Wireless Data Topics

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Transcript Wireless Data Topics 

MobileNAT
(Mobility across Heterogeneous
Address Spaces)

Presented by Kundan Singh

(Columbia University)


Joint work with Milind Buddhikot,
Adiseshu Hari and Scott Miller

Agenda
Motivation
Architecture
Implementation
Comparison with
current approaches
Summary
(30 slides, 60 min)
Current Trends
Explosive growth in
connected devices
 Heterogeneity

802.11
• Access: 802.11, 3G,
•
•
Private address
3G
13-Oct-03
MobileNAT/IRT group meeting
Ethernet
Provider; billing
Address space
 IPv4 vs IPv6
 Public vs Private
2
Project IOTO
13-Oct-03
http://www.bell-labs.com/~mbuddhikot/IOTAProject/IOTA.htm
MobileNAT/IRT group meeting
3
The goal
NAT
(5)
Routed
IP Network
www.cnn.com
Preserve session for
1.
inter access-point
2. inter sub-net
3.
inter-NAT
4.
to 3G network
5.
to public network
PDSN/3G
Internet
(4)
NAT
Public Addr A
NAT
Private Address
Space
(3)
802.11
802.11
(1)
Ethernet
Access-point
(2)
Router
Router with NAT
13-Oct-03
MobileNAT/IRT group meeting
4
MobileNAT
(Mobility across Heterogeneous
Address Spaces)

Presented by Kundan Singh

(Columbia University)


Joint work with Milind Buddhikot,
Adiseshu Hari and Scott Miller

Agenda
Motivation
Architecture
Implementation
Comparison with
current approaches
Summary
Problem with IP address
TCP association

128.59.16.149
135.180.32.4
80
1733
• Host identification
• Routing information
CN (corresponding node)

128.59.16.149
moves
Change in IP address
breaks TCP/socket
connection
MN
MN
(mobile node)
135.180.32.4
135.180.54.7
135.180.32.4
128.59.16.149
1733 80
135.180.54.7
128.59.16.149
1733 80
13-Oct-03
IP address overloaded
MobileNAT/IRT group meeting
Convention:
Source IP
Destination IP
SP
DP
6
Two addresses

128.59.16.149
135.180.32.4
80
1733
Two IP addresses
• Virtual IP (fixed host-id)
• Actual IP (routable; changes)
CN
128.59.16.149
Application
Socket
TCP/UDP
IP
V=135.180.32.4
Anchor node (AN)
MN
moves
Addr “V”
MN
Shim Layer
135.180.32.6
A=135.180.54.7
135.180.32.4
128.59.16.149
1733 80
135.180.32.4
128.59.16.149
1733 80
13-Oct-03
Actual IP
Virtual IP
MobileNAT/IRT group meeting
Addr “A”
Net IF
7
Packet forwarding mechanisms:
tunneling or translation
CN
128.59.16.149
CN
128.59.16.149
135.180.32.4
128.59.16.149
128.59.16.149
135.180.32.4
128.59.16.149
135.180.54.7
V=135.180.32.4
AN
128.59.16.149
135.180.32.4
moves
V=135.180.32.4
AN
128.59.16.149
135.180.54.7
moves
MN
A=135.180.54.7
MN
A=135.180.54.7
Translation
Tunneling
• Outer: CN=>A or HA=>A
• Inner: CN=>V
• Header overhead
• More processing overhead
• Not an issue if NAT1 is already
present
1NAT is described later
13-Oct-03
MobileNAT/IRT group meeting
8
Address allocation using DHCP
Virtual and actual IP
allocated using DHCP
 New DHCP options

• MN sends current virtual IP
DHCP server
•
DHCP relay agent
10.0.1.x
10.0.2.2
•
address (or 0.0.0.0 if none)
in the request
Server sends the allocated
actual and virtual IP
addresses in the response
Actual IP is allocated based
on relay agent IP
10.0.1.5
10.0.2.x
10.0.2.9
13-Oct-03
MobileNAT/IRT group meeting
9
Overview of NA(P)T

CN
Packet processing rules need to be
changed in the event of mobility
128.59.16.149
Internet
Public Addr
135.180.32.1-7
Packet processing
rule 135.180.32.4
128.59.16.149
7088 80
out
10.0.1.5
128.59.16.149
1756 80
In-1
NAT
Private Address Space
(10.0.0.0-10.255.255.255)
10.0.7.x
10.0.1.x
10.0.2.x
10.0.1.5
13-Oct-03
MobileNAT/IRT group meeting
10
Mobility manager and MIDCOM
MIDCOM to control NAT
rules
Mobility manager IP in DHCP
response


Internet
Change of lease
DHCP
server
Mobility
manager
NAT rules
NAT
relay
relay
relay
10.0.1.x
10.0.2.x
10.0.1.5
13-Oct-03
MobileNAT/IRT group meeting
11
Example
Address assignment
 Packet flow when MN is private and CN is public
 MN moves to a new subnet
 Packet flow after mobility to a new subnet
 Packet flow when MN and CN are in the same NAT domain
 Packet flow when MN is private and CN is public and MN
moves to new NAT domain

13-Oct-03
MobileNAT/IRT group meeting
12
Address assignment
Mobility manager
DHCP request
(my virtual IP = 0.0.0.0)
(my Mac address)
DHCP server
NAT
DHCP response
(your virtual IP = 10.128.0.2)
(your actual IP = 10.0.1.5)
DHCP
server
NAT
Internet
13-Oct-03
MobileNAT/IRT group meeting
13
Packet flow
10.128.0.2
128.59.16.149
1756 80
128.59.16.149
10.128.0.2
80
1756
Applicatio
n
Socket
TCP/UDP
Shim
10.0.1.5
128.59.16.149
1756 80
Shim
128.59.16.149
10.0.1.5
80
1756
NAT
135.180.32.4
128.59.16.149
7088 80
NAT
128.59.16.149
135.180.32.4
80
7088
(1)
IP
10.128.0.2:1756
Addr “V”
SHIM Layer
10.0.1.5:1756
Addr “A”
10.0.1.5:1756 135.180.32.4:7088
(2)
(3)
Internet
Net IF
NAT

13-Oct-03
MobileNAT/IRT group meeting
CN
NAT picks up an
external IP and port
14
Inter-subnet mobility
Mobility manager
change
DHCP request
(my virtual IP = 10.128.0.2)
DHCP server
(my Mac address)
NAT rules
10.0.2.7
S:10.0.1.5:1756 D:128.59.16.149:80
S:135.180.32.4:7088 D:same
DHCP response
(your virtual IP = 10.128.0.2)
(your actual IP = 10.0.2.7)
10.0.2.x
DHCP
server
NAT
Internet
CN
10.0.1.x
13-Oct-03
MobileNAT/IRT group meeting
15
Packet flow after the node moves
10.128.0.2
128.59.16.149
1756 80
128.59.16.149
10.128.0.2
80
1756
Applicatio
n
Socket
Shim
10.0.2.7
128.59.16.149
1756 80
Shim
128.59.16.149
10.0.2.7
80
1756
NAT
135.180.32.4
128.59.16.149
7088 80
NAT
128.59.16.149
135.180.32.4
80
7088
(1)
TCP/UDP
IP
10.0.2.7:1756 135.180.32.4:7088
Addr “V”
SHIM Layer
Addr “A”
(3)
Net IF
(2)
NAT

13-Oct-03
MobileNAT/IRT group meeting
Internet
CN
MN application or CN do
not know about change in
actual IP
16
Intra-domain sessions
CN
A=10.0.4.9
V=10.128.0.2
A=10.0.2.7
NAT
MN
Moves
V=10.128.0.2
A=10.0.1.5
MN

Optimization: new signaling message between two MobileNAT clients
to route the packets directly
13-Oct-03
MobileNAT/IRT group meeting
17
Inter-domain mobility




Mobility manager of visited NAT fetches the existing connection
mapping from mobility manager of the home NAT
If MN moves to public address space, Shim layer acts as visited NAT
Dynamic home agent: use visited NAT as home NAT for new session
Tunneling between visited and home NAT
MN
Visited NAT
moves
Internet
MN
Home NAT
13-Oct-03
MobileNAT/IRT group meeting
CN
18
MobileNAT
(Mobility across Heterogeneous
Address Spaces)

Presented by Kundan Singh

(Columbia University)


Joint work with Milind Buddhikot,
Adiseshu Hari and Scott Miller

Agenda
Motivation
Architecture
Implementation
Comparison with
current approaches
Summary
Implementation: client (Win XP/2000)
10.128.0.2 /
255.0.0.0
Application
MobileNAT
Client
Server Client
Socket
TCP/UDP
MobileNAT
Client
MobileIP
Client
IP
Addr “V”
Shim Layer
10.0.1.5 /
255.255.255.0



DHCP
server - client
Addr “A”
Net IF
Network and
interface
selector
Unified mobility client (on-going work)
Shim-layer driver to capture DHCP packets and translate IP
addresses
MobileNAT client application acting as DHCP client and server
Handles ARP for nodes in other sub-nets
13-Oct-03
MobileNAT/IRT group meeting
20
Client architecture
Graphical User Interface & Monitoring
OS
PPP Support
User Level
MIP State
Machine
Network
Detection
Network
Selection
Mobile
NATClient
Interface Abstraction Layer/API
Ethernet
802.11
PPP
CDMA2000
Sierra
3G1xRTT
OS Kernel Level
Serial Driver
AT Command Set
TCP/IP Protocol Stack
VPN/IPSec Client Driver
Multi-interface Mobility Client Driver
IS-835
Shim
PPP
Interface
13-Oct-03
Ethernet
Interface
802.11
Interface
Virtual
MobileIP
Adaptor
MobileNAT/IRT group meeting
VPN/
IPSec
Control
New code developed,
Specifically for
3G-802.11 integration
VPN/IPSec integration
(e.g. Lucent IPSec
Client)
Interaction with
Existing Windows
OS modules
21
User interface

Approximately 45,000 lines of code, 13,000 of which are Windows NDIS
kernel networking code
13-Oct-03
MobileNAT/IRT group meeting
22
Implementation: DHCP server and NAT (Linux)
Virtual IP range
Actual IP range
NAT connection
tracking
DHCP server
PRE-ROUTING
Destination NAT
POST-ROUTING
Source NAT
DHCP server to allocate virtual and actual IP
 Actual IP is based on subnet of DHCP relay agent
 MM is integrated into DHCP server
 NAT using netfilter, iptables, ip_conntrack and ip_nat
modules

13-Oct-03
MobileNAT/IRT group meeting
23
MobileNAT
(Mobility across Heterogeneous
Address Spaces)

Presented by Kundan Singh

(Columbia University)


Joint work with Milind Buddhikot,
Adiseshu Hari and Scott Miller

Agenda
Motivation
Architecture
Implementation
Comparison with
current approaches
Summary
Similarities/Differences with current
proposals

Translation mode vs. tunneling
• Packet size vs processing overhead
• Two addresses per MN; can afford since private addresses
• No external FA needed

Signaling
• Using DHCP (new options) and a per-domain Mobility Manager (MM)

Routing path
• No change in routers or CN; but change in MN, NAT and DHCP server
• Dynamic home agent (I.e., the NAT)
13-Oct-03
MobileNAT/IRT group meeting
25
Comparison to existing schemes
Schemes considered in following chart
 Mobile IP
• Extensions: Location Register (MIP-LR), Route Optimization (MIP-RO)

Micro-mobility schemes




Cellular IP
Hawaii
Intra-Domain Mobility Protocol (IDMP)
Hierarchical Mobile IP (HMIP)
IPv6
 Application level mobility mechanism

• SIP

Virtual NAT
• Similar address translation in the client stack
• Targeted for connection migration where both end-points implements vNAT
13-Oct-03
MobileNAT/IRT group meeting
26
Comparison chart
MIP
Mobile
NAT
CIP
Hawaii HMIP
(RR)
IDMP
TeleMIP
MIP
LR
MIP
RO
SIP
IPv6
MIP messaging Y
N
Y
Y
Y
-
-
N
Y
N
N
Inter-tunnel
Y
Y
Y
Y
Y
N
Y
N
O
O
N
Intra-tunnel
-
N
N
Y
Y
-
-
-
O
O
N
Paging
O
Y
Y
Y
Y
-
-
N
Y
UD
N
Host ID
HA
HA
CoA
CoA
LCoA
-
-
SIP
HA
CoA
virtual
signaling
Y
Data
Y
Y
Y
Y
Y
Y
Y
DHCP/ Y
MM
CN modify?
N
N
N
N
N
Y
Y
-
N
N
Y
MN modify?
Y
Y
Y
Y
Y
Y
Y
-
Y
Y
Y
Router modify? FA
Y
Y
FA
FA
-
-
-
O
N
N
NAT support
Y1
Y
Y
Y
Y
IN
IN
Y
IN
Y
IN
Non-mobile IP
nodes
Y
N
Y
Y
Y
-
-
-
Y
Y
IN
Triangular route Y
Y
Y
Y
Y
N
N
N
N
N/Y
N
Y: yes N: no - :N/A O: optional IN:independent UD: Under Development
1: We assume Mobile IP with UDP tunneling for NAT
MobileNAT/IRT group meeting
13-Oct-03
Virtual
NAT
27
Mobile NAT Advantages

Problems in existing approaches
•
•
•
•
•

Huge infrastructure change (CIP, IPv6, routers, even deploying FA)
Not much discussion on optimizing intra-domain sessions
Require tunneling overhead, inter, intra or both
Triangular routing
Modification in CN
MobileNAT approach
• Addresses rapid growth in end-devices, which most likely will have private
•
addresses due to slow deployment of IPv6
Assume the presence of NA(P)T in a domain
 Roaming and services across heterogeneous address spaces
 Reduce problem space to only private address space
• Choice between tunneling and address translation
 Addresses bandwidth limitations of wireless links
• Use existing protocols (DHCP, ICMP) for signaling
• Discourage changing routing infrastructure
• Can co-exist with MobileIP
13-Oct-03
MobileNAT/IRT group meeting
28
On-going work





Scalability:
• Subdivide domains into smaller NAT-ed domains
• Multiple NATs per domain
Security
• DHCP authentication and Access-point authentication/encryption
• Works with IP-sec (AH mode and UDP tunnel) and SSL
Paging:
• Re-use of existing IP-multicast based paging
Possible deployment issues
• Changing every MN driver (similar to Mobile IP)
• Mobility to 3G network
• Location information distribution
• Allow incremental deployment
Other issues
• Does not solve NAT problems where application layer message uses IP address
•
•
•
13-Oct-03
(FTP, SIP, RTSP)
Fast hand-off for micro-mobility
Intra-domain sessions on inter-domain mobility
Combined MobileIP and MobileNAT client
MobileNAT/IRT group meeting
29
Summary

Main Ideas
•
•
•
•
•
•

Virtual IP for host identification; actual IP for routing
Address translation in client as well as in NAT
Existing protocols like DHCP for signaling
Mobility manager to handle nodes in a domain
NAT acts as a dynamic home agent
Inter-NAT packet flow for inter-domain mobility
No change in routers or no need for FA
• Change In MN, NAT and DHCP server

Demonstrated a simple inter-subnet mobility
13-Oct-03
MobileNAT/IRT group meeting
30
Survey of existing mobility approaches for
private/public addresses
BACKUP SLIDES
Mobile IP for macro mobility
(1)

CN
Triangular routing
HA
Internet
• Route optimization

Slow handoff
• Hierarchical mobility
• Tunneling (HMIP)
• Mobile specific routing
(4)
(2)
MN
FA
(1) CN=>HA
(2) HA=>FA
CN=>HA
(3) CN=>HA
(4) HA=>CN
(CIP, Hawaii)
(3)
MN

Signaling overhead
• Paging (CIP, Hawaii,
HMIP)

Firewall, etc.
• Reverse tunneling
13-Oct-03
MobileNAT/IRT group meeting
32
Mobile IP with NAT
(2) CN=>HA
CN
Internet
Oubound traffic
NAT
(1) register;
establish port
mapping
UDP port mapping
HA
created during register
 HA finds that FA is
behind NAT
(3) HA=>NAT (UDP)
CN=>HA (IP)  HA uses IP in UDP
tunnel

(4) NAT=>FA (UDP)
CN=>HA (IP)
FA
MN
13-Oct-03
MobileNAT/IRT group meeting
33
Micro mobility: Cellular IP
CoA is of gateway (FA)
 No change in CoA
within domain
 Gateway converts
cellular IP to IP
 Network elements
snoop on data packets
from MN to GW; set
the reverse route from
GW to MN
 Paging to discover idle
MN
 NAT can be at gateway

CN
HA
Internet
gateway
Intra-domain cellular
IP (non-IP) cloud
MN
MN
Id = HA
13-Oct-03
MobileNAT/IRT group meeting
34
Micro mobility: Hawaii
CN=>HA
CoA is of root router
(FA)
 Host specific route in
IP
 Path setup tradeoff

CN
HA
Internet
HA=>CoA
CN=>HA
root router
IP cloud
• Explicit signal from MN to
HA=>CoA
CN=>HA
•
MN
update route
Packet loss, reorder,
handoff latency
Paging (IP multicast) to
discover idle MN if no
routing information
 NAT can be at root
router

MN
Id=CoA
13-Oct-03
MobileNAT/IRT group meeting
35
Micro mobility: Hierarchical mobile IP
CN=>HA
HA
Internet
HA=>GFA
CN=>HA
GFA
GFA=>FA
CN=>HA
FA
MN
FA
MN
13-Oct-03
Two levels
 Works with non-mobile
(but) IP traffic in
domain
 Paging
 Two IP addresses
(GFA and FA) per MN
 NAT can be at GFA
 High level network of
FA (preferably tree)
above IP; registration
updates at optimal
point in the tree

CN
MobileNAT/IRT group meeting
36
Micro mobility: IDMP/TeleMIP
CN=>HA
CN
Internet
MA
FA
MN
FA
MN
13-Oct-03
MA acts as gateway to
HA
internet
 Subnet agent (e.g.,
HA=>MA (GCoA) DHCP or FA) sends
CN=>HA
domain info
 MN registers
MA=>FA (LCoA)
GCoA=MA @ HA;
CN=>HA
LCoA=FA @ MA; two
level addressing
 Similar to HMIP except
multiple MA allowed for
load balancing
 MA does NAT

MobileNAT/IRT group meeting
37
MIP Location Registers
CN
Get and cache CoA of
MN for given TTL
HLR
Internet
(4)
VLR
(3)
MN
13-Oct-03
Avoids encapsulation
 Modify CN
 New VLR deregisters
old VLR
 If VLR runs out of
address inform HLR;
which informs CN to
use tunnel from CN to
VLR
 If MN moves before
TTL, (1) inform VLR,
HLR that informs CN
(2) inform CN directly
(3) old VLR relays to
new

MobileNAT/IRT group meeting
38
SIP application level mobility
Initial INVITE
CN
Home
SIP server
Internet
Re-INVITE
Re-REGISTER
MN
13-Oct-03
Only for
VoIP/multimedia calls
 No change in existing
infrastructure
 NAT traversal (next
slide)

Initial INVITE
MN
MobileNAT/IRT group meeting
39
Middle box communication (midcom)
Internet
signaling
midcom
NAT
server
signaling
media
host
13-Oct-03
Application specific proxy
server controls NAT/firewall
port binding/hole
 Separate NAT/ALG
functionality
 Proxy snoops or modifies
signaling
 Signaling traffic allowed on
fixed port; media on
dynamic port
 Works with SIP
 No incentive to install

CN
MobileNAT/IRT group meeting
40
Simple Traversal of UDP through NAT (STUN)
stun
server
CN

(2)

Internet
(6)
(3)

NAT

(5)
(4)
(1)


host
Host sends a packet to stun
server
NAT converts internal IP to
external IP
Responds with source IP of
packet (i.e., external)
Host knows that its external IP
is not same as internal
It uses external IP/port when
advertising in SDP
Does not work for symmetric
NAT
• external IP for same host different
for connection to different external
host
13-Oct-03
MobileNAT/IRT group meeting
41
Realm Specific IP (RSIP)

CN
Internet
CNNAT
NAT
NAThost
<CNNAT>



Get an external address from
NAT for this private host
Tunnel packets between NAT
and private host
Works for various combinations
of multiple RSIP gateway, NAT,
NAT with RSIP, and RSIP hosts.
Need RSIP aware host
host
13-Oct-03
MobileNAT/IRT group meeting
42
Mobility in IPv6
CN
(1) First IPv6 packet
CN=>HA
(3) IPv6
(4)
destination
subsequent option
packets

HA
Address autoconfiguration
• Always obtain a CoA in FN
• Net part+local part
• No FA needed
Internet
(2) Tunneled
HA=>CoA
CN=>HA

Route optimization
• IPv6 Destination option to
•
MN

CN and HA
CN caches CoA of MN and
sends directly
Hierarchical MIPv6
• Global address = mobile
•
13-Oct-03
MobileNAT/IRT group meeting
server’s network; allow
change in MS
Local address known to
mobile server
43
Mobile NAT: motivation

Problems in existing approaches
•
•
•
•
•

Not much discussion on optimizing intra-domain sessions
Require tunneling overhead, inter, intra or both
Triangular routing or modification in CN
Huge infrastructure change (CIP, IPv6, even deploying FA)
...
What MobileNAT does?
•
•
•
•
•
•
•
13-Oct-03
Reduce problem space to only private address space MN
Assume the presence of NA(P)T in a domain
Choice between tunneling and address translation
Use existing protocols (DHCP, ICMP) for signaling mobility
Discourage changing routing infrastructure
Can co-exist with MobileIP, Hawaii and IPv6 (?)
Provide roaming and services across heterogeneous address spaces
demarked by address translation devices
MobileNAT/IRT group meeting
44
Mobile NAT: intra-domain

CN
• HA is in NAT (MN is private)
• FA is in MN (driver, kernel)
Internet
CN<=>A

Virtual vs routable address
• Virtual: fixed private address “a”
A=a
NAT
•
IP cloud
CN<=>b
a/b
No explicit HA or FA
•

MN
exposed to application on MN
Routable: dynamic private address
“a” or “b” using DHCP
Transport sessions between CNA
(external), CNa (internal)
Address translation
• NAT (Aab), MN (ba)
a/a
MN
Id=Private
13-Oct-03

Tunneling
• NATMN
MobileNAT/IRT group meeting
45
Mobile NAT: inter-domain
Inter-NAT tunnel or relay
 MN moves a/a=>a/c
 NAT1 and NAT informed
 Translation

CN
Internet
B=a
CN<=>A
NAT2
• NAT1: AaB
• NAT2: Bac
• MN: ca
A=a
NAT1
CN<=>b
a/c
MN

Issues
• Multiple “a” in NAT2
 But unique map Ba
• Does IP security work (?)

a/a
13-Oct-03
MN
Like Mobile IP
• FA=NAT2,HA=NAT1
• At most two level of NATs
MobileNAT/IRT group meeting
46
Mobile NAT: intra-domain sessions
CN

• MN2 sends to NAT; destination “a”
• NAT responds router redirect “b” (?)
• MN2 now sends to MN1
Internet
A=a

NAT
MN2
MN1

a/b
active session
MN1
MN1 moves a/b=>a/c
•
•
•
•
•
d/e
a/c
MN1  MN2 active session
MN1 gets “c”
DHCP server (or MN1) informs NAT
MN2 gets ICMP host unreachable
Starts sending to NAT
NAT responds router redirect “c”
MN1 moves out of domain
• Path MN1visited NAT home
NATMN2
(?) ICMP Redirect message is expected from router in the same sub-net to which
packet is being sent. It is vulnerable to attacks (confirm?) Cisco routers don’t forward
ICMP redirect from another network. We may use proprietary IP options if allowed.
13-Oct-03
MobileNAT/IRT group meeting
47
TODO

Can MobileNAT co-exist with MIP, Hawaii and non-mobile
but IP clients?
•
•
•
•
•
•
•
•
13-Oct-03
If MIP MN discovers no FA, switches to MobileNAT
If MobileNAT MN discovers FA, enables both MIP and MobileNAT
If MobileNAT MN goes out of domain and gets a public address
If a public MN moves within the domain and gets private address
For intra-domain session between MN and fixed IP host, route optimization
does not work
Does route optimization work if both MN move at the same time?
Does MobileNAT work with multicast?
Write a simulation program for MobileNAT, MobileIP and Hawaii network
MobileNAT/IRT group meeting
48
TODO

Can part of it be implemented using existing protocols like
Mobile IPv6 (destination option for route optimization),
IDMP (for public/private addresses), RSIP)?
• Intra-domain Route optimization is similar to IPv6 destination option; can
•
•
•
13-Oct-03
we use IPv6 within domain – need to change all routers (?)
Assuming IPv6 domain with NAT as IPv4IPv6 converter. What changes
we need in NAT/IOTA so that it works with Mobile IP? For IPv6 do we need
private address domain? How do we minimize changes in IPv6 MN?
IDMP supports multiple MA. Can we install multiple NAT/IOTA for load
balancing?
Does tunnel mode MobileNAT reduce to IDMP, when HA is outside of NAT
and FA is in MN? (yes) Why can’t MobileNAT be proposed as an extension
to IDMP? IDMP does not describe intra-domain session optimization.
MobileNAT/IRT group meeting
49
TODO

Windows related issues
• Check if TCP connections are dropped when ipconfig /release is done
• Check what happens when CONNECTED status is indicated on already
•

connected state
Check if TCP connections are dropped even if DISCONNECTED status is
not propagated to higher layer
Possible deployment hindrances
•
•
•
•
13-Oct-03
Changing every MN driver (similar to Mobile IP)
Should allow incremental deployment
Processing overhead on NAT/IOTA
What happens to domain/sub-net specific options that are not indicated to
the higher layer when domain/sub-net change? Need to write a controlling
application also that does DhcpIpRenewAddress when driver finds a
different options field.
MobileNAT/IRT group meeting
50
TODO

Basic design issues
•
•
•
•
•
Does DHCP security/authentication work?
Can we use ICMP router redirect from NAT to private host?
Can IP security work in all scenarios?
Fast handoff applicability
Since anyway we are modifying MN driver, can it be made more extensible
or more auto-configurable.
 E.g., if IOTA/NAT is moved to sub-net routers then can modification in MN be
avoided? What if multiple hierarchical IOTA/NAT in a domain?
13-Oct-03
MobileNAT/IRT group meeting
51