Interconnecting P2PSIP and IMS

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Interconnecting P2PSIP and IMS

• Jani Hautakorpi¹, Arturo Salinas¹, Erkki
  Harjula², Mika Ylianttila²
• ¹Ericsson Research Nomadiclab
• ²MediaTeam Oulu Group, University of Oulu
• NGMAST08
• 16-19th Sep 2008
• Cardiff, Wales, UK

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Content

• Motivation and background
• Interconnection architecture
• Overview
• Preliminary procedures
• Session establishment from P2PSIP to IMS
• Session establishment from IMS to P2PSIP
• Prototype
• Future work
• Conclusions

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Motivation and Background (1/3)

• Many ways to communicate
• Quite often no interconnection mechanisms
• This lead to separated islands

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Motivation and Background (2/3)
P2PSIP network
IMS network
AS
S-CSCF
SIP
HSS
P-CSCF
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Motivation and Background (3/3)

• Excluded topics
• IPv4/IPv6 interworking
• NAT traversal
• Media handling
• Charging

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Interconnection Architecture (1/6)Overview
P2PSIP network
IMS network
P2PSIP to IMS
IMS to P2PSIP
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Interconnection Architecture (2/6)Preliminary
Procedures

• Gateway AS registers itself to the P2PSIP network
• IMS users have to set up their iFCs
• P2PSIP users do not have any preliminary
  procedures

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Interconnection Architecture (3/6)Session
Establishment from P2PSIP to IMS (1/2)
P2PSIP UA (at p2p-domain.com)
Novel URI handling mechanism
SIP INVITE to user_at_ims-domain.com
Does the host name match my domain?
no
get
Get to H(ims-domain.com)
P2PSIP network
IPGW
yes
SIP INVITE to IPGW
INVITE
get
Get to H(user_at_ p2p-domain.com)
IPUSER
SIP INVITE to IPUSER
INVITE
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Interconnection Architecture (4/6)Session
Establishment from P2PSIP to IMS (2/2)
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Interconnection Architecture (5/6)Session
Establishment from IMS to P2PSIP (1/2)
SIP INVITE to user_at_p2p-domain.com
S-CSCF
Evaluate the trigger point in iFC Session
caseOriginating Request-URI_at_p2p-domain.com
IMS UA
P-CSCF
HSS
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Interconnection Architecture (6/6)Session
Establishment from IMS to P2PSIP (2/2)
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Prototype

• We implemented a prototype from the Gateway AS
• Used Open IMS Core
• Used Sofia-SIP
• Used SIPp
• Result Proposed architecture is valid

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Future Work

• Studies related to charging Probably different
  mechanisms for each direction
• Media handling Possibly a need for intermediary
  media elements
• IPv4/IPv6 interworking

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Conclusions

• We proposed an interconnection architecture
  between P2PSIP and IMS
• Contains novel URI handling mechanism
• Does not require changes to IMS terminals
• Prototype proves that the proposed architecture
  is valid