TUBA - one of the IPng proposal


Introduction

The proposal for running Internet protocols, the Transmission Control protocol(TCP) and the User Datagram Protocol(UDP), on top of CLNP , is an approach Known as TCP and UDP with bigger addresses(TUBA).


Motivation for TUBA

CLNP and its associated protocols(addressing and routing for the OSI network layer) are mature technologies, for which both router and host implementations already exist in off-the-shelf products from vendors. Furthermore, the CLNP service in the internet is already being deployed by many service providers.

Strategy - dual-stacked network layer

TUBA defines a method for hosts to run Internet transport protocols over a CLNP infrastructure. To achieve this, there are some requirements which must be fulfilled :
Addressing
It is a standard OSI network service access point(NSAP) addresses with a variable length of up to 20 octets, which should accommadate all future addressing needs. It supports multiple address formats. One aspect about OSI addressing that sets it apart from IP addressing is that network addresses are assigned to systems, rather than to interfaces.

CLNP
The datagram protocol at the heart of the TUBA proposal.

Routing
The global routing environment is divided into routing domains of sets of hosts and routers. There are different protocols for routing, interdomain (IDRP), intradomain(IS-IS) and host and router(ES-IS).

Future

Eventually it will be necessary to provide the means for addressing more hosts than is possible with the current version of the IP. OSI NSAP addresses can address a very large Internet. With TUBA it is possible to use the applications and protocols that Internet users currently enjoy, running over CLNP in place of IP. There is also a two-step transition to a TUBA Internet. Initially, IP transit networks add CLNP services, a step that already is in progress by many transit networks. Subsequently, a longer phase where Internet services migrate from using only IP to delivering the same services using both IP and CLNP.