Mobile IPv4 Dynamic Home Agent
Assignment Framework
(draft-kulkarni-mobileip-dynamic-assignment-01.txt)
57th IETF Vienna – 7/14/2003
Milind Kulkarni
Alpesh Patel
Kent Leung
Presentation_ID
© 2001, Cisco Systems, Inc. All rights reserved.
1
Problem Statements
• Optimal Home Agent for geographically /
topologically distant locations
• Reduce configuration needs on Mobile
Nodes (HA not required)
• Allow network to select and
administratively assign HA to MN
• Load balance MNs among multiple HAs
2
Nearest HA Example
User moves to a distant location
3
Nearest HA Example
Latency increases for registrations
and tunneled traffic.
Printer
Home Agent
Mobile Node
4
Dynamic HA Assignment
Dynamically assigned HAs to
anchor mobility sessions initiated
Home Agent
within regions
Printer
Home Agent
Mobile Node
X
5
HA Assignment Methods
Dynamic HA Assignment Framework
• DHCP – Home Agent Option 68
• AAA – 3GPP2 IS-835
• DNS – Hostname resolution
• Static configuration
• Etc.
6
Terminology
• ALL-ZERO-ONE-ADDR (AZOA): IP address
0.0.0.0 or 255.255.255.255.
• Directed HA: Destination IP address of the
Registration Request to targeted Home Agent.
• Assigned HA: IP address in the Home Agent
field of an accepted Registration Reply. The
designated Home Agent for the duration of the
mobility session.
7
Dynamic HA Assignment Framework
Initial Registration Control Flow
D
S
Directed
COA
HA
or CCOA
RRQ
HA
AZOA
or HAA
Home Agent
…
Foreign Agent
COA
Router
D
COA
or CCOA
S
HA
RRP
HA
Assigned
HAA
…
CCOA
Mobile Node
8
Dynamic HA Assignment Framework
Re-registration Control Flow
D
S
Assigned
Directed
COA
HA
or CCOA
RRQ
HA
Assigned
HA
Home Agent
…
Foreign Agent
COA
Router
D
COA
or CCOA
S
HA
RRP
HA
Assigned
HAA
…
CCOA
Mobile Node
9
HA Redirection
Initial Registration Control Flow
D
S
Directed
COA
HA
or CCOA
RRQ
HA
AZOA
or HAA
…
Home
Agent
Foreign Agent
COA
Router
D
COA
or CCOA
S
HA
RRP
HA
Assigned
HAA
…
CCOA
Mobile Node
10
HA Redirection
Re-registration Control Flow
D
S
Assigned COA
HA
or CCOA
RRQ
HA
Assigned
HAA
…
Home
Agent
Foreign Agent
COA
Router
D
COA
or CCOA
S
HA
RRP
HA
Assigned
HAA
…
CCOA
Mobile Node
11
AZOA Application
• Mobile Node registers to Assigned HA for
duration of mobility session
• AZOA should be used to initiate a new
mobility session
Registration Requests
AZOA used
Assigned HA used
Time
12
Discussion Points
13
RFC 3344 Update
• The Home Agent MAY accept registration
with assigned HA address different than in
the registration request with unicast
destination IP address
14
Directed vs. Assigned
• Framework provides flexibility to allow
assigned HA to be same or different than
the target of registration requests
15
MN-HA Security Considerations
• MN – HA SA manually configured or
dynamic established, dependent on
method
• MN – HA SA may be per HA or per
administratively domain (for HAs within)
16
Q&A
17