Cisco Cisco ASR 5000
Direct Tunnelling for the S4-SGSN
How It Works ▀
SGSN Administration Guide, StarOS Release 18 ▄
Old RNC DT
Status
Status
New RNC
DT Status
DT Status
S-GW
Relocation
Relocation
Behavior
Not
Supported
Supported
Supported
Yes
Create Session Request to new S-GW is sent with DTF flag set and no user plane
FTEID. Even if S-GW sent S4U FTEID in CSR Response SGSN internally treats that
as an S12U FTEID and continues the relocation. Relocation Request to Target RNC is
sent with S12 U FTEID received in Create Session Response. Modify Bearer Request
to new S-GW is sent with RNC S12U FTEID
FTEID. Even if S-GW sent S4U FTEID in CSR Response SGSN internally treats that
as an S12U FTEID and continues the relocation. Relocation Request to Target RNC is
sent with S12 U FTEID received in Create Session Response. Modify Bearer Request
to new S-GW is sent with RNC S12U FTEID
Supported
Not
Supported
Supported
Yes
Create Session Request to new SGW is sent with S4 U FTEID. Relocation Request to
Target RNC is sent with SGSN U FTEID.Modify Bearer Request is sent with SGSN
S4U FTEID.
Target RNC is sent with SGSN U FTEID.Modify Bearer Request is sent with SGSN
S4U FTEID.
Supported
Supported
Yes
SGSN sends a Create Session Request to new SGW with DTF flag set and no user
plane FTEID.Even if S-GW sent S4U FTEID in CSR Response, SGSN will internally
treat that as S12U FTEID and continue the relocation. Relocation Request to the
Target RNC is sent with the S12 U FTEID received in the Create Session Response.
Modify Bearer Request to new S-GW is sent with RNC U FTEID.
plane FTEID.Even if S-GW sent S4U FTEID in CSR Response, SGSN will internally
treat that as S12U FTEID and continue the relocation. Relocation Request to the
Target RNC is sent with the S12 U FTEID received in the Create Session Response.
Modify Bearer Request to new S-GW is sent with RNC U FTEID.
New SRNS with S-GW Change and Direct Data Transfer
The new SGSN sends a Create Session Request with DTF flag set and no user plane FTEID to the new S-GW. The new
SGSN sends the SGW S12U FTEID received in the Create Session Response in Relocation Request to the Target RNC.
The new SGSN sends the RNC S12U FTEID received in a Relocation Request Ack to the new S-GW in a Modify
Bearer Request.
SGSN sends the SGW S12U FTEID received in the Create Session Response in Relocation Request to the Target RNC.
The new SGSN sends the RNC S12U FTEID received in a Relocation Request Ack to the new S-GW in a Modify
Bearer Request.