Cisco Cisco ASR 5000
IP Services Gateway Overview
Enhanced Feature Support ▀
IPSG Administration Guide, StarOS Release 17 ▄
21
Step
Description
6—
10
10
Unauthenticated Phase: In the pre-auth stage, the applicable username and other attributes pertaining to the subscriber
are not available. The session creation request (Accounting-Start Req) at IPSG contains Username=UE IP (this should be
string type), Framed-IP-Address=UE IP, Calling-Station-Id="000000000000000", 3GPP-IMSI="000000000000000", SN-
Assigned-VLAN-ID=VlanId, Called-Station-Id="UnauthEud"; 3GPP-RAT-Type="UTRAN".
are not available. The session creation request (Accounting-Start Req) at IPSG contains Username=UE IP (this should be
string type), Framed-IP-Address=UE IP, Calling-Station-Id="000000000000000", 3GPP-IMSI="000000000000000", SN-
Assigned-VLAN-ID=VlanId, Called-Station-Id="UnauthEud"; 3GPP-RAT-Type="UTRAN".
12—
22
22
HTTP redirection occurs at IPSG.
23
The user between the ISG and CAR/SIS is authenticated using and user credentials like EndUserName, EndUserId used
for 3GPP-IMSI , Calling-Station-id, auth APN to be used etc are obtained.
for 3GPP-IMSI , Calling-Station-id, auth APN to be used etc are obtained.
24—
28
28
ISG/CAR send a new Accounting Start with the actual user credentials obtained from CAR/SIS subsystems. The same IP
address and VLAN ID used during the un-phase is used again. The Username, Calling-Station-Id and APN are updated to
reflect the actual user credentials. The replacement feature at IPSG based on diff-key is enabled at IPSG so the new
session request replaces the earlier one for the same IP and VLAN-ID. Otherwise, ISG/CAR sends an Accounting-Stop
for the previous session created for the un-authenticated user before sending the Accounting-Start for the authenticated
user.
address and VLAN ID used during the un-phase is used again. The Username, Calling-Station-Id and APN are updated to
reflect the actual user credentials. The replacement feature at IPSG based on diff-key is enabled at IPSG so the new
session request replaces the earlier one for the same IP and VLAN-ID. Otherwise, ISG/CAR sends an Accounting-Stop
for the previous session created for the un-authenticated user before sending the Accounting-Start for the authenticated
user.
29
The uplink and downlink data call flow is same as steps 12-22, where the VLAN tagged data on the Sn interface is
mapped to the MPLS tagged data on the Si side and vice-versa.
mapped to the MPLS tagged data on the Si side and vice-versa.
Dictionary Requirements
This section provides AVP requirements for the overlapping IP support over VLAN feature.
The following are the AVPs required, based on dictionaries starent-vsa1 or custom54
AVP
STARENT-
VSA1
VSA1
CUSTOM54 Additional Information
Acct-Status-Type
Mandatory
Mandatory —
User-Name
Mandatory
Optional
For custom54, if present, this AVP is used. Otherwise, a default value
“void” is used as the username in ipsgmgr.
“void” is used as the username in ipsgmgr.
Calling-Station-Id
Optional
Mandatory For starent-vsa1, this AVP will be set to null and processed in ipsgmgr.
Framed-Ip-Address
Mandatory
Mandatory Optional if an IPv6 prefix exists.
Optional for Radio Access requests.
Acct-Session-Id
Mandatory
Mandatory Optional for Radio Access requests.
Called-Station-Id
Mandatory
Mandatory Optional for Subscriber profile and Radio Access requests.
SN-Assigned-
VLAN-ID
VLAN-ID
Mandatory
Mandatory This AVP is used to forward the VLAN ID.
SN-Transparent-
Data
Data
Optional
Optional
—
SN-Vpn-Name
Mandatory
Mandatory This AVP is used to forward the VPN name (destination context).