Cisco Cisco Packet Data Gateway (PDG)
SaMOG Gateway Overview
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SaMOG Administration Guide, StarOS Release 16 ▄
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Table 5. Attach Procedure Call Flow Descriptions
Step Description
1
UE associates with AP and WLC.
2
WLC starts EAP based authentication with UE and requests for the permanent identity of the user.
3
UE responds with the permanent identity (IMSI) stored on the SIM.
4
WLC requests SaMOG for authentication using Radius Access Request message.
5
SaMOG uses the STa interface towards 3GPP HSS to fetch subscriber authentication challenge. If LBO is enabled,
SaMOG forwards DER-Flags (in the DER msg) with "NSWO-Capability" bit set to '1' to indicate to AAA that it supports
LBO. Else, it sends the DER-Flags with "NSWO-Capability" bit set to '0'.
SaMOG forwards DER-Flags (in the DER msg) with "NSWO-Capability" bit set to '1' to indicate to AAA that it supports
LBO. Else, it sends the DER-Flags with "NSWO-Capability" bit set to '0'.
6
HSS returns the authentication parameters to SaMOG for the subscriber. The DEA message may contain DEA-Flags.
7
SaMOG sends Radius-Access-Challenge message to the WLC.
8
WLC in turn sends authentication challenge to UE.
9
UE responds with challenge response.
10
WLC initiates Radius Access Requests towards SaMOG with challenge response.
11
SaMOG originates STa AARequest towards HSS. If LBO is enabled, SaMOG sends DER-Flags (in the DER msg) with
"NSWO-Capability" bit set to '1' to indicate to AAA that it supports LBO. Else, it sends the DER-Flags with "NSWO-
Capability" bit set to '0'.
"NSWO-Capability" bit set to '1' to indicate to AAA that it supports LBO. Else, it sends the DER-Flags with "NSWO-
Capability" bit set to '0'.
12
HSS authenticates the subscriber and also returns the subscriber profile information to MRME. The profile information will
contain the Default QoS profile, Default APN, APN-AMBR, and Charging Characteristics.
contain the Default QoS profile, Default APN, APN-AMBR, and Charging Characteristics.
13
If the APN profile requires LBO for the APN, either of the following conditions is met:
DEA-Flags not received
DEA-Flags received with the “NSWO-Authorization” bit set to 1.
The P-GW service is then associated with the SaMOG service, and the associated P-GW IP address is used for LBO. Or, if
a static IP address is provided by AAA, the address is used for allocation.
If neither of the conditions above is met, DNS resolution is performed to determine the P-GW address.
a static IP address is provided by AAA, the address is used for allocation.
If neither of the conditions above is met, DNS resolution is performed to determine the P-GW address.
14
SaMOG sends Radius-Access-Accept message towards WLC with some of the information mentioned in Step12 (APN
Name, PDN-GW/LGW address).
Name, PDN-GW/LGW address).
15
EAP Success is sent to the UE.
16
For access-type EoGRE, UE sends DHCP Discover to SaMOG via. WLC.
For access-type PIMP, WLC originates the PMIPv6 Proxy-Binding-Update message to SaMOG with the information from
Step 13. Additionally, WLC allocates a GRE tunnel ID for downlink data transfer and includes it in PBU message.
For access-type PIMP, WLC originates the PMIPv6 Proxy-Binding-Update message to SaMOG with the information from
Step 13. Additionally, WLC allocates a GRE tunnel ID for downlink data transfer and includes it in PBU message.
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For access-type EoGRE, the IP address allocated in Step 13 via. the associated P-GW is sent in the DHCP Offer msg.
For access-type PIMPv6, the IP address allocated in Step 13 via. the associated P-GW is sent in the PBA message. The
SaMOG service will setup the GRE tunnel and include the GRE tunnel ID for uplink data transfer.
For access-type PIMPv6, the IP address allocated in Step 13 via. the associated P-GW is sent in the PBA message. The
SaMOG service will setup the GRE tunnel and include the GRE tunnel ID for uplink data transfer.
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For access-type EoGRE, the DHCP Request and DHCP Ack messages are forwarded to complete the IP address allocation.
For access-type PMIPv6, WLC acts as DHCP server to the UE, and assigns the IP address received in PBA.
For access-type PMIPv6, WLC acts as DHCP server to the UE, and assigns the IP address received in PBA.