Cisco Cisco IOS Software Release 12.4(22)XR
156
Cisco Packet Data Serving Node Release 5.0 for Cisco IOS Release 12.4(22)XR
OL-19026-01
Protocol Layering and RP Connections
handoff, the mobile station may connect the PDSN through another Base Station/PCF entity resulting in
establishment of another R-P connection between the PDSN and the new Base Station/PCF. This results
in the release of the R-P connection between the PDSN and the old Base Station/PCF.
establishment of another R-P connection between the PDSN and the new Base Station/PCF. This results
in the release of the R-P connection between the PDSN and the old Base Station/PCF.
R-P connection state information is maintained at the PDSN even during the dormant phase of the
session. When a mobile station transitions to active state, this information allows the PDSN to associate
the mobile station with an already available PPP connection. Loss of R-P state information results in the
release of the PPP connection by the PDSN. As a result, a mobile station accessing packet data services
following the loss of an R-P connection results in the establishment of a new PPP connection, and the
reset and restart of user applications. Therefore, the PDSN retains the R-P connection state information
to ensure minimal disruption of user applications during transitions between active and dormant session
phases.
session. When a mobile station transitions to active state, this information allows the PDSN to associate
the mobile station with an already available PPP connection. Loss of R-P state information results in the
release of the PPP connection by the PDSN. As a result, a mobile station accessing packet data services
following the loss of an R-P connection results in the establishment of a new PPP connection, and the
reset and restart of user applications. Therefore, the PDSN retains the R-P connection state information
to ensure minimal disruption of user applications during transitions between active and dormant session
phases.
PPP Connections
A PPP connection represents the link layer connectivity between the mobile station and the PDSN. It
includes the HDLC state, negotiated LCP parameters, negotiated IP address and CCP compression state
tables, and so on. Peer PPP entities may re-negotiate LCP and CCP parameters during an active session
without compromising continuity of user sessions; however, user identity, authentication-related
information and negotiated IP addresses are retained, thus ensuring that applications established over the
SimpleIP flow are unaware that renegotiation has occurred. PPP connection state information is retained
at the PDSN during dormant phase of the session to ensure minimal disruption of user applications
during transitions between active and dormant session phases.
includes the HDLC state, negotiated LCP parameters, negotiated IP address and CCP compression state
tables, and so on. Peer PPP entities may re-negotiate LCP and CCP parameters during an active session
without compromising continuity of user sessions; however, user identity, authentication-related
information and negotiated IP addresses are retained, thus ensuring that applications established over the
SimpleIP flow are unaware that renegotiation has occurred. PPP connection state information is retained
at the PDSN during dormant phase of the session to ensure minimal disruption of user applications
during transitions between active and dormant session phases.
Application Flows
One SIP and several MIP flow instances can be supported over a single PPP connection. For each SIP
flow, the state information includes the associated IP address, NAI and billing related user data records
(UDRs), and other related information. For each MIP flow, the state information includes the MIP visitor
list information, NAI and UDRs, and other related information.
flow, the state information includes the associated IP address, NAI and billing related user data records
(UDRs), and other related information. For each MIP flow, the state information includes the MIP visitor
list information, NAI and UDRs, and other related information.
PPPoGRE RP Interface
The PDSN interfaces with the Radio Network/Base Station to provide a transmission path for the user
data stream between the packet network and the radio access network. The PDSN interfaces to the Radio
Network through the Packet Control Function (PCF) using the PPPoGRE RP interface.
data stream between the packet network and the radio access network. The PDSN interfaces to the Radio
Network through the Packet Control Function (PCF) using the PPPoGRE RP interface.
The following list describes the transmission path between the Radio Network and the PDSN:
•
The PDSN provides a media-independent physical link that supports IP packet transport
capabilities.
capabilities.
•
The PPPoGRE RP Interface supports both the signaling channel and the bearer data transport
capabilities.
capabilities.
The PPPoGRE RP interface is based on 3GPP2 TIA/EIA/IS-835 standard for the control and bearer data
transport capabilities. The following list describes the differences between the 3GPP2 standard and
PPPoGRE RP Interface from the PDSN perspective:
transport capabilities. The following list describes the differences between the 3GPP2 standard and
PPPoGRE RP Interface from the PDSN perspective:
•
The PCF connecting the PDSN that supports PPPoGRE functionality sends the A11 Registration
request with the GRE Protocol Type field set to 0x880B.
request with the GRE Protocol Type field set to 0x880B.