Cisco Cisco Packet Data Gateway (PDG)
SaMOG Gateway Overview
Features and Functionality - License Enhanced Feature Software ▀
SaMOG Administration Guide, StarOS Release 17 ▄
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The DIAMETER AAA server sends the APN information in the APN-Configuration AVP in DEA. This AVP
may however be absent in case the AAA server authorizes only LBO, to indicate that any APN can be used for
LBO for the subscriber.
LBO for the subscriber.
The operator can configure "local-offload" for each APN supporting LBO under the APN profile. However, the
authorization from the AAA server will always be given preference over the local configuration. Local
configuration will be used to take a decision when AAA server authorizes GTP as well as LBO for a call.
configuration will be used to take a decision when AAA server authorizes GTP as well as LBO for a call.
The following table indicates different scenarios where the occurance of LBO is determined:
AAA Indication
APN
Received
Received
Matching APN with LBO in the
Local Configuration
Local Configuration
LBO/GTP Call Decision
Both GTP and LBO
NOT supported
NOT supported
—
—
Always an error condition
Only GTP Supported
No
—
Error Condition
Yes
—
GTP Call setup with GGSN/P-GW
Only LBO Supported
No
Yes
LBO session established with the first APN with
“local-offload” configured in local policy.
“local-offload” configured in local policy.
No
No APN configured in local
policy
policy
Error Condition
Yes
No
Error Condition
Yes
Yes
LBO session established with received APN.
Both GTP and LBO
Supported
Supported
No
—
Error Condition
Yes
No
GTP session established with received APN.
Yes
Yes
LBO session established with received APN.
Prepaid LBO Support
The SaMOG Gateway also supports Local Breakout (LBO) that enables time- and quota-based control to support
prepaid subscribers. SaMOG interfaces with the Enhanced Charging Services (ECS) using the Gy interface for prepaid
subscribers, and AAA for voucher-based subscribers. LBO for prepaid subscribers is supported on both PMIPv6 and
EoGRE access types.
prepaid subscribers. SaMOG interfaces with the Enhanced Charging Services (ECS) using the Gy interface for prepaid
subscribers, and AAA for voucher-based subscribers. LBO for prepaid subscribers is supported on both PMIPv6 and
EoGRE access types.
When a GTP session with the local P-GW or GGSN is set up, the local P-GW or GGSN service communicates with
ECS to obtain the time and quota limits of the subscriber by having the Gy interface forward the CCR-I message to the
Diameter Credit Control Application (DCCA) server to establish connection. Until the time or volume quota is reached,
the local P-GW or GGSN forwards the CCR-U message to DCCA in order to refresh the permitted time or volume
quota allowed. When the UE terminates the session, the internal P-GW forwards the final service usage to ECS, and
SaMOG completes the session.
ECS to obtain the time and quota limits of the subscriber by having the Gy interface forward the CCR-I message to the
Diameter Credit Control Application (DCCA) server to establish connection. Until the time or volume quota is reached,
the local P-GW or GGSN forwards the CCR-U message to DCCA in order to refresh the permitted time or volume
quota allowed. When the UE terminates the session, the internal P-GW forwards the final service usage to ECS, and
SaMOG completes the session.