Cisco Cisco ASR 5000
Direct Tunnelling for the S4-SGSN
How It Works ▀
SGSN Administration Guide, StarOS Release 18 ▄
Source RNC
DT Status
DT Status
Direct
Forwarding
Forwarding
S-GW
Relocation
Relocation
Behavior
Supported
No
Yes
Forward Relocation Request is sent with SGW S12 U FTEID. If peer is MME, IDFT
is applied. Then Create Indirect Data Forwarding Tunnel Request is sent with eNB
User plane FTEID received in the Forward Relocation Response. The SGW DL
forwarding user plane FTEID received in the Create Indirect Data Forwarding Tunnel
Response is sent in the Relocation Command.
is applied. Then Create Indirect Data Forwarding Tunnel Request is sent with eNB
User plane FTEID received in the Forward Relocation Response. The SGW DL
forwarding user plane FTEID received in the Create Indirect Data Forwarding Tunnel
Response is sent in the Relocation Command.
Supported
Yes
Yes
Forward Relocation Request is sent with SGW S12 U FTEID. The eNB / RNC use
plane FTEID received in the Forward Relocation Response is sent in the Relocation
Command.
plane FTEID received in the Forward Relocation Response is sent in the Relocation
Command.
Network Initiated Secondary PDP Context Activation
The S-GW sends a Create Bearer Request for Network Initiated Secondary PDP Context Activation with the SGW
S12U FTEID. This FTEID is sent in a RAB Assignment Request to the RNC. The RNC S12U FTEID received in the
RAB Assignment Response is sent to the S-GW in a Create Bearer Response.
S12U FTEID. This FTEID is sent in a RAB Assignment Request to the RNC. The RNC S12U FTEID received in the
RAB Assignment Response is sent to the S-GW in a Create Bearer Response.
Figure 41. Network Initiated Secondary PDP Context Activation
PGW Init Modification when UE is Idle
If UE is in IDLE state and PGW Init Modification is received, the SGSN sends the first MBR. Upon getting PGW Init
Modification in Idle State, the SGSN queues the PGW Init Modification and feeds a Downlink Data Notification
internally. This sets up all RABs (using old QoS) and sends a Modify Bearer Request. When the Downlink Data
Procedure is completed, the queued PGW Init Modification is processed.
Modification in Idle State, the SGSN queues the PGW Init Modification and feeds a Downlink Data Notification
internally. This sets up all RABs (using old QoS) and sends a Modify Bearer Request. When the Downlink Data
Procedure is completed, the queued PGW Init Modification is processed.