IP over Wireless ATM
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Transcript of IP over Wireless ATM
HSN ‘98‘98.2.12 ~ 14, 전주
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IP over Wireless ATM
1998. 2. 13.
김 용 진
한국전자통신연구원
HSN ‘98‘98.2.12 ~ 14, 전주
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Outline
Background Mobile IP IP over ATM Location Management in WATM IP over Wireless ATM
HSN ‘98‘98.2.12 ~ 14, 전주
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Background
Motivation Increase of IP service demands
# of hosts on the Internet has doubled per year # of web servers has doubled every 20 weeks From best efforts service to QoS guaranteed real-time multimedia services (-> ATM)
Information infrastructure based on ATM technology Needs for development of new services Needs for supporting legacy communication services (-> IP)
Communication evolution into wired/wireless integrated environment Rapid increase of mobile phone service users Needs for mobile multimedia services (-> Mobile ATM)
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IP Mobility Support over ATM
MIP over ATM = MIP + IPOA Mobility support in IP layer Connectionless oriented mobility support
IP over WATM = IPOA + WATM Mobility support in ATM layer Connection oriented mobility support
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Mobile IP
Internet RFCs RFC 2002 : IP Mobility Support RFC 2003 : IP Encapsulation within IP RFC 2004 : Minimal Encapsulation within IP RFC 2005 : Applicability Statement for IP Mobility Support RFC 2006 : The Definitions of Managed Objects for IP Mobility
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Mobility Problems and Solutions
Mobility problems A name is a location-independent id An address reflects a host’s point of attachment to the network In IP, DNS(Domain Name System) is used for name-to-address
translation In MIP, the binding is a function of time
-> IP layer needs mobility control
Network layer solution architecture Two-tier addressing
Two internet addresses with each mobile host (Home address, Care-of address) - Home address for protocol processing - Care-of address for routing
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MIP Components
R
R
Care-of address
Home address
CN
InternetHome network
Foreign network
MN
128. 8. 128
. . 2 . . 3
FA
HA
MN
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Mobility Control
Advertisement
Registration Request
Registration Reply
Datagram
Tunneled datagram
MN
Decapsulation
Datagram
Encapsulation
FA HA
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Routing Optimization
Home network
Foreign networkf
Cacheg
LD
MH
S
Source
Address translation agent
Location directory
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IP vs. ATM
IP
Connectionless Currently No QoS Destination based routing Future, scalability Problem Moderate overhead
Mobile IP Variable packet size Multicast/broad cast
ATM
Connection Oriented QoS Support Fast Switching Scalable High overhead for IP over AT
M Wireless ATM Fixed packet size Yes but requires VC mesh or
MCS
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IP over ATM
IPOA Paradigm
Layered Model
Classical IP over ATM
LAN Emulation(ATM Forum)
(IETF)
Multi-protocolover ATM
(ATM Forum)
Next Hop Resolution Protocol(IETF)
Integrated Model
I-PNNI(ATM Forum)
IP & TagSwitching (IETF)
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Characteristics of Layered Model
IP overlays ATM with layer 3 (layered routing) ARP (IP, ATM) is required IP routing protocol in IP routers ATM routing protocols are used Modifications in ATM control SW are not required Inefficient multicasting Standardized Specs.
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Characteristics of Integrated Model
Integrated routing protocol ARP (IP, ATM) is not required ATM routing protocols are not used Modifications in ATM control SW are required Efficient multicasting Standardized Specs. are in progress
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Comparison : Route Selection
I-PNNII-PNNI
OSPFMPLS
PNNI
OSPFNHRP
Classic OSPF
PNNI PNNI PNNI
OSPF
IP
ATMIP
OSPF OSPF OSPF
OSPF OSPF OSPF OSPF
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Comparison :Internode Communication Protocols
Type ofcommunication
MPLS NHRP I-PNNI
OSPFRouting OSPF/PNNI
I-PNNI
Signaling TDP,IFMP,...
PNNI I-PNNI
Address resolution
NHRP
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IP over WATM (I)
IPaddr(= AP) --> (ATMvisiting_addr = AP)
i) IPaddr -- ARP -> ATMhome_addr -- MC(t) -> ATMvisiting_addr
ii) IPaddr ----- ARP*(t) -------> ATMvisiting_addr
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IP over WATM (II)
IP Over WATM = IPOA + WATM
cf) MIP over ATM
NHRP
(X) MPLS
(X) I-PNNI
Mobility ControlMC(t)
Home agent
Foreign agent
NHRP
MPLS
I-PNNI
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Location Management in WATM
LM enables the network to communicate with MN by managing the information about the location of the MN
LM = Mobile tracking + Mobile locating Mobile Tracking
Network elements updating procedure about the location of mobile entities
Mobile tracking = Mobile registration + updating
Mobile Locating The procedure by which a network node determines the
location of the MT for the delivery of incoming calls May be executed explicitly prior to call setup or may be an
integral part of the call setup procedure
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Two Approaches for the LM in WATM
Mobile PNNI scheme LR scheme
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Mobile PNNI Scheme
Extension of the PNNI routing protocol to support MN Use of the PNNI routing protocol for reachability information Scope parameter for the restriction of RI update
No explicit “search” procedure prior to call setup Connection setup combined with mobile locating
Requires additional routing optimization process
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PNNI Routing Protocol Overview
Hierarchical peer groups with Peer Group Leaders(PGLs) and Logical Group Nodes(LGNs)
Exchange of information for topology, load and reachability by using Protocol Topology State Packet (PTSP)
Reachability summarized and advertised by PGLs
ATM switch
Peer group leaderl=1
l=2
l=L
A B
A.1 A.2B.1
B.2 B.3
A.1.1 A.1.2
A.1.3
A.1.4A.2.1
A.2.2 B.1.1 B.1.2
B.1.3
B.1.4B.1.5
B.2.3
B.2.1
B.2.2
B.3.1 B.3.2B.3.3
B.3.4
B.3.5B.3.6
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PNNI Extension
Enhancement of the PNNI routing protocol for the exchange of reachability information of mobile users
Three new parameters are defined Scope S is used to set the stop point for reachability informatio
n propagation Ancestors-are-sibling level aij of nodes i and j is the level at whi
ch the ancestors of the two nodes i and j belong to the same peer group
The neighborhood Gi of a node i is defined to include all nodes j such that aij >= S
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Mobile Tracking
Mobile registers at switch n
New location outsidethe neighborhood
of the old location ?ano < S
Send registrationto home swtich
Send registration to oldswitch to set a pointer at
to the old switch to forwardcalls to new location
Send registration to home switch ;Send registration to old switch
to set a pointer at the old switch to forward calls to new location
(if home = old, only one registration is needed)
Yes No
Power on/offregistration
Registrationresulting from a move from mode o to new node n
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Connection Setup/Mobile Locating
Calls arrives at the origination switch
Call arrival wasafter reachability
update is complete
Call is routed directly to the mobile
Call is routed to the oldlocation and then
to the current locationof the mobile
Call arrival wasafter reachability
update is complete
Call is routed to the homeswitch and then
to the current locationof the mobile
Call is routed to the homeswitch, then to the old location
and finally to the currentlocation of the mobile
Call arrival wasafter home switch
receives registrationfollowing a move or the home is the
old location
Called mobileis in its home
neighborhood ?ahv >= S
Calling party is outside thecalled mobile’s neighborhood
acv < S
Calling party is within the
called mobile’s neighborhood
acv >= S
No
No
No
No
Yes
Yes
Yes
Yes
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LR Scheme
Application of cellular LR scheme to PNNI-based hierarchical ATM networks Hierarchical LR DBs Scope parameter for the restriction of LR provisioning level
Isolate effect for mobility from PNNI routing protocol Explicit “search” procedure prior to call setup
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LR Architecture
l=S=2
l=L
A.L B.L
A.1.L A.2.L B.1.L B.2.L B.3.L
A.1.1 A.1.2
A.1.3
A.1.4 A.2.1
A.2.2 B.1.1 B.1.2
B.1.3
B.1.4B.1.5
B.2.3
B.2.1
B.2.2
B.3.1 B.3.2 B.3.3
B.3.4
B.3.5B.3.6
BSBSA.1.2.5
A.1.1.4 A.1.2.3
B.2.2.5 ATM switch
LocationRegister
A.2.2.5
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Mobile Tracking in the LR Scheme
Mobile registers at switch
Updates are propagatedfrom Lth level LR to
Sth level LR ; Home LR is informed about the current Sth level LR.
Updated are propagated from Lth level LR to
aonth level LR at the new
neighborhood ; Cancellations are propagated from
Lth level LR to aon + lth level LR at
the old neighborhood.
Updates are propagated from Lth level LR to
Sth level LR at the new neighborhood ; Home LR is informed about the new Sth
level LR ; Cancellations are propagated from Lth level
LR to Sth level LR at the old neighborhood.
aon >= S NoYes
Power on/offregistrationat switch n
Registrationresulting from amove from nodeo to new node n
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Mobile Locating in the LR Scheme
Callingparty’s
switch(c)
Called mobile’s current switch(v)
Home switch of the called mobile(h)
l = I
l = S
l = L
LOCREQ
LOCREQ
LOCREQ
LOCREQ
LOCREQ
LOCREQ
LOCREQ
LOCREQResponse
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Comparison
Item Mobile PNNI LR
Address space partition Not required Required
Resource allocation for call setup
Not optimized Optimized
Application to public network
Applicable Not applicable
Modification of ATM signaling and routing
Required Not required
Performance Superior in low CMR Superior in high CMR
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Performance & Cost Issues
LM cost = Mobile tracking cost + Mobile location cost Mobile tracking (locating) cost
= Computational cost (DB access)
+ Communication cost (signaling & routing) For performance analysis, exact models of network and mobile no
de are required