Transcript mipshop

Mipshop – MIH DT report
IETF 69 – Chicago 24th July 2007
Admin stuff
• Updated DT members list:
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Subir Das
Nada Golmie
Heejin Jang
Telemaco Melia (editor and DT leader)
Sam Xia
Juan Carlos Zuniga
Gabor Bajko
• Document being worked out, available soon
• 802.21 liaison has been updated
Introduction
• The MIH L3 transport problem can be divided in
two parts
– Discovery
• Process required for the MIHF at the Mobile Node (MN) to
discover the peer MIHF (e.g. IP address) of the Mobility
Services (MoS) in the network, e.g. PoS (Point of Service),
either during initial attachment or during handover
– Transport
• This is the service provided to allow the communication
between two MIHFs via MIH protocol once they discover each
other
• Security aspects are considered together with the Transport
service
• Candidate solutions for both aspects have been
evaluated
– Existing standard track IETF-based solutions have
been given preference
Assumptions
• Solution is aimed at supporting 802.21 MIH
Services
• If MIHFID is available, FQDN or NAI’s realm is
used for MoS discovery
– DT recommends to 802.21 to restrict to only these two
• Solutions are chosen to cover all possible
deployment scenarios
– Next slide
• MIHF discovery can be executed during initial
network attachment or thereafter
Deployment Scenarios
• The following deployment scenarios are
identified
– Case 1: Home Network MoS
• The MN and the services are located in the Home Network
(MoSh)
– Case 2: Visited Network MoS
• MN is in the Visited Network and services are also provided
by the Visited Network (MoSv)
– Case 3: Roaming MoS
• MN is in the Visited Network and all services are provided by
the Home Network (MoSh)
– Case 4: MoS3
• MN is in Home or Visited Network and services are provided
by a 3rd Party Network (MoS3)
Discovery (1/2)
• From the different considered solutions, DHCP and DNS
are the two main options
• DHCP
– Works for deployment cases 1 and 2, either
• Providing directly the IP address of the MIHF, or
• Providing MoS domain name of serving network
– Then resolve the IP address of the peer MIHF by DNS
– Deployment case 3 can work if
• Relay configuration by AAA is used to discover the MoSh
– This requires tight coupling between Discovery and Network Access
Authentication
– Case 4 cannot be supported by DHCP
• Solution requires:
– Defining DHCPv4 and DHCPv6 options for MIH discovery and
– Registering DHCP Option codes with IANA
Discovery (2/2)
• DNS
– All deployment scenarios can be supported
• Visited network domain name can be obtained from DHCP
• Home network domain name can be preconfigured in MN
• Third party domain names can be obtained from an already
discovered MIH IS or others
– DNS resolution can be performed
• From the Service tag and then from the FQDN
– Solution requires:
• Defining DNS usage and service tag(s)
– e.g. “_mih._udp.mydomain.foo”
• Registering application service tag(s) “MIH” with IANA
Discovery (MN view example)
Legend:
DHCP: Use DHCP MIH option after
network acc auth
DHCP_AAA: Use DHCP MIH options
(tight coupling with AAA)
MN
discovering MoS
MoS address
preconf?
Y
end
N
DNS: Use DNS NAPTR/SRV
record query
N
Y
N
MoS in
visited network?
Y
DHCP/DNS
end
MN in Home
ntwk?
N
Y
Y
MoS in
Home network?
N
MoS in
Home network
DHCP_AAA/DNS
end
DNS
end
DHCP/DNS
end
Transport
• From the different considered solutions, UDP and TCP are
the two main options
– Both are applicable to all scenarios
– NAT/FW-traversal recommendations can be made
• MIH over UDP allows reliability via MIH ACK mechanism
defined in 802.21 and provides better latency
• MIH over TCP can provide additional congestion control
• Security can be provided at MIH level or by existing
transport/IP security mechanisms (e.g. IPsec, DTLS/TLS)
• Both UDP and TCP can be supported
– The choice would depend on latency and congestion control
requirements
• Solution requires:
– Writing definition (recommendations)
– Requesting Port # to IANA