A)
If Direct Tunnel was established the SGSN update these EPS Bearer contexts by sending Modify Bearer Request (SGSN Tunnel Endpoint Identifier for Control Plane, EPS Bearer ID(s), SGSN Address for Control Plane, SGSN Address(es) and TEID(s) (if Direct Tunnel is not used) or RNC Address(es) and TEID(s) for User Traffic (if Direct Tunnel is used), PDN-GW addresses and TEIDs (for GTP based S5/S8) or GRE keys (for PMIP based S5/S8) at the PDN-GW(s) for uplink traffic, serving network identity, CGI/SAI, RAT type, MS Info Change Reporting support indication, DTI). If Direct Tunnel is established the SGSN shall include the DTI to instruct the S-GW to apply Direct Tunnel specific error handling procedure as described in
clause 13.8. The SGSN puts the according NSAPI in the field of EPS Bearer ID.
B)
If MS Info Change Reporting is started, the S-GW sends Modify Bearer Request (EPS Bearer ID(s), serving network identity, CGI/SAI, RAT type, MS Info Change Reporting support indication) messages to the P-GWs involved.
C)
The P-GWs acknowledge with sending Modify Bearer Response (TEID, Prohibit Payload Compression, MS Info Change Reporting Action, CSG Information Reporting Action) messages to S-GW. The Prohibit Payload Compression indicates that the SGSN should negotiate no data compression for this EPS Bearer context.
D)
The Serving GW acknowledges the user plane switch to the SGSN via the message Modify Bearer Response (Cause, Serving GW Tunnel Endpoint Identifier for Control Plane, Serving GW Address for Control Plane, Protocol Configuration Options, PDN-GW addresses and TEIDs (for GTP based S5/S8) or GRE keys (for PMIP based S5/S8) at the PDN-GW(s) for uplink traffic, Prohibit Payload Compression, MS Info Change Reporting Action, CSG Information Reporting Action). At this stage the user plane path is established for all EPS Bearer contexts between the UE, target RNC, SGSN in case Direct Tunnel is not used, Serving GW and PDN-GW.
A)
The SGSN selects the new Serving GW as described in
clause 4.3.8.2 of TS 23.401 on
"Serving GW selection function", and sends a Create Session Request message (SGSN Tunnel Endpoint Identifier for Control Plane, EPS Bearer ID(s), SGSN Address for Control Plane, SGSN Address(es) and TEID(s) (if Direct Tunnel is not used) or RNC Address(es) and TEID(s) for User Traffic (if Direct Tunnel is used), PDN-GW addresses and TEIDs (for GTP based S5/S8) or GRE keys (for PMIP based S5/S8) at the PDN-GW(s) for uplink traffic, serving network identity, CGI/SAI, RAT type, MS Info Change Reporting support indication, DTI). If Direct Tunnel is established the SGSN shall include the DTI to instruct the S-GW to apply Direct Tunnel specific error handling procedure as described in
clause 13.8.
B)
The new S-GW sends Modify Bearer Request (EPS Bearer ID(s), serving network identity, CGI/SAI, RAT type, MS Info Change Reporting support indication) messages to the P-GWs involved.
C)
The P-GWs acknowledge with sending Modify Bearer Response (TEID, Prohibit Payload Compression, MS Info Change Reporting Action, CSG Information Reporting Action) messages to new S-GW. The Prohibit Payload Compression indicates that the SGSN should negotiate no data compression for this EPS Bearer context.
D)
The new Serving GW acknowledges the user plane switch to the SGSN via the message Create Session Response (Cause, Serving GW Tunnel Endpoint Identifier for Control Plane, Serving GW Address for Control Plane, Protocol Configuration Options, PDN-GW addresses and TEIDs (for GTP based S5/S8) or GRE keys (for PMIP based S5/S8) at the PDN-GW(s) for uplink traffic, Prohibit Payload Compression, MS Info Change Reporting Action, CSG Information Reporting Action). The SGSN starts timer, to be used in step F.
E)
The SGSN configures the necessary Iu resources for the Target RNC and responds with Enhanced Relocation Complete Response. The SGSN provides to the target RNC the new S-GW's Address for user Plane and TEID(s) for Uplink data. The target RNC starts using the new Serving GW address and TEID(s) for forwarding subsequent uplink packets.
F)
When the timer has expired after step D, the SGSN releases the bearer(s) in old S-GW by sending a Delete Session Request message.
G)
The old S-GW acknowledge bearer deletion.