Packet Data Architecture

1
Packet Data Architecture

• Boston PSAWG Working Session
• Frédéric ROSIN/Jackson CHAN - 11/07/2006

2
Outline

• Introduction
• Addressing Principle
• SNCDP context activation
• SNDCP context recovery process

3
Outline

• Introduction
• Addressing Principles
• SNDCP Context Activation
• SNDCP Context Recovery Process

4
Introduction

• Intent of the presentation
• Summary of discussions about addressing
• Clarify proposal with regard to SNDCP context and
  buffer recovery in case of roaming

5
Outline

• Introduction
• Addressing Principles
• SNDCP Context Activation
• SNDCP Context Recovery Process

6
Addressing principlesIP address assignment
methods

• Upon the first SNDCP context activation, an IP
  address is bound with the PDP context
• Static IP address assignment
• IP address is provided by the SNDCP CRA
• IP address shall be propagated to the Home RFSS
  in order to enable a consistency check between
  what is provisioned at the Home RFSS and what has
  been provisioned at the MRC.
• Dynamic IP address assignment
• SNDCP CRA conveys a DHCP request
• SNDCP CRA does not convey a DHCP request

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Addressing principlesIP address assignment

• Dynamic IP address assignment
• If a DHCP request is there, it is transparently
  conveyed to the Home RFSS using a specific SIP
  Register
• The Home RFSS performs the DHCP transaction with
  the DHCP server and sends back to the serving
  RFSS both the DHCP response and the IP address
  to be assigned
• Otherwise
• The Home RFSS assigns an IP address that should
  be always the same for the MRC itself and that is
  arbitrarily chosen for the MDP (No identification
  for the MDPs)
• Suggest to mandate that for a particular NSAPI
  value related to an SUID, the Home RFSS shall
  always assign the same IP address.

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Addressing principlesAPN

• Use of the APN to route IP packets received from
  the P25 mobile to a particular domain
• APN received upon SNDCP CRA is propagated to the
  Home RFSS using the specific register method.
• The Home RFSS is responsible for APN resolution
  and forward packets received from the serviced IP
  address to the edge router

DNS Look up (APN, IP address of the edge router)
SNDCP CRA (APN)
SIP register (APN)
Serving RFSS
Home RFSS
Edge router
IP packets received on the PDP context
APN Domain
9
Outline

• Introduction
• Addressing Principles
• SNDCP Context Activation
• SNDCP Context Recovery Process

10
SNDCP Context Activation
Home RFSS
Serving RFSS
MRC
U_REG_REQ
SIP Register (SU registration)
ACK_RSP_FNE
SIP 200 OK (SU registration)
U_REG_RSP
....
SNDCP CRA
SIP Register (SNDCP parameters )
SIP 200 OK (SNDCP parameters)
MIP Registration Request
MIP Registration Reply
SNDCP CAA
11
Outline

• Introduction
• Addressing Principles
• SNDCP Context Activation
• SNDCP Context Recovery Process

12
SNDCP Context Recovery
MIP Sessions shall be closed
Serving RFSS
Home RFSS
MRC
Old Serving RFSS
LOC_REG_REQ
SIP Register (SU reg.)
SIP Register (SU roamed New serving RFSS IP
address)
ACK_RSP_FNE
SIP 200 OK (SU roamed, SNDCP contexts)
SIP 200 OK (SU reg., SNDCP contexts)
LOC_REG_RSP
....
IP packet Outbound IP packet to be send on SNDCP
contexts
Timer
MIP Registration Request
MIP Registration Reply
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SNDCP Context RecoveryIP Packet data
Time
IP Packet forwarded by the Home
Old Serving Point
New Serving Point
MRC
Roaming Period