC AFTR A+P support), but without dynamic port allocations and
no stateless support. Other implementations to follow, one of obstacles is
current status (draft).
- Have a significant number of vendors indicated their plan to implement
Iskratel, possibly Cisco and Juniper.
- Are there any reviewers that merit special mention as having done a
thorough review, e.g., one that resulted in important changes or a
conclusion that the document had no substantive issues?
All last version thorough reviewers are now among authors:
Mohammed Boucadair (FT)
Reinaldo Penno (Juniper)
Ron Bonica is document shepherd