1. 2009 IEEE International Advance Computing Conference (IACC 2009)
Patiala, India, 6–7 March 2009
An Overview of Study on Smooth Porting
process scenario during IPv6 Transition
(TIPv6)
Hanumanthappa. J Dr.Manjaiah.D.H. Thippeswamy.K
Lecturer, Reader, Assistant Professor & HOD
Department of Studies in Computer Department of Computer Science Dept. Information Science & Engineering
Science University of Mysore, Mangalore University, R.L.Jalappa Institute of Technology
Manasagongotry, Mysore, Mangalagangothri, Mangalore, Kodigehalli, Doddaballapura
Karnataka, INDIA Karnataka, INDIA Bangalore Rural District , Karnataka, INDIA
Email:- hanums_j@yahoo.com Email:- ylm321@yahoo.co.in Email:- thippeswamy_yadav@yahoo.co.in
Abstract - Deploying IPv6 may seem a complex and forward, and ideas to simplify the transition between
expensive operation, however careful planning and the two versions have to be standardized. Today’s
choosing the right techniques actually make the almost existing applications are written assuming
transition to IPv6 smooth and easy. This document IPv4.Only very recently IPv6 has been taken into
illustrates different strategies used for IPv6 network account. The aim of this paper is to provide general
transition and some specific tools with their recommendations to be taken into account during the
respective strengths and weaknesses. In the last five porting process of applications and services to IPv6.
years, the Internet has transformed the way people This will create an opportunity to developers to move
live. The Internet’s tremendous growth rate greatly smoothly their applications into the new
exceeded any futurist’s predictions, including the environment.
Internet Protocol (IP) architect’s plans from twenty
One of the key features of IPv6 is Porting
years ago. IP version 4 (IPv4) provided ample
process. The deployment of this new protocol brings
addresses for network growth throughout the 1980s,
set of new challenges to the application developers
but the address-supply is now low outside the United
and application service providers. Currently many
States. If current Internet growth rates continue, the
vendors and manufacturers and internet service
prediction is that the supply of unassigned IPv4
providers are working hard to provide IPv6
addresses will be depleted within ten years. Internet
connectivity and support for the users. The transition
Protocol Version 6 (IPv6) overcomes many
phase from IPv4 to IPv6 has raised many discussions
limitations of IPv4.The aim of this paper is to provide
among the internet community, as a lot of companies
general recommendations to be taken into account
and network demonstrators are reluctant, facing what
during the porting process of applications and
they perceive face as a great challenge with large
services to IPv6.
costs. Apart from the network and hardware part of
Keywords: Any cast, Broadcast, IPv4 Transition, the issue, a very well known important aspect is the
IPv6 Transition, Multicast, Uni cast. transition (modification) of existing applications so
that they become IPv6 enabled .The problem of
1. INTRODUCTION
transition existing applications to IPv6 has been so
The rapid growth in the number of handheld devices far addressed by several researchers including
and protocols putting a strain on the current IP companies and academic institutes. The majority of
protocol (IPv4), which is not being able to keep pace network applications in existence today presume the
with the increasing demands brought about by the use of the IPv4 protocol, so the transition to IPv6 has
evolving Internet. The internet is growing rapidly and to be accompanied by the development of new
the number of available Internet addresses seemed to applications or the modification of existing ones, so
be insufficient to meet the future needs of the current that they can be used in IPv6 environments. It has
Internet. As a response, the Internet engineering task often been demonstrated that the difficulty of
force (IETF) introduced the Internet protocol version modifying existing applications varies significantly
6 (IPv6) as a substitute for the current Internet from one case to another. Depending upon the
protocol (IPv4)[20].We know that IPv6 has been applications at hand, it can be either a relatively
designed to remove all the defects and deficiencies of quick and easy process or a more complicated and
IPv4 [19].The transition between today’s IPv4 resource consuming task.
Internet and the future IPv6 based one will be a long
The remainder of the paper is organized as
process during which protocol versions will coexist.
follows. Section 2 presents types of Transition
Moving from IPv4 to IPv6 is not so easy, straight
2217

2. mechanisms. In Section 3 the Transition in IPv6, the IPv6 stack can coexist with upgraded IPv6
Transition scenarios in IPv6, Components of IPv6 applications on the same network system [20].
Transition plan .Finally the paper is concluded in
2.1.2 Tunnels
section 10.
The term “tunneling” refers to a means to
2. LITERATURE REVIEW
encapsulate one version of IP in another so the
Transition is a process by which the existing packets can be sent over a backbone that does not
services should work in the new environment but also support the encapsulated IP version. For example,
to continue to work with IPv4 nodes. The simplest when two isolated IPv6 networks need to
technique to introduce IPv6 without changing communicate over an IPv4 network, dual-stack
applications is to get benefits of dual stack, routers at the network edges can be used to set up a
supporting IPv4 and IPv6 simultaneously, tunnel which encapsulates the IPv6 packets within
maintaining old IPv4 applications and adding new IPv4, allowing the IPv6 systems to communicate
ones to communicate with IPv6 nodes. Many without having to upgrade the IPv4 network
methodologies have been studied to support infrastructure that exists between the networks [20].
transition to IPv6
2.1.3 Configured Tunnels
Depending on initial network architectures. The
The term “configured tunnels” is used when
simplest approach during initial transition is to use
network administrators manually configure the tunnel
IPv4 applications over the new IPv6 network
within the endpoint routers at each end of the tunnel.
environment. A pure IPv6 node will provide only the
Any changes to the network like renumbering must
IPv6 socket interface but old applications only work
be must manually reflected on the tunnel endpoint.
over IPv4 socket interface. Both interfaces are
Tunnels result in additional IP header overhead since
similar, but there are some incompatible differences
they encapsulate IPv6 packets within IPv4 (or vice
related with [19].
versa)[20].
1. DNS and IP-addresses management.
2. Communication constants and Data structures. 2.2 Automatic Tunnels
3. Functions names and Parameters[19]. The term “automatic tunnels” is used when a
device directly create their own tunnels to dual-
2.1 Types of Transition mechanisms stacked routers for shipping IP packets within IP. The
IPv6 Tunnel Broker (RFC 3053), 6to4 (RFC 3056),
Listed below is a description of the different Teredo (Tunneling IPv6 over UDP through NATs)
transition mechanisms options available to an agency and ISATAP (Intra-Site Automatic Tunnel
to ensure IPv4 and IPv6 interoperability. These Addressing Protocol) ship IPv6 packets within IPv4
mechanisms are categorized in the following three and can be referenced as IPv6-over-IPv4 mechanisms
broad classes: dual-stack, tunnels (includes while DSTM (Dual-stack Transition Mechanism)
configured and automatic tunnels), and translation ships IPv4 packets within IPv6 and can be reference
mechanisms[20]. as IPv4-over-IPv6 mechanism.
2.1.1 Dual-stacks The IPv6 tunnel broker mechanism uses
dual-stacked servers sitting between IPv6 and IPv4
The term “dual-stack” refers to TCP/IP networks to assist in the set up of a configured tunnel
capable devices providing support for both IPv4 and to a host. 6to4, Teredo and ISATAP allow end host
IPv6. It is important to understand that having a systems to create their own automatic tunnels to dual-
device being able to communicate over both IPv4 or stacked routers for shipping IPv6 packets within
IPv6 does not necessarily means that all applications IPv4. While ISATAP is mainly for IPv6-over-IPv4
operating within this device are capable of utilizing tunneling within a domain, all of the other IPv6-over-
both IPv4 and IPv6. The term “Dual-stack routing” IPv4 mechanisms are designed to tunnel IPv6 packets
refers to a network that is dual IP, that is to say all out of an IPv4-only administrative domain. Like
routers must be able to route both IPv4 and IPv6 [20]. configured tunnels, automatic tunneling has double
Requiring all new devices be both IPv4 and IP header overhead, since tunnels encapsulate IPv6
IPv6 capable permits these devices to have the ability packets within IPv4 (or vice versa).
to use either IP protocol version, depending on the DSTM technique provides a unique solution
services available, the network availability, service, to the IPv4-IPv6 transition problem. This mechanism
and the administrative policy. A transition scenario is designed to rapidly reduce the reliance on IPv4
which calls for “dual-stack everywhere” provides the routing and is intended for IPv6-only networks in
most flexible operational environment. Dual-stacked which hosts still occasionally need to exchange
hosts running on a dual-stack network allow information directly with other IPv4 hosts or
applications to migrate one at a time from IPv4 applications. Network administration is simplified
transport to IPv6 transport. Legacy applications and and the need of IPv4 global addresses is reduced.
devices that are not yet upgraded to support access to DSTM can be integrated with an IPv6 Tunnel Broker
for tighter security integration. DSTM routers can be
2218 2009 IEEE International Advance Computing Conference (IACC 2009)

3. coupled with IPv4 Firewalls and Intrusion Detection creates less work for the end user, making
systems to secure IPv4 tunnel endpoints from IPv4- renumbering of addresses easy and mobility is
based attacks [20]. possible. A better support for quality of service (QoS)
is provided in IPv6. Now fields in the IPv6 header
Special consideration must be given to the
define how traffic is handled and identified. Traffic
security risk associated with automatic tunneling as it
identification is performed by using a flow label field
allows user-nodes to establish tunnels that may
in the IPv6 header which allows routers to identify
bypass a site’s security checkpoints such as firewalls
and provide special handling for packets that belong
and intrusion detection systems. In general, a full
to a flow. There are many extensions to the IPv4
dual-stack along with IPv6-capable firewalls, guards,
protocol which provides security, such as IPSec and
intrusion detection, and end-host security may
HTTPs[9].
provide a more secure and interoperable IPv6
transition solution than tunneling. However, for 3.2 Transition Scenarios in IPv6
network infrastructures that contain IPv4-only or
Deploying IPv6 may seem a complex and
IPv6-only routing coupled with dual-stack end-nodes,
expensive operation however careful planning and
automatic tunneling provides a flexible transition
choosing the right techniques will actually make the
strategy. Again the risks associated with all potential
transition to IPv6 very smooth and easy. Deploying
solutions must be carefully considered[20].
involves three different components: The host
2.3. Protocols Translators operating system, the application and the network.
The most important requirement in IPv6 transition is
The term “translators” refers to devices
that existing services should work in the new
capable of translating traffic from IPv4 to IPv6 or
environment but also continue to work with IPv4
vice and versa. This mechanism is intended to
nodes. The simplest approach to introduce IPv6
eliminate the need for dual-stack network operation
without changing applications is to use dual-stack:
by translating traffic from IPv4-only devices to
supporting IPv4 and IPv6 simultaneously,
operate within an IPv6 infrastructure. This option is
maintaining old IPv4 applications and adding new
recommended only as a last resort because translation
ones to communicate with IPv6 nodes. This largely
interferes with objective of end-to-end transparency
increases the complexity of network administration
in network communications. Use of protocol
and maintains the address space scarce resource.
translators cause problems with NAT and highly
There is a pressure to start up new networks in the
constrain the use of IP-addressing[20].
new IPv6 environment without IPv4 support.
However, there is no a single global IPv6 network on
the same scale as the actual IPv4 and it will take
3. TRANSITION IN IPV6 some time to get it. Therefore, new applications
3.1 IPv6 should be designed to work in all environments:
single IPv4, single IPv6 or mixed environment
The entire purpose of IP is to provide connecting IPv6 with IPv4 nodes. That is, dual
unique global computer addressing to ensure that two protocol stack is necessary. However, it does not
computers communicating over the internet can mean supporting simultaneously IPv4 and IPv6
uniquely identify one another. Internet protocol routing. It is possible to use IPv6 applications on
version 6(IPv6) is the current version of Internet IPv4 network and IPv4 applications on IPv6 network.
Protocol and it is the successor of IPv4.IPv6 is a Therefore, there are many possible scenarios but only
network layer protocol for the Internet[1]. some of them will be used in practice [APPT]. To
The main features of IPv6 are larger select the best one it is necessary to know the initial
address space, address auto-configuration and host environment. Two possible environments can be
discovery ,better support for quality of service considered: the transition of working IPv4 network
,Network layer security ,mobility, routing, Porting and the setup of new network or service. For already
processing, and extensibility.IPv6 has a much larger working networks the better solution is to maintain
address space compared to IPv4 (addresses in IPv6 the IPv4 stack and introduce IPv6 stack in parallel
are 128 bits long versus 32 bits in IPv4).Which with the old one; that is to use the dual stack
allows greater flexibility in assigning addresses.IPv6 environment [DSTM]. It is the principal building
also supports for address auto-configuration and block during transitioning from IPv4 to IPv6. Dual
Router neighbor discovery. In IPv4 , hosts wait for stack mechanisms do not, by themselves, solve the
routers or neighboring nodes to advertise their IPv4 and IPv6 interworking problems, other
presence whereas an IPv6 host broadcasts a router important building block, addresses translation, is
solicitation message and waits for a response in the required many times. Translation refers to the direct
form of a router advertisement message. Auto- translation of protocols, including headers and
configuration allows an IPv6 node to obtain its own sometimes protocol payload. Protocol translation
IP address by using router solicitation to discover the often results in features loss. For instance, translation
network prefix from the local router and then of IPv6 header into an IPv4 header will lead to the
combining this prefix with its own embedded MAC loss of the IPv6 flow label. Translation can be
address to form its own IP address. This feature complemented with tunneling; which is used to
2009 IEEE International Advance Computing Conference (IACC 2009) 2219

4. bridge compatible networks across incompatible Step III: Applications are ready to work
ones. After transition period, IPv4 stack and IPv4 simultaneously on IPv4 and IPv6.
applications will be removed and result a pure IPv6
Step IV: IPv4 network has been removed.
environment. The organizations transition from IPv4
Communication with IPv4 nodes is only possible
to IPv6 follows more or less the same steps. Each
with the help of an IPv4 over IPv6 tunnel
step defines one transition scenario; see Figure 2. The
systems manager should provide applications to work End point: Finally all IPv4 networks and applications
in all of them. We can consider various scenarios in use IPv6
application porting process using dual-stack[20]:
The application porting process takes place
Start point: Applications have been designed between steps II and III. There are two probable
on IPv4 and the network is working with IPv4 only. scenarios during the transition. The first is based on
maintaining two application versions and the second
Step I: The network remains unchanged. Some IPv6
with only one dual version[20].
applications are available but IPv6 communication is
only possible through IPv6 over IPv4 tunnels.
Step II: IPv6 is available at network level unless
applications remain unchanged and only support
IPv4. Only IPv6 applications can use the IPv6
network.
3.3 Components of an IPv6 Transition Plan
Step I Step II Step3 Step4
App.IPv4 or IPv6 App.IPv4 or IPv6 App.IPv4
app. IPv4 or or IPv6
app.Ipv6 TCP/UDP
TCP/UDP TCP/UDP
TCP/UDP
IPv4 IPv6 IPv4 IPv6
IPv4 IPv6
IPv4 IPv6
Tunnel
IPv6
over
IPv4
N
Network routing IPv4. Network routing IPv4 Network routing IPv4 Network routing
or IPv6. or IPv6. IPv4 or IPv6.
programming to make it IP version agnostic. All
To deploy IPv6 transition involves three different types software programming used to store or display
components. network addresses must also be modified to support
the longer IPv6 addresses and their syntax. Support
1.Host Operating system, 2. Applications , for multicast also has to be added. There's no magic
3.Network. formula to make network software work with IPv6: it
3.3.1 Host Operating System(HOS) must be modified and tested for the new protocol[19].
Most of the modern operating systems now 4. TRANSITION TECHNIQUES
have two distinct IP stacks to support both IPv4 and
In this section, two different techniques for
IPv6 at the same time. The hosts configured this way
transition are discussed. These techniques are
are called dual stacked. Windows XP, Windows Server Transition to IPv6 without changing applications and
2003, Windows Vista, Linux, Mac OS X, FreeBSD,
Transition scenarios from the application point of
Solaris, AIX are all dual-stack capable operating
view[29].
systems in their recent versions[19].
The most important requirement in IPv6
transition is that existing services should work in the
3.3.2. Applications and Services
new environment but also continue to work with IPv4
nodes. The simplest approach to introduce IPv6
Networked applications and services must be
without changing applications is to use dual-stack:
modified, or ported, to support IPv6. Porting a piece of
supporting IPv4 and IPv6 simultaneously,
software usually involves modifying network maintaining old IPv4 applications and adding new
2220 2009 IEEE International Advance Computing Conference (IACC 2009)

5. ones to communicate with IPv6 nodes.This largely Step IV: IPv4 network has been removed.
increases the complexity of network administration and Communication with IPv4 nodes is only possible with
maintains the address space scarce resource.There is a the help of an
pressure to start up new networks in the new IPv6 IPv4 over IPv6 tunnel
environment without IPv4 support. However, there is
no a single global IPv6 network on the same scale as End point: Finally all IPv4 networks and applications
the actual IPv4 and it will take some time to get it. use IPv6.
Therefore, new applications should be designed to work The application porting process takes place between
in all environments: single IPv4, single IPv6 or mixed steps II and III. This paper is devoted to describe how
environment connecting IPv6 with IPv4 nodes. That is, to make such application adaptations. There are two
dual protocol stack is necessary. However, it does not probable scenarios during the transition. The first is
mean supporting simultaneously IPv4 and IPv6 routing. based on maintaining two application versions and
It is possible to use IPv6 applications on IPv4 network the second with only one dual version [20]
and IPv4 applications on IPv6 network. Therefore,
there are many possible scenarios but only some of 5. PROPOSAL
them will be used in practice[APPT]. To select the best
one it is necessary to know the initial environment. Two This Proposal is an enhancement of the
possible environments can be considered: the transition Transition to IPv6 without changing applications. The
of working IPv4 network and the setup of new network transition technology consists in developing a
or service. For already working networks the better complete set of applications designed to work only
solution is to maintain the IPv4 stack and introduce over IPv6 transport layer To finish IPv6 transition it
IPv6 stack in parallel with the old one; that is to use the is necessary only to removed IPv4 applications and
dual stack environment [DSTM]. It is the principal dual stack network. However the selection of
building block during transitioning from IPv4 to suitable application during IPv6 transition period it is
IPv6.Dual stack mechanisms do not, by themselves, a user responsibility. When tests configuration or
solve the IPv4 and IPv6 interworking problems other management of applications are considered ,the
important building block, addresses translation, is application selection is not a problem because user’s
required many times. Translation refers to the direct have technical knowledge [12].
translation of protocols, including headers and
sometimes protocol payload. Protocol translation often 6. CONCLUSION
results in features loss. For instance, translation of IPv6
header into an IPv4 header will lead to the loss of the This paper aims to analyze the challenges of
IPv6 flow label. Translation can be complemented with IPv6 transition issues. Different transition issues have
tunneling, which is used to bridge compatible networks been discussed. The two most popular transition
across incompatible ones. After transition period, IPv4 issues in IPv6 have been covered. Finally the an
stack and IPv4 applications will be removed and result enhancement of IPv6 transition has been proposed by
a pure IPv6 environment. The organizations transition applying the smooth porting process scenario during
from IPv4 to IPv6 follows more or less the same steps. IPv6 Transition (TIPv6) which supports Unless there
Each step defines one transition scenario; see Figure 2. are many proposed solutions to accelerate transition
The systems manager should provide applications to from IPv4 to IPv6, ultimately applications should be
work in all of them. We can consider various scenarios modified to protocol stacks configuration support all
in application porting process using dual-stack [20]: IPv4 and IPv6 communication types. Most existing
applications are written considering IPv4.In general
Start point: Applications have been designed on IPv4 most of them can be converted without too much
and the network is working with IPv4 only. effort. Many changes could be done automatically
and there are some scripts to do it. However there are
Step I: The network remains unchanged. Some IPv6 some applications which make special use of IPv4 or
applications are available but IPv6 communication is include advanced features , such as multicasting, raw
only sockets, or other IP options .Dual stack allows
possible through IPv6 over IPv4 tunnels. application to use both types of IP addresses like IPv6
and IPv4. Developers will only need to port their IPv4
Step II: IPv6 is available at network level unless applications to the new IPv6 API, considering that
applications remain unchanged and only support IPv4. applications could communicate using both protocol
Only versions ,depending on the destination code .Client
IPv6 applications can use the IPv6 network. applications should be prepared to connect to multi-
homed servers ,nodes that have more than one IP
Step III: Applications are ready to work simultaneously addresses. Hence a when a communication channel
on IPv4 and IPv6. to a multi-homed server list of IP addresses until they
find one that is working[28].
2009 IEEE International Advance Computing Conference (IACC 2009) 2221

6. 7. ACKNOWLEDGMENT [7].Jun-ichiro itojun Hagino, “ IPv6 Network Programming
” Elsevier digital press -2006.
This research paper has been supported by Department [8].Eva M. Castro, “Porting applications to IPv6 How To “
of studies in Computer Science,Manasagangothri,
University of Mysore, Department of Information [9].IPv6 network administration guide
Science & Engineering, R.L.Jalappa Institute of [10].Porting applications to IPv6, Pervasive technology labs
Technology and Department of Computer Science , at Indiana University.
Mangalagangothri , Mangalore University. I would like
[11].Porting an application to IPv6 : The quake 3 example.
to thanks our beloved supervisor Dr.Manjaiah.D.H for
providing his helpful discussion, support and [12].Yukwen Hsu, ” Porting an applications to IPv6 “ –
encouragement, to prepare this research paper on Microsoft corporation –Windows division.
“Smooth porting process scenario during IPv6 [13].Porting and performance aspects from IPv4 to IPv6:
Transition”. The case of open H323, International Journal of
communication Systems,6/04/2005.
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APIs
[1].RFC2553 – “ Basic Socket Interface Extensions for IPv6 ”
[15].Porting broadcast applications to IPv6 (Windows).
[2].Richard Stevens- “ Unix Network Programming ”,Volume
1 [16].Bahrouz Forouzan, “ TCP/IP Protocol suite “ – Tata
McGraw-Hill.
[3].Richard Stevens , Gary Wright, “ TCP/IP Illustrated
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[4].IETF IPv6 Transition Working Group,
http://www.6bone.net/ngtrans. [18].Networking IPv6 user guide for JDK/JRE 5.0
[5].S.Kent, R. Atkinson. “Security Architecture for the [19].Jean-Francois Tremblay, “ IPv6 Transition Strategies
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[20].Tomas P. de Miguel and Eva M. Castro,
[6].S.Tanenbaum, “ Computer Networks ”, Third Edition, “Programming guidelines on transition to IPv6 “
Prentice Hall Inc.,1996, pp. 686,413- 436,437-449.
2222 2009 IEEE International Advance Computing Conference (IACC 2009)