Transcript Cellular IP

Cellular IP
Myungchul Kim
[email protected]
–
–
–
–
seamless mobility support
picocellular environment
address translation in Mobile IP
Mobile IP is not appropriate for seamless mobility: registration
between MN and HA
– paging, passive connectivity -> scalability
– Mobile IP does not support the notion of seamless mobility,
passive connectivity, or paging
• Related Work
– Mobile IP is extended by arranging FAs in a hierarchy [6, 8]
– Cellular IP
• employ per-mobile-host states
• hop-by-hop routing to achieve fast handoff control
• passive connectivity: reduce the search time and increase
protocol scalability
• a layer three routing protocol
– Hawaii [5]: Hawaii nodes are IP routers
• the use of explicit signaling messages is limited in Cellular IP
– minimizing service disruption during handoff
– Cellular IP handoff aims at simplicity, eliminating the reliance on
multicast and minimizing explicit signaling
• Protocol Overview
– The Network Model
• For base station, IP routing is replaced by Cellular IP routing
and location management.
• without tunneling or address conversion
• to minimize control messages, regular data packets
transmitted by mobile hosts are used to refresh host location
information: uplink and downlink
– Routing
• each base station maintains a routing cache
• mapping (X, BS3) at BS2 in Figure
• route-time-out, route-update packet and route-update time.
– Handoff: hard handoff and semisoft handoff
– Hard Handoff
• handoff latency: the round-trip time between the mobile host
and the crossover base station
• only a local node has to be notified rather than a possibly
distant HA in the case of Mobile IP
• way to reduce packet loss: interaction between the old and new
base stations during handoff
– Semisoft handoff
• the routing cache mapping associated with the new base station
must be created before the actual handoff takes place.
• a constant delay along the new path between the crossover and
new base stations
– Paging
• paging-update, paging-update-time, paging-cache, pagingtimeout
– Security
• impersonation and snooping attacks
• only control packets are authenticated
• Evaluation
– Testbed
• FreeBSD 2.2.6, Windows and Linux
• Berkeley Packet Filter’s Packet Capture Library (PCAP)
• WaveLAN I, II
• a utility tool for manual handoff
– Handoff
• ttcp: TCP performance
• UDP Performance
– handoffs every 5s and 50 consecutive handoffs
• TCP Performance
– Scalability
• Further work
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QoS provisioning for mobile multimedia
wireless differentiated services to mobile hosts
link and node failure
multiple gateways
A Direct Routing Scheme
In Cellular IP Access Network
Sang-ick Byun and Myungchul Kim
{sibyun, mckim}@icu.ac.kr
Contents
• Introduction
• Related Work
• Cellular IP Routing Scheme
• Proposal of Direct Routing Scheme
• Implementation
• Experimental Results
• Conclusion
• References
Introduction
• Development of wireless technology and expansion
of the Internet
- Increasing demand on mobile and wireless data service
- Internet Protocol (IP) was designed without
consideration of mobility
• Mobile IP (RFC 2002)
– Solve the macro mobility management
– The mobile nodes can use the existing IP without session
interruption while the devices are moving
– It is less well suited for micro mobility management
problem
Introduction (cont’d)
• Micro mobility protocols such as [2][5][8][15] have been
proposed
• We focus on Cellular IP
– Routing policy: All packets transmitted by mobile host should
be delivered to the gateway
– Communication between mobile hosts within same Cellular IP
access network
path duplication problem
– We propose a direct routing scheme
Related Work
• C. Perkins, “IP Mobility Support” [11]
– IETF RFC 2002 (1996)
– Tunneling from HA to FA
– registration request , registration replay
 It is less well suited for “micro mobility”
• Micro mobility : frequent handoffs between small cells
• Handoff delay and service quality degradation
• R. Caceres and V. N. Padmanabhan, “Fast and Scalable
Handoffs for Wireless Internetworks” [2]
– Hierarchical mobility management scheme
– Local mobility, mobility within an administrative domain, global
mobility
– One domain foreign agent and several subnet foreign agent
Related Work (Cont’d)
• E. Gustafsson et al., “Mobile IP Regional Registration”[8]
– Gateway foreign agent (GFA)
– When the mobile host registers to its HA, MH uses the address of
GFA
– After the first registration, MH performs a local registration with
the GFA
• R. Ramjee et al., “HAWAII: A Domain-based Approach for
Supporting Mobility in Wide-area Wireless Networks”[15]
• Routing protocol for intra-domain mobility
– Domain root router
– HAWAII nodes : router + location manager using cache
Cellular IP Routing Scheme

Cellular IP Access Network
CH
HA
FA
Internet
FA
Cellular IP access network
BS
BS
BS
BS
BS
BS
IP routing
IP tunneling
Cellular IP routing
MH
Base
Station
(BS)
Gateway
 Cellular IP node that has a wireless interface
 Every node has route cache (location information about
active nodes)
 Some nodes have paging cache (location information
about idle nodes)
 Cellular IP node connected to a regular IP network
 FA of Mobile IP
Cellular IP Routing Scheme (cont’d)
• Cellular IP routing
GW
– Uplink routing : Routing from a mobile host to a gateway
– Downlink routing : Routing from a gateway to a mobile host
• Uplink routing
BS1
BS2
BS3
MH1
MH2
- All packets received from downlink neighbor used to manage a
route cache and paging cache
- After that, packet is forwarded to uplink
Route cache
Paging cache
Refreshed by
 data packet
 route-update packet
 data packet
 paging-update packet
 route-update packet
Updated by
 route-update packet
 paging-update packet
 route-update packet
Cellular IP Routing Scheme (cont’d)
• Downlink routing
- Routing from a gateway to a mobile host
Entry? YES
Forward the packet to downlink neighbor
Check route cache
NO
Does BS have a paging cache?
NO
Entry? YES
Forward to downlink neighbor
Check paging cache
YES
NO
Discard packet
Check paging cache
Broadcast
Proposal of Direct Routing Scheme
• Routing policy of existing Cellular IP
– All IP packets transmitted by a mobile host are routed from the BS
to the gateway regardless of the destination address
– Why?
All IP packets are used to manage route cache or paging cache
• Limitations of existing Cellular IP
– CASE : Communication between mobile hosts
within same Cellular IP access network
– PROBLEM
 routing path duplication
 Cutting off the routing path
Proposal of Direct Routing Scheme
(Cont’d)
• Example
X:N
Y:N
Z:Q
X:A
Y:A
Mobile IP
enabled
Internet
GW
route cache
data
A
X:O
Y:R
X:S
M
N
O
Q
R
S
Z
Y
Receiver
P
X
Sender
Proposal of Direct Routing Scheme
(Cont’d)
• Proposed Scheme
– When a packet is received, a Cellular IP node checks its
cache mapping
 If the Cellular IP node finds the cache mapping for destination
address of the packet
1. The data packet is forwarded to downlink neighbor directly
2. sends route-refresh packet or pseudo data packet to uplink
neighbors
• If the Cellular IP node can’t find the cache mapping for
destination address
1. The packet is forwarded to up-link neighbor
Proposal of Direct Routing Scheme
(Cont’d)

Direct routing scheme using route-refresh packet
X:A
Y:A
Mobile IP
enabled
Internet
GW
X:O
Y:R
Y:R
X:N
Y:N
A
Route-refresh
X:S
M
N
O
Q
R
S
Y
Receiver
P
X
Sender
Proposal of Direct Routing Scheme
(Cont’d)
• Limitation of route-refresh packet
– some packets are lost during handoff
X:A
Y:A
Mobile IP
enabled GW
Internet
X:O
Y:R
X:N
Y:Q
A
X:S
M
N
O
Q
R
S
P
route cache
data
route-refresh packet
Y
Receiver
Y
X
Sender
Proposal of Direct Routing Scheme
(Cont’d)
• Direct routing scheme using pseudo data packet
– If a BS forwards the packet to downlink neighbor directly,
the BS sends pseudo data packet to uplink neighbor
X:A
Y:A
Mobile IP
enabled
Internet
GW
A
routing cache
data
X:O
Y:R
X:N
Y:Q
X:S
M
N
O
Q
R
S
Y
Receiver
Y
P
X
Sender
Implementation
• Testbed architecture
-
Consists of four Cellular IP nodes
and two mobile hosts
-
Each BS and MH run Linux
(kernel 2.2.12)
-
IEEE 802.11b WaveLAN PC
Cards are installed at BS_2, BS_3,
MH_1, and MH_2
-
Our scheme is implemented based
upon Cellular IP 1.1 distribution
Internet
GATEWAY
Cellular IP
Access Network
BS1
BS2
BS3
MH1
MH2
GW
Experimental Results
BS1
2.0
2.0
1.6
1.6
CPU usage (%)
CPU Usage (%)
• CPU usage ratio (per a MH)
1.2
0.8
0.4
0.0
current s cheme
BS1
BS2
BS3
propos ed s cheme
(a) 400 packets/sec

BS3
MH1
MH2
1.2
0.8
0.4
0.0
GW
-
BS2
GW
current s cheme
BS1
BS2
BS3
propos ed s cheme
(b) 600 packets/sec
MH_1 sends 128byte UDP packets to MH_2 at rate of 400 and 600
packets/sec
Each BS monitor the CPU usage ratio during 30 seconds
RESULT : CUP usage ratio is reduced in GW and BS_1
Experimental Results (cont’d)
• Robustness
BS2
GATEWAY
GATEWAY
BS1
BS1
BS3
Data
BS3
MH1
MH2
Data
MH1
MH2
(a) Existing Cellular IP
-
BS2
(b) Proposed Scheme
The gateway stop running in the middle of packet transmission from MH_1
to MH_2.
1. In existing Cellular IP scheme, packets are not delivered after that time
2. In proposed scheme, all packets are delivered without any interruption
GW
Experimental Results (cont’d)
• Bandwidth consumption using VIC
Bandwidth
Consumption
(Kbps)
Bandwidth
Consumption
(Kbps)
600
400
200
0
eth0
eth1
(a) gateway
-

Existing Scheme
Proposed Scheme
600
400
200
0
eth0
eth1
(b) BS_1
eth2
800
Existing Scheme
Proposed Scheme
600
400
200
0
eth0
wvlan0
(c) BS_2
BS2
BS3
MH1
MH2
800
Bandwidth
Consumption
(Kbps)
800
800
Bandwidth
Consumption
(Kbps)
Existing Scheme
Proposed Scheme
BS1
Existing Scheme
Proposed Scheme
600
400
200
0
eth0
wvlan0
(d) BS_3
The experiment is carried out using VIC 2.8ucl-1.1.3, in order to measure the
performance of practical application
The sender, MH_1, is equipped with a capture board and a video camera
While video data is transmitted from MH_1 to MH_2, the Cellular IP nodes
monitor bandwidth consumption in each network interface.
RESULT : Bandwidth consumption between crossover BS and gateway is
reduced by 50%
Experimental Results (cont’d)
• Packet loss with handoff
Packet loss per handoff
0.30
exis ting s cheme
0.25
propos ed s cheme
GW
0.20
BS1
0.15
0.10
0.05
BS2
BS3
MH1
MH2
0.00
25
50
100
150
Number of TX packet per s econd (pps )
-
-

The sender, MH_1, sends 100byte UDP packets at rates of 25, 50, 100, and
150 packet/sec
MH_2 handoffs between BS_2 and BS_3 every five seconds
The UDP packets are transmitted for 100 seconds and MH_2 handoffs 20
times
RESULT : Our scheme does not deteriorate the existing Cellular IP in terms
packet loss with handoff
Conclusion
• Advantages of a direct routing scheme
- Mobile host use shortest path within Cellular IP access
network
- Resource saving in BSs between gateway and crossover
BS
 CPU time for packet processing is reduced
 Bandwidth consumption is reduced
- Robustness is high
• Future work
- Enlargement testbed
- Studies the effects of proposed scheme on multimedia
applications
References
[1] M. Albrecht, M. Frank, P. Martini, M. Schetelig, A. Vilavaara, and A. Wenzel, “IP
Services over Bluetooth: Leading the Way to a New Mobility,” Conference on Local
Computer Networks (LCN '99), 1999
[2] R. Caceres and V.N.Padmanabhan, “Fast and Scalable Handoffs for Wireless
Internetworks,” ACM Conference on Mobile Computing and Networking (Mobicom’96),
1996.
[3] C. Castelluccia, “Extending Mobile IP with Adaptive Individual Paging: A Performance
Analysis,” Computers and Communications, Proceedings. ISCC 2000. Fifth IEEE
Symposium Page(s): 113 –118, 2000
[4] S. Das, A. Misra, S. K. Das, and P. Agrawal, “TeleMIP: Telecommunication-Enhanced
Mobile IP Architecture for Fast Intradomain Mobility,” IEEE Personal Communications,
Aug. 2000
[5] A. T. Campbell, J. Gomez, S. Kim, Z. Turanyi, C-Y. Wan, and A. Valko, “Design,
implementation, and evaluation of cellular IP,” IEEE Personal Communications, Vol.7
Issue. 4, Aug. 2000, pp. 42 –49
[6] A.T. Campbell, J. Gomez, C-Y. Wan, S. Kim, Z. Turanyi, and A. Valko, "Cellular IP,"
Internet Draft, draft-ietf-mobileip-cellularip-00.txt, January 2000.
[7] A. T. Campbell, S. Kim, J. Gomez, C-Y. Wan, Z. Turanyi, and A. Valko, “Cellular IP
Performance,” draft-gomez-cellularip-perf-00.txt, Oct. 1999
[8] E. Gustafsson, A. Jonsson, and C. Perkins, “Mobile IP Regional Registration,” Internet
Draft, draft-ietf-mobileip-reg-tunnel-04.txt, March 2001; work in progress
[9] C. Perkins and D.B. Johnson, “Route Optimization in Mobile IP,” Internet Draft, draftietf-mobileip-optim-09.txt, Feb. 2000.
References (Cont’d)
[10] C. Perkins and D.B. Johnson, “Mobility Support in Ipv6,” Internet Draft, draft-ietfmobileip-ipv6-07.txt, 1998.
[11] C. Perkins, “IP Mobility Support,” IETF RFC 2002, Oct. 1996
[12] J. Postel, “Internet Control Message Protocol,”, IETF RFC 792, Sep. 1981
[13] J. Postel, “User Datagram Protocol,” IETF RFC 768, Aug. 1980
[14] R. Ramjee, T. F. La Porta, L. Salgarelli, S. Thuel, and K. Varadhan, “IP-Based Access
Network Infrastructure for Next-Generation Wireless Data Networks,” IEEE Personal
Communications, Vol.7 Issue. 4, Aug. 2000, pp. 34-41
[15] R. Ramjee, T. La Porta, S. Thuel, K. Varadhan, and S.Y. Wang, “HAWII: A Domainbased Approach for Supporting Mobility in Wide-area Wireless Networks,” IEEE
International Conference on Network Protocols, 1999.
[16] András G. Valkó, "Cellular IP: A New Approach to Internet Host Mobility," ACM
Computer Communication Review, Jan. 1999.
[17] The MGEN Toolset, http://manimac.itd.nrl.navy.mil/MGEN/
[18] Instruction to Mobile IP, http://www.cisco.com
[19] Mbone Conferencing Applications, http://www-mice.cs.ucl.ac.uk
[20] Cellular IP, http://www.comet.columbia.edu/cellularip