Indirect Routing of Mobile IP : A Non-Encapsulation Approach
International Journal of Computer Science and Network Security (2008)
Available from
Rafa Al-Qutaish's profile on Mendeley.
or
Abstract
Currently, when using the mobile IP indirect routing technique, it explicitly includes the encapsulation (such encapsulation is also called tunneling) approach. However, it is uncommon to use the non-encapsulation approach with the mobile IP indirect routing technique. In this paper, we propose a new approach in which we use the non-encapsulation approach to the indirect routing. In this way, the delay and the speed of CoA registration and communication processes within the indirect routing will be positively affected. Moreover, this way will decrease the delay and increase the speed of transmission.
Author-supplied keywords
Available from
Rafa Al-Qutaish's profile on Mendeley.
Page 1
Indirect Routing of Mobile IP : A Non-Encapsulation Approach
IJCSNS International Journal of Computer Science and Network Security, VOL.8 No.7, July 2008
124
Manuscript received July 5, 2008.
Manuscript revised July 20, 2008.
Indirect Routing of Mobile IP: A Non-Encapsulation Approach
Basil M. Al-Kasasbeh, Rafa E. Al-Qutaish and Khalid T. Al-Sarayreh
Faculty of Information Technology, Applied Science University, Amman 11931, Jordan
Summary
Currently, when using the mobile IP indirect routing technique, it
explicitly includes the encapsulation (such encapsulation is also
called tunneling) approach. However, it is uncommon to use the
non-encapsulation approach with the mobile IP indirect routing
technique. In this paper, we propose a new approach in which we
use the non-encapsulation approach to the indirect routing. In
this way, the delay and the speed of CoA registration and
communication processes within the indirect routing will be
positively affected. Moreover, this way will decrease the delay
and increase the speed of transmission.
Key words:
Mobile IP, Indirect Routing, Non-Encapsulation, Non-Tunneling,
registration, Address Mapping.
1. Introduction
Mobile IP is a standard protocol that builds on the Internet
Protocol by making mobility transparent to applications
and higher level protocols like TCP. Moreover, Mobile IP
works with a permanent IP address while moving around.
This address appears for routing purposes to be local to
the Home Agent router. As the Mobile Station moves,
there are no changes of routes in corporate routing tables.
Mobile IP can even work with Internet routing tables at a
global scale. All it takes is protocol support, a Home
Agent router, and one or more Foreign Agents to provide
mobile access [1].
Foreign Agent routers work with the Mobile IP host to
register new roaming locations with a Home Agent router.
Advertisements from the Foreign Agent notify the Mobile
Station of its presence as it roams.
The Mobile Station sends a Registration message to the
Home Agent via the new Foreign Agent, letting the Home
Agent know that message to it should be sent via a tunnel
to the Care-of Address (CoA) [2 and 3].
Packets headed from a "Correspondent node" towards the
mobile node get routed normally to the Home Agent
router. The Home Agent router encapsulates (such
encapsulation also called tunneling) these packets to the
Foreign Agent router near the Mobile Station. The Foreign
Agent router de-encapsulates the packets from the tunnel
and transmits them to the connected mobile node (visitor).
Return packets go from Mobile Station to Foreign Agent
and then directly to Correspondent node, unless "reverse
tunneling" is enabled. In order for all this to work, the
Mobile Node needs to have a special Mobile IP stack that
knows how to work with the Foreign Agent router, and
also how to send registration messages to the Home Agent
[4].
Basically, there is some MAC layer "cheating" on the
subnet between Foreign Agent and Mobile Station. For
outbound traffic, the Mobile Station dynamically sets the
Foreign Agent as default gateway, and forwards traffic to
it, even though they are not on the same subnet. For traffic
going towards the Mobile Station, the Foreign Agent uses
a host route and a local ARP entry to get traffic to the
Mobile Station, even though its address may not be that of
the local subnet [1], see Figure 1.
As commonly known, the encapsulation process itself will
increase the transmission delay, and the process of
encapsulation of the sending packet will enlarge its size,
and then the speed of communication process will be
decreased based on the enlarged size of the new packet
sent from the home agent. In addition, the de-
encapsulation process will need a time to return the new
packet to its original structure in which this process will
also increase the delay of the communication process.
In this paper, we propose a new approach in which we use
the non-encapsulation approach to the indirect routing. In
this way, the delay and the speed of transmission of the
CoA registration and communication processes within the
indirect routing will be positively affected. Moreover, this
way will decrease the delay and increase the speed.
The rest of this paper is organized as follows: Section 2
gives a general overview about the indirect routing
technique for Mobile IP. In section 3, we describe the
details of the proposed approach. Section 4 illustrates an
example of the proposed approach, and finally, section 5
concludes the paper.
124
Manuscript received July 5, 2008.
Manuscript revised July 20, 2008.
Indirect Routing of Mobile IP: A Non-Encapsulation Approach
Basil M. Al-Kasasbeh, Rafa E. Al-Qutaish and Khalid T. Al-Sarayreh
Faculty of Information Technology, Applied Science University, Amman 11931, Jordan
Summary
Currently, when using the mobile IP indirect routing technique, it
explicitly includes the encapsulation (such encapsulation is also
called tunneling) approach. However, it is uncommon to use the
non-encapsulation approach with the mobile IP indirect routing
technique. In this paper, we propose a new approach in which we
use the non-encapsulation approach to the indirect routing. In
this way, the delay and the speed of CoA registration and
communication processes within the indirect routing will be
positively affected. Moreover, this way will decrease the delay
and increase the speed of transmission.
Key words:
Mobile IP, Indirect Routing, Non-Encapsulation, Non-Tunneling,
registration, Address Mapping.
1. Introduction
Mobile IP is a standard protocol that builds on the Internet
Protocol by making mobility transparent to applications
and higher level protocols like TCP. Moreover, Mobile IP
works with a permanent IP address while moving around.
This address appears for routing purposes to be local to
the Home Agent router. As the Mobile Station moves,
there are no changes of routes in corporate routing tables.
Mobile IP can even work with Internet routing tables at a
global scale. All it takes is protocol support, a Home
Agent router, and one or more Foreign Agents to provide
mobile access [1].
Foreign Agent routers work with the Mobile IP host to
register new roaming locations with a Home Agent router.
Advertisements from the Foreign Agent notify the Mobile
Station of its presence as it roams.
The Mobile Station sends a Registration message to the
Home Agent via the new Foreign Agent, letting the Home
Agent know that message to it should be sent via a tunnel
to the Care-of Address (CoA) [2 and 3].
Packets headed from a "Correspondent node" towards the
mobile node get routed normally to the Home Agent
router. The Home Agent router encapsulates (such
encapsulation also called tunneling) these packets to the
Foreign Agent router near the Mobile Station. The Foreign
Agent router de-encapsulates the packets from the tunnel
and transmits them to the connected mobile node (visitor).
Return packets go from Mobile Station to Foreign Agent
and then directly to Correspondent node, unless "reverse
tunneling" is enabled. In order for all this to work, the
Mobile Node needs to have a special Mobile IP stack that
knows how to work with the Foreign Agent router, and
also how to send registration messages to the Home Agent
[4].
Basically, there is some MAC layer "cheating" on the
subnet between Foreign Agent and Mobile Station. For
outbound traffic, the Mobile Station dynamically sets the
Foreign Agent as default gateway, and forwards traffic to
it, even though they are not on the same subnet. For traffic
going towards the Mobile Station, the Foreign Agent uses
a host route and a local ARP entry to get traffic to the
Mobile Station, even though its address may not be that of
the local subnet [1], see Figure 1.
As commonly known, the encapsulation process itself will
increase the transmission delay, and the process of
encapsulation of the sending packet will enlarge its size,
and then the speed of communication process will be
decreased based on the enlarged size of the new packet
sent from the home agent. In addition, the de-
encapsulation process will need a time to return the new
packet to its original structure in which this process will
also increase the delay of the communication process.
In this paper, we propose a new approach in which we use
the non-encapsulation approach to the indirect routing. In
this way, the delay and the speed of transmission of the
CoA registration and communication processes within the
indirect routing will be positively affected. Moreover, this
way will decrease the delay and increase the speed.
The rest of this paper is organized as follows: Section 2
gives a general overview about the indirect routing
technique for Mobile IP. In section 3, we describe the
details of the proposed approach. Section 4 illustrates an
example of the proposed approach, and finally, section 5
concludes the paper.
Page 2
IJCSNS International Journal of Computer Science and Network Security, VOL.8 No.7, July 2008
125
Fig. 1 Indirect Routing Scenario
2. Indirect Routing: General Overview
2.1 How Mobile IP Works using Indirect Routing
Approach
IP routes packets from a source endpoint to a destination
by allowing routers to forward packets from incoming
network interfaces to outbound interfaces according to
routing tables. The routing tables typically maintain the
next-hop information for each destination IP address,
according to the number of networks to which that IP
address is connected. The network number is derived from
the IP address by masking off some of the low-order bits.
Thus, the IP address typically carries with it information
that specifies the IP node's point of attachment. In Mobile
IP the home agent redirects packets from the Home
Network to the Care-of Address by constructing a new IP
header that contains the Mobile Station’s Care-of Address
as the destination IP address. This new header then
encapsulates the original packet, causing the Mobile
Station’s home address to have no effect on the
encapsulated packet's routing until it arrives at the Care-of
Address. Such encapsulation suggests that the packet
burrows through the Internet, bypassing the usual effects
of IP routing.
Mobile IP, then, is best understood as the cooperation of
three separable mechanisms [1 and 3]:
• Discovering the Care-of Address (CoA),
• Registering the Care-of Address (CoA), and
• Tunneling to the Care-of Address (CoA).
2.2 Discovering the Care-of Address
The Mobile IP discovery process has been built on top of
an existing standard protocol, Router Advertisement,
specified in [6]. Mobile IP discovery does not modify the
original fields of existing router advertisements but simply
extends them to associate mobility functions. Thus, a
router advertisement can carry information about default
routers, just as before, and in addition carry further
information about one or more Care-of Addresses. When
the router advertisements are extended to also contain the
needed Care-of Address, they are known as agent
advertisements. Home agents and foreign agents typically
broadcast agent advertisements at regular intervals. If a
125
Fig. 1 Indirect Routing Scenario
2. Indirect Routing: General Overview
2.1 How Mobile IP Works using Indirect Routing
Approach
IP routes packets from a source endpoint to a destination
by allowing routers to forward packets from incoming
network interfaces to outbound interfaces according to
routing tables. The routing tables typically maintain the
next-hop information for each destination IP address,
according to the number of networks to which that IP
address is connected. The network number is derived from
the IP address by masking off some of the low-order bits.
Thus, the IP address typically carries with it information
that specifies the IP node's point of attachment. In Mobile
IP the home agent redirects packets from the Home
Network to the Care-of Address by constructing a new IP
header that contains the Mobile Station’s Care-of Address
as the destination IP address. This new header then
encapsulates the original packet, causing the Mobile
Station’s home address to have no effect on the
encapsulated packet's routing until it arrives at the Care-of
Address. Such encapsulation suggests that the packet
burrows through the Internet, bypassing the usual effects
of IP routing.
Mobile IP, then, is best understood as the cooperation of
three separable mechanisms [1 and 3]:
• Discovering the Care-of Address (CoA),
• Registering the Care-of Address (CoA), and
• Tunneling to the Care-of Address (CoA).
2.2 Discovering the Care-of Address
The Mobile IP discovery process has been built on top of
an existing standard protocol, Router Advertisement,
specified in [6]. Mobile IP discovery does not modify the
original fields of existing router advertisements but simply
extends them to associate mobility functions. Thus, a
router advertisement can carry information about default
routers, just as before, and in addition carry further
information about one or more Care-of Addresses. When
the router advertisements are extended to also contain the
needed Care-of Address, they are known as agent
advertisements. Home agents and foreign agents typically
broadcast agent advertisements at regular intervals. If a
Page 3
IJCSNS International Journal of Computer Science and Network Security, VOL.8 No.7, July 2008
126
Mobile Station needs to get a Care-of Address and does
not wish to wait for the periodic advertisement, the Mobile
Station can broadcast a request which will be answered by
any foreign agent or home agent that receives it. Home
agents use agent advertisements to make themselves
known, even if they do not offer any Care-of Addresses.
However, it is not possible to associate preferences to the
various Care-of Addresses in the router advertisement, as
is the case with default routers.
The IETF working group was concerned that dynamic
preference values might destabilize the operation of
Mobile IP. Because no one could defend static preference
assignments except for backup mobility agents, which do
not help distribute the routing load, the group eventually
decided not to use the preference assignments with the
Care-of Address list.
Thus, an agent advertisement performs the following
functions [6]:
• allows for the detection of mobility agents,
• lists one or more available Care-of Addresses,
• informs the mobile node about special features
provided by foreign agents, for example, alternative
encapsulation techniques,
• lets mobile nodes determine the network number and
status of their link to the Internet, and
• lets the mobile node know whether the agent is a home
agent, a foreign agent, or both, and therefore whether it
is on its home network or a foreign network.
Mobile Station use router solicitations as defined in [6] to
detect any change in the set of mobility agents available at
the current point of attachment. If advertisements are no
longer detectable from a Foreign Agent that previously
had offered a Care-of Address to the Mobile Station, the
Mobile Station should assume that Foreign Agent is no
longer within range of the Mobile Station’s network
interface. In this situation, the Mobile Station should begin
to hunt for a new Care-of Address, or possibly use a Care-
of Address known from advertisements it is still receiving.
The Mobile Station may choose to wait for another
advertisement if it has not received any recently advertised
Care-of Addresses, or it may send an agent request [1].
2.3 Registering the Care-of Address
Once a Mobile Station has a Care-of Address, its home
agent must find out about it. The registration process has
already been defined by Mobile IP for this purpose. The
process begins when the Mobile Station, possibly with the
assistance of a Foreign Agent, sends a registration request
with the Care-of Address information. When the Home
Agent receives this request, it adds the necessary
information to its routing table, approves the request, and
sends a registration reply back to the Mobile Station [7].
2.4 Tunneling to the Care-of Address
The default encapsulation mechanism that must be
supported by all mobility agents using Mobile IP is IP-
within-IP. Using IP-within-IP, the home agent, the tunnel
source, inserts a new IP header, or tunnel header, in front
of the IP header of any datagram addressed to the mobile
node's home address. The new tunnel header uses the
mobile node's Care-of Address as the destination IP
address, or tunnel destination. The tunnel source IP
address is the home agent, and the tunnel header uses 4 as
the higher level protocol number, indicating that the next
protocol header is again an IP header. In IP-within-IP the
entire original IP header is preserved as the first part of the
payload of the tunnel header. Therefore, to recover the
original packet, the foreign agent only has to eliminate the
tunnel header and deliver the rest to the mobile node [5].
3. The Proposed Approach
The proposed approach will use the non-encapsulation
technique with the indirect routing of Mobile IP.
In this section, we will discuss the CoA registration
process (see Figure 2) and the related packet delivery
mechanism (see Figure 3).
3.1 The Proposed CoA Registration Process
Using the proposed approach, when the Mobile Station
moves from its own network (Home Network) to another
network (Foreign Network), Mobile Station receives an
ICMP advertisement message (with mobility agent
advertisement extension) that contains a Core-of Address
(CoA) and new field which called flags (instead of old
RBHFMGrT).
The new proposed Flags field contains the following bits
R0HF0000, and this means that there is no encapsulation
format since R bit used for registration (if it is required), H
stands for home bit, F for foreign bit, and other bits set to
zeros, see Table 1.
126
Mobile Station needs to get a Care-of Address and does
not wish to wait for the periodic advertisement, the Mobile
Station can broadcast a request which will be answered by
any foreign agent or home agent that receives it. Home
agents use agent advertisements to make themselves
known, even if they do not offer any Care-of Addresses.
However, it is not possible to associate preferences to the
various Care-of Addresses in the router advertisement, as
is the case with default routers.
The IETF working group was concerned that dynamic
preference values might destabilize the operation of
Mobile IP. Because no one could defend static preference
assignments except for backup mobility agents, which do
not help distribute the routing load, the group eventually
decided not to use the preference assignments with the
Care-of Address list.
Thus, an agent advertisement performs the following
functions [6]:
• allows for the detection of mobility agents,
• lists one or more available Care-of Addresses,
• informs the mobile node about special features
provided by foreign agents, for example, alternative
encapsulation techniques,
• lets mobile nodes determine the network number and
status of their link to the Internet, and
• lets the mobile node know whether the agent is a home
agent, a foreign agent, or both, and therefore whether it
is on its home network or a foreign network.
Mobile Station use router solicitations as defined in [6] to
detect any change in the set of mobility agents available at
the current point of attachment. If advertisements are no
longer detectable from a Foreign Agent that previously
had offered a Care-of Address to the Mobile Station, the
Mobile Station should assume that Foreign Agent is no
longer within range of the Mobile Station’s network
interface. In this situation, the Mobile Station should begin
to hunt for a new Care-of Address, or possibly use a Care-
of Address known from advertisements it is still receiving.
The Mobile Station may choose to wait for another
advertisement if it has not received any recently advertised
Care-of Addresses, or it may send an agent request [1].
2.3 Registering the Care-of Address
Once a Mobile Station has a Care-of Address, its home
agent must find out about it. The registration process has
already been defined by Mobile IP for this purpose. The
process begins when the Mobile Station, possibly with the
assistance of a Foreign Agent, sends a registration request
with the Care-of Address information. When the Home
Agent receives this request, it adds the necessary
information to its routing table, approves the request, and
sends a registration reply back to the Mobile Station [7].
2.4 Tunneling to the Care-of Address
The default encapsulation mechanism that must be
supported by all mobility agents using Mobile IP is IP-
within-IP. Using IP-within-IP, the home agent, the tunnel
source, inserts a new IP header, or tunnel header, in front
of the IP header of any datagram addressed to the mobile
node's home address. The new tunnel header uses the
mobile node's Care-of Address as the destination IP
address, or tunnel destination. The tunnel source IP
address is the home agent, and the tunnel header uses 4 as
the higher level protocol number, indicating that the next
protocol header is again an IP header. In IP-within-IP the
entire original IP header is preserved as the first part of the
payload of the tunnel header. Therefore, to recover the
original packet, the foreign agent only has to eliminate the
tunnel header and deliver the rest to the mobile node [5].
3. The Proposed Approach
The proposed approach will use the non-encapsulation
technique with the indirect routing of Mobile IP.
In this section, we will discuss the CoA registration
process (see Figure 2) and the related packet delivery
mechanism (see Figure 3).
3.1 The Proposed CoA Registration Process
Using the proposed approach, when the Mobile Station
moves from its own network (Home Network) to another
network (Foreign Network), Mobile Station receives an
ICMP advertisement message (with mobility agent
advertisement extension) that contains a Core-of Address
(CoA) and new field which called flags (instead of old
RBHFMGrT).
The new proposed Flags field contains the following bits
R0HF0000, and this means that there is no encapsulation
format since R bit used for registration (if it is required), H
stands for home bit, F for foreign bit, and other bits set to
zeros, see Table 1.
Page 4
IJCSNS International Journal of Computer Science and Network Security, VOL.8 No.7, July 2008
127
CoA: 200.5.3.15
HA: 195.10.3.10
MA: 195.10.3.5
TTL: 9999
ID: 520
.
.
.
Registration Request
MS FA HA
HA: 195.10.3.10
CoA: 200.5.3.15
MA: 195.10.3.5
TTL: 5000
ID: 520
.
.
.
Registration Response
ICM
P A
dve
rtis
em
ent
CoA: 200.5.3.15
HA: 195.10.3.10
MA: 195.10.3.5
TTL: 9999
ID: 520
.
.
.
Registration Request
HA: 195.10.3.10
CoA: 200.5.3.15
MA: 195.10.3.5
TTL: 5000
ID: 520
.
.
.
Registration Response
Ti
m
e
Type= 9 Code= 0 Check Sum
Router Address
Type= 16 Length Sequence Number
TTL Flags Reserved
Zero or more Care-of-Addresses (CoA)
. . .
Standard ICMP
Fields
Mobility Agent
Advertisement
Extension
Fig. 2 The Non-Encapsulation Registration Process
Mobile station after receiving its new address (CoA) must
register CoA in its home agent. It sends a registration
request message to the foreign agent, foreign agent binds
mobile permanent address to the new CoA which already
127
CoA: 200.5.3.15
HA: 195.10.3.10
MA: 195.10.3.5
TTL: 9999
ID: 520
.
.
.
Registration Request
MS FA HA
HA: 195.10.3.10
CoA: 200.5.3.15
MA: 195.10.3.5
TTL: 5000
ID: 520
.
.
.
Registration Response
ICM
P A
dve
rtis
em
ent
CoA: 200.5.3.15
HA: 195.10.3.10
MA: 195.10.3.5
TTL: 9999
ID: 520
.
.
.
Registration Request
HA: 195.10.3.10
CoA: 200.5.3.15
MA: 195.10.3.5
TTL: 5000
ID: 520
.
.
.
Registration Response
Ti
m
e
Type= 9 Code= 0 Check Sum
Router Address
Type= 16 Length Sequence Number
TTL Flags Reserved
Zero or more Care-of-Addresses (CoA)
. . .
Standard ICMP
Fields
Mobility Agent
Advertisement
Extension
Fig. 2 The Non-Encapsulation Registration Process
Mobile station after receiving its new address (CoA) must
register CoA in its home agent. It sends a registration
request message to the foreign agent, foreign agent binds
mobile permanent address to the new CoA which already
Page 5
IJCSNS International Journal of Computer Science and Network Security, VOL.8 No.7, July 2008
128
given to mobile station in its own table. Then foreign
agent forwards a registration request message to the home
agent which has the original mobile station. The home
agent receives a registration request message, then updates
its own addressing table by binding the CoA to MA of a
particular mobile station. The home agent sends a
registration response message to the foreign agent, and
then the foreign agent forwards a registration response
message to the mobile station.
In this registration process, we can note that the
encapsulation format is ignored in all steps. This approach
will save the time of registration process and decrease the
processing delay in all parties of the registration process.
Figure 2 illustrates the non-encapsulation registration
process. Also, Table 1 describes the proposed and old
flags fields of the ICMP advertisement message.
3.2 The Related Packet Delivery Mechanism
To explain this packet delivery mechanism, we have to
discuss two potential scenarios. The first scenario is when
the mobile station (MS) is currently located within the
home network (HN). In this way, the correspondent node
(CN) directly sends a packet to the home agent (HA) using
the traditional internet routing mechanisms, taking into
consideration that the destination IP address of the sent
packet is the mobile permanent address (MA). Since the
mobile is already located within the home agent scope,
then it will directly forward the packet to the intended
mobile station. The mobile station receives the packet and
reply a confirmation response if it is required.
The second scenario is when the mobile station is
currently located at a foreign network (outside the home
network). In this scenario, the correspondent node sends a
packet to the home agent where the destination IP address
of the sent packet is a mobile permanent address (MA).
The home agent receives the packet and checks its
addressing table to identify the current temporary IP
address (CoA) of the mobile station. Furthermore, the
home agent perform a header processing by coping all
fields along with the data as it is except the destination IP
address filed which must be change to be the CoA instead
of MA, see Figure 3.
The home agent forwards the processed packet to the
foreign agent. When the foreign agent received the packet,
it will forward it directly to the mobile station since no
need to any further header translation. The mobile station
receives the packet which has the CoA as its destination
address, and it will recognize that this packet is sent to its
attention. If it is required, the mobile station will send a
reply message to the CN, we should note that the source IP
address of the reply message is MA and the destination IP
address is CN, see Figure 3.
Figure 4 presents a flowchart of the two potential
scenarios of the packet delivery mechanism which is
discussed within this section.
Fig. 3 Non-Encapsulation Communication Process
128
given to mobile station in its own table. Then foreign
agent forwards a registration request message to the home
agent which has the original mobile station. The home
agent receives a registration request message, then updates
its own addressing table by binding the CoA to MA of a
particular mobile station. The home agent sends a
registration response message to the foreign agent, and
then the foreign agent forwards a registration response
message to the mobile station.
In this registration process, we can note that the
encapsulation format is ignored in all steps. This approach
will save the time of registration process and decrease the
processing delay in all parties of the registration process.
Figure 2 illustrates the non-encapsulation registration
process. Also, Table 1 describes the proposed and old
flags fields of the ICMP advertisement message.
3.2 The Related Packet Delivery Mechanism
To explain this packet delivery mechanism, we have to
discuss two potential scenarios. The first scenario is when
the mobile station (MS) is currently located within the
home network (HN). In this way, the correspondent node
(CN) directly sends a packet to the home agent (HA) using
the traditional internet routing mechanisms, taking into
consideration that the destination IP address of the sent
packet is the mobile permanent address (MA). Since the
mobile is already located within the home agent scope,
then it will directly forward the packet to the intended
mobile station. The mobile station receives the packet and
reply a confirmation response if it is required.
The second scenario is when the mobile station is
currently located at a foreign network (outside the home
network). In this scenario, the correspondent node sends a
packet to the home agent where the destination IP address
of the sent packet is a mobile permanent address (MA).
The home agent receives the packet and checks its
addressing table to identify the current temporary IP
address (CoA) of the mobile station. Furthermore, the
home agent perform a header processing by coping all
fields along with the data as it is except the destination IP
address filed which must be change to be the CoA instead
of MA, see Figure 3.
The home agent forwards the processed packet to the
foreign agent. When the foreign agent received the packet,
it will forward it directly to the mobile station since no
need to any further header translation. The mobile station
receives the packet which has the CoA as its destination
address, and it will recognize that this packet is sent to its
attention. If it is required, the mobile station will send a
reply message to the CN, we should note that the source IP
address of the reply message is MA and the destination IP
address is CN, see Figure 3.
Figure 4 presents a flowchart of the two potential
scenarios of the packet delivery mechanism which is
discussed within this section.
Fig. 3 Non-Encapsulation Communication Process
Page 6
IJCSNS International Journal of Computer Science and Network Security, VOL.8 No.7, July 2008
129
Table 1: Description of the Proposed and Old Flags Field
The Proposed Flags Field
Agent Flags (R0HF0000)
Home Agent 00100000
Foreign Agent 10010000
R: Registration is required
H: Home Agent
F: Foreign Agent
The Old Flags Field (RBHFMGrT)
R: Registration Bit
H: Home Bit
F: Foreign Bit
MG: Encapsulation Format
Fig. 4 The Packet Delivery Mechanism
129
Table 1: Description of the Proposed and Old Flags Field
The Proposed Flags Field
Agent Flags (R0HF0000)
Home Agent 00100000
Foreign Agent 10010000
R: Registration is required
H: Home Agent
F: Foreign Agent
The Old Flags Field (RBHFMGrT)
R: Registration Bit
H: Home Bit
F: Foreign Bit
MG: Encapsulation Format
Fig. 4 The Packet Delivery Mechanism
Page 8
IJCSNS International Journal of Computer Science and Network Security, VOL.8 No.7, July 2008
131
5. Conclusion
Presently, the encapsulation (or what is also called
tunneling) of the packets is the common approach of the
Mobile IP indirect routing. By other hand, it is uncommon
to use the non-encapsulation approach with the mobile IP
indirect routing technique.
As well known, the encapsulation process itself will
increase the transmission delay, and the process of
encapsulation of the sending packet will enlarge its size,
and then the speed of communication process will be
decreased based on the enlarged size of the new packet
sent from the home agent. In addition, the de-
encapsulation process will need a time to return the new
packet to its original structure in which this process will
also increase the delay of the communication process.
In this paper, we proposed a new approach in which we
used the non-encapsulation technique in the indirect
routing. Consequently, the delay and the speed of
transmission of the CoA registration and communication
processes within the indirect routing will be positively
affected. Moreover, this way will decrease the delay and
increase the speed. Furthermore, there is no any kind of
size enlargement of the sent packets.
Acknowledgments
This work was supported by the Applied Science
University, Amman, Jordan.
References
[1] C. E. Perkins, “Mobile Networking Through Mobile IP”,
IEEE Internet Computing Journal, Vol. 2, No. 1, 1998, pp.
58-69.
[2] J. Kurose, K. Ross, Computer Networking: A Top-Down
Approach Featuring the Internet, 4th edition. Pearson
Education, Addison-Wesley, Boston, MA, USA, 2008.
[3] C. E. Perkins, “IP Mobility Support for IPV4”, RFC Editor,
REC3344, USA Online: http://portal.acm.org/citation.
cfm?id=RFC3344#, 2002.
[4] C. E. Perkins, “Mobile IP: Design Principles and Practice”,
Addison-Wesley, Reading, MA, USA, 1998.
[5] C. E. Perkins, “IP Encapsulation within IP”, Internet RFC,
REC2003, USA, Online: http://portal.acm.org/citation.
cfm?id=RFC2003, 1996.
[6] S. Deering, “ICMP Router Discovery Messages”, RFC
Editor, REC1256, USA, Online: http://portal.acm.org
/citation.cfm?id=RFC1256, 1991.
[7] H. Haverinen, A. Kuikka and T. Maattanen, “A portable
mobile IP implementation”, in Proceedings of 25th Annual
IEEE Conference on Local Computer Networks –
(LCN’2000), Tampa, Florida, USA, November, 8-10, 2000.
Dr. Basil M. Al-Kasasbeh (1971)
received the M.S. and PhD
degrees in Networks, Systems and
Communication Devices from Siberian
State University of Telecommunications
and Informatics, Novosibirsk in 1994 and
2002, respectively. During 2002-2003, he
was an Assistant Professor at the Faculty
of Information Technology, University of
Jordan. Since 2003, he is an Assistant
Professor at the Faculty of Information technology, Applied
Science University in Jordan. His research interests include:
Mobile and Wireless Systems, Mobile IP, and IPV6.
Dr. Rafa E. Al-Qutaish (1970)
received the B.S. degree in
Computer Science from Yarmouk
University, Jordan in 1993, the MSc
degree in Software Engineering from
University of Putra, Malaysia in 1998, and
PhD degree in Software Engineering from
the School of Higher Technology,
University of Quebec, Canada in 2007.
Since 2007, he is an Assistant Professor at
the Faculty of Information Technology, Applied Science
University. His research interests include: Communication
Software Engineering, Software Measurements, Software
Engineering Standardizations, Software Quality Engineering,
and Applied Artificial Intelligence. He is a senior member of
IEEE-CS and acting member of ACM.
Dr. Khalid T. Al-Sarayreh (1971)
received the B.S. degree in
Computer Science from Mu’tah University,
Jordan in 1993, the MSc in Computer
Engineering from Yarmouk University,
Jordan in 2003, and PhD in Computer
Information Systems from the Arab
Academy for Financial and Banking
Sciences, Jordan in 2005. During 2002-
2005, he stayed in the KADDB, Ministry
of Defense. From 2005 to 2006, he was an Assistant Professor at
the Jordan University. Since 2006, He is as an Assistant
Professor at the Faculty of Information Technology, Applied
Science University/ His research interests include: Software
Real-Time Embedded Systems, Computer Networks, and
Applied Artificial Intelligence
131
5. Conclusion
Presently, the encapsulation (or what is also called
tunneling) of the packets is the common approach of the
Mobile IP indirect routing. By other hand, it is uncommon
to use the non-encapsulation approach with the mobile IP
indirect routing technique.
As well known, the encapsulation process itself will
increase the transmission delay, and the process of
encapsulation of the sending packet will enlarge its size,
and then the speed of communication process will be
decreased based on the enlarged size of the new packet
sent from the home agent. In addition, the de-
encapsulation process will need a time to return the new
packet to its original structure in which this process will
also increase the delay of the communication process.
In this paper, we proposed a new approach in which we
used the non-encapsulation technique in the indirect
routing. Consequently, the delay and the speed of
transmission of the CoA registration and communication
processes within the indirect routing will be positively
affected. Moreover, this way will decrease the delay and
increase the speed. Furthermore, there is no any kind of
size enlargement of the sent packets.
Acknowledgments
This work was supported by the Applied Science
University, Amman, Jordan.
References
[1] C. E. Perkins, “Mobile Networking Through Mobile IP”,
IEEE Internet Computing Journal, Vol. 2, No. 1, 1998, pp.
58-69.
[2] J. Kurose, K. Ross, Computer Networking: A Top-Down
Approach Featuring the Internet, 4th edition. Pearson
Education, Addison-Wesley, Boston, MA, USA, 2008.
[3] C. E. Perkins, “IP Mobility Support for IPV4”, RFC Editor,
REC3344, USA Online: http://portal.acm.org/citation.
cfm?id=RFC3344#, 2002.
[4] C. E. Perkins, “Mobile IP: Design Principles and Practice”,
Addison-Wesley, Reading, MA, USA, 1998.
[5] C. E. Perkins, “IP Encapsulation within IP”, Internet RFC,
REC2003, USA, Online: http://portal.acm.org/citation.
cfm?id=RFC2003, 1996.
[6] S. Deering, “ICMP Router Discovery Messages”, RFC
Editor, REC1256, USA, Online: http://portal.acm.org
/citation.cfm?id=RFC1256, 1991.
[7] H. Haverinen, A. Kuikka and T. Maattanen, “A portable
mobile IP implementation”, in Proceedings of 25th Annual
IEEE Conference on Local Computer Networks –
(LCN’2000), Tampa, Florida, USA, November, 8-10, 2000.
Dr. Basil M. Al-Kasasbeh (1971)
received the M.S. and PhD
degrees in Networks, Systems and
Communication Devices from Siberian
State University of Telecommunications
and Informatics, Novosibirsk in 1994 and
2002, respectively. During 2002-2003, he
was an Assistant Professor at the Faculty
of Information Technology, University of
Jordan. Since 2003, he is an Assistant
Professor at the Faculty of Information technology, Applied
Science University in Jordan. His research interests include:
Mobile and Wireless Systems, Mobile IP, and IPV6.
Dr. Rafa E. Al-Qutaish (1970)
received the B.S. degree in
Computer Science from Yarmouk
University, Jordan in 1993, the MSc
degree in Software Engineering from
University of Putra, Malaysia in 1998, and
PhD degree in Software Engineering from
the School of Higher Technology,
University of Quebec, Canada in 2007.
Since 2007, he is an Assistant Professor at
the Faculty of Information Technology, Applied Science
University. His research interests include: Communication
Software Engineering, Software Measurements, Software
Engineering Standardizations, Software Quality Engineering,
and Applied Artificial Intelligence. He is a senior member of
IEEE-CS and acting member of ACM.
Dr. Khalid T. Al-Sarayreh (1971)
received the B.S. degree in
Computer Science from Mu’tah University,
Jordan in 1993, the MSc in Computer
Engineering from Yarmouk University,
Jordan in 2003, and PhD in Computer
Information Systems from the Arab
Academy for Financial and Banking
Sciences, Jordan in 2005. During 2002-
2005, he stayed in the KADDB, Ministry
of Defense. From 2005 to 2006, he was an Assistant Professor at
the Jordan University. Since 2006, He is as an Assistant
Professor at the Faculty of Information Technology, Applied
Science University/ His research interests include: Software
Real-Time Embedded Systems, Computer Networks, and
Applied Artificial Intelligence
Sign up today - FREE
Mendeley saves you time finding and organizing research. Learn more
- All your research in one place
- Add and import papers easily
- Access it anywhere, anytime
Start using Mendeley in seconds!
Readership Statistics
1 Reader on Mendeley
by Discipline
by Academic Status
100% Assistant Professor
by Country
100% United Arab Emirates