Transcript Transport of MIH Messages Over IP

Transport of Media
Independent HO
Messages over IP
68th IETF
MIPSHOP WG
draft-rahman-mipshop-mih-transport-02.txt
Akbar Rahman
Ulises Olvera-Hernandez
Mahmoud Wafta
Juan Carlos Zuniga
Hyun-Wook Kim
([email protected])
([email protected])
([email protected])
([email protected])
([email protected])
802.21 Concepts

MIH uses a Common Header for Information,
Command, and Event services (i.e. IS, CS, & ES)
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MIH protocol provides the following Identifiers:
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No need to define headers for each of IS, CS, or ES
MIHF ID: uniquely defines MIHF endpoints
Transaction ID: an identifier used with every MIH request and
its response message
MIH messages provide ACK bits for optional reliability
MIH Message Multiplexing
MIH User 1
e.g. MIP
MIH User 2
e.g. SIP
MIH multiplexing
taken care of by
the MIH
application layer
MIH Function
Transport e.g.
UDP, TCP
Transport
multiplexing taken
care of by IP
MIH
Transport
IP
IP
Internet
MIH
Transport
IP
Network Model
Mobility Manager (MM)
2. An MIH application
enabled node
providing IS, CS and
ES for HO support
Internet
Cellular
network
Signalling
over IP
WLAN
network
Signalling
over IP
WiMax
network
MIH
Proxy
WLAN AP
Cellular
BS
1. MIH-capable mobile
node (MN)
communicating with
MM over IP
WiMax BS
L2
Signalling
MN
Proposal

The main objective is to keep the implementation of MIH transport as
light as possible in both MN and MM

MN discovers MM at initialization

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Use UDP as a transport mechanism for MIH messages
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Use Hard-coding, or
DHCP for discovery as per draft-daniel-dhc-mihis-opt-02.txt
Fast, simple and easy to use
Used by many other control protocols
Rely on existing MIH functionalities

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Common MIH header for IS, CS, & ES
Discovery capabilities of MIH peers, e.g. Mobility Manager (MM)
MIH ACK bits for optional reliability

Use IPsec for secure message transport

In the unlikely case of a large MIH message, use IP Fragmentation
MIH Message Transfer
MIH Message
Sending…
UDP datagram
MIH
App.
Other
App.
UDP Transport
IP layer
Receiving…
IP packet
MIH App. uses a unique
port number that is
registered and obtained
through IANA
MIH Signaling: Directly Over UDP/IP
Mobile Node
Cellular
WLAN
Mobility Manager
Power up: connect to WLAN
1
Obtain Neighbor List
(after discovery and registration)
2
Send a request for IS (e.g. NL) and set application timer T1
ACK not received
timeout after T1
3
4
5
Retransmit request for IS and re-set application timer T1
Send IS response (with piggy backed ACK) and set application timer T1
Send ACK
MN then decides to
move to cellular
(based on radio conditions)
6
7
Send ‘Link Up’ ES to inform about HO completion (no ACK required)
Session continues
over cellular
Fragmentation, NAT Traversal, and
Security

Trend in IEEE 802.21 is to use small MIH messages
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NAT Traversal
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ES and CS: small and will not require fragmentation
IS could be large: use IP fragmentation when needed together with
retransmission timers for reliability
NAT traversal does not pose a problem in a typical operator
deployment scenario, since MN is behind a NAT and MM is not
Event reports can be setup in the MIH Function to perform keepalive functions and maintain the NAT binding
Security
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Use existing IPsec ESP or AH for secure MIH messaging
Use IPsec ESP with UDP encapsulation if MN is behind NATs
Summary
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Use UDP as a transport mechanism
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Simple, easy and well known behaviour
Fast transport for MIH messages
Re-use existing MIH protocol functions as much
as possible and define new functionalities only if
needed
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Use MIH ACK bits and retransmission timers to ensure
reliability whenever required
Use periodic Event reports for keeping NAT binding
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Light implementation of MIH Transport over IP
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Use IPsec and IP Fragmentation