• Multi-Processor WAN Application Module Card on Cisco 7600 Internet Router and Catalyst 6500 platforms and in future it will be supported on Cisco 7206VXR/NPE-400 Platform with 512MB memory
Figure 1. Migration Diagram
Features in Cisco IOS Release 12.3(8)XU
Table 1. Cisco IOS Release 12.3(8)XU Features:
*VRF functionality, Overlapping IP Address and Tunnel support will be per image on the MWAM. VRF and Tunnel Aggregation at the SUP level will be supported in SUP720 in Tetons release.
- Local/Tertiary Charging GW support: This is to support a third CGW in addition to the two (primary and secondary) that Cisco GGSN already supports. The third CGW can be deployed locally so that if the access to the primary and secondary CGW which are remote fails, then the GGSN can as backup, send the CDRs to the local (third) CGW till one of both of the remote CGWs become operational. Then the GGSN switches back to the primary and/or secondary.
- Time Based Triggers: GGSN 5.0 needs to support time based triggers for generation of G-CDRs in addition to the volume based triggers that are already supported by the Cisco GGSN. These should be able to be enabled per GGSN or APN or per PDP context.
- Enabling Charging per APN: GGSN 5.0 should allow enabling/ disabling of generation of CDRs per APN.
Configurable Radius Attribute for Backward Compatibility: GGSN needs to allow configuration of the RADIUS attributes for MSISDN and the Account Session ID for a user to be able to support backward compatibility with WAP.
APN Based Features
- Mapping Multiple APNs to a Single VRF: GGSN 5.0 needs to support more than one APN per VRF. The maximum number of APNs per VRF need to be clearly documented in the SFS and the product bulletin and other customer documentation.
- Enabling Charging per APN: GGSN 5.0 should allow enabling/ disabling of generation of CDRs per APN. This is the same feature which is part of the Charging enhancements.
- Rate Limit for users per APN: This feature should allow a controlled distribution of bandwidth per APN. Some APNs may be recognized as those used for bandwidth intensive applications such as music mp3 hosts or others where image files or large file sizes are involved. The GGSN is configurable on a per APN basis to restrict the transfer rate per subscriber to an operator defined limit that would reduce the chance of a GGSN from being congested and thereby increase its availability. This is also part of the CAC and per PDP policing feature suite.
Support of Multiple Trusted PLMN IDs: Access to certain partner roaming MSs should be allowed and by default other roamers should be blocked on an APN basis. This allows the operators to provision access based on partner agreements. GGSN needs to allow more than one trusted PLMN Id. This is for operators forming multiple alliances and they do not want the MSs from their partners to be blocked because they do not belong to the home PLMN that the GGSN belongs to. This feature should allow the operator to configure multiple trusted MCC/MNCs.
- Maintenance Mode: GGSN needs to allow key APN configuration when there are active PDP contexts. GGSN should allow the operators to change the APN configuration in real-time, without tearing down any active PDP contexts on that APN. Example: This is a big issue for VF, Spain, for Parking meters where new PDP requests keep coming in even as the old ones are being torn down for maintenance purposes. They have 400 parking machines that use an APN, to change the APN, they must delete all PDP contexts, but as soon as they delete them the machines restart the PDP contexts, so there is a very short time they can change the APN, they end up having to unplug the cable or reboot, which is equivalent to loss of revenue.
- Prevent Generation of CDRs for active PDP contexts: This was a request from Amena, Spain. Deactivation of generation of G-CDRs for an active PDP context. Customers should be able to stop generation of G-CDRs when a PDP context is active without tearing down the PDP context to be able to do this. This is related to the above maintenance mode feature for allowing key APN configuration for active PDP contexts.
- UMTS CAC: UMTS Call Admission Control is used by the GGSN admission decisions based on the network resource availability and the policy set by the PDF in case of IMS subsystem implementation. It can also downgrade a service if the policy parameters from PDF do not match those from the SGSN. CAC is based on the parameters configured in the APN, such as max activated PDP, max bitrate, guaranteed bitrate, etc., and bandwidth allocated to a particular traffic class the PDP belongs to.
- Per PDP Policing: GGSN will support Per-PDP policing to limit downlink traffic at Gi interface. If the bandwidth is exceeded on a PDP context, packets may be dropped or assigned a higher drop precedence value.
- Rate Limit for PDPs per APN: GGSN 5.0 should allow operators to configure rate (bandwidth) thresholds per APN. This is also mentioned above in the APN Based Features.
L2TP Extension on Gi for PPP PDP Type
PPP PDP Type terminated in GGSN
QoS Mapping per standards for GTPv0
Duplicate IP Address Protection (also known as PLMN Address Protection)
Dynamic Echo Timer
In the previous releases, the retransmission scheme used for the GTP Echo messages is using the usual T3-timer and N3-Request. However according to the standard if a path failure is detected (i.e. no Echo Response after N3 Echo Request) on the Echo Request message, all PDP context related to this path shall be deleted. This feature allows the GGSN to use a dynamic timer for the Echo Request message. To avoid having a large number of PDP contexts to be deleted because of a network congestion between the GSNs, the dynamic echo timer takes into account the Round Trip Time (RTT) between GSNs.
PPP Regeneration (L2TP on Gi)
Virtual APN Support
Enhanced Security Feature Support
• Source IP spoofing protection (also called Anti-spoofing feature): This feature allows the operator to prevent source IP address spoofing and protects the network from malicious attacks by unauthorized users.
• PLMN Network Protection from MSs: This feature allows the operator to protect their PLMN by dis-allowing MS traffic to the destination IP address range that falls within or coincides with the PLMN's IP address range.
• Steer MS to MS traffic: This feature allows steering of MS to MS traffic to a specific external network element instead of allowing the traffic to loop through the GGSN. This is for firewall filtering and to enable external billing.
VRF Based VPN Switching
• Security (traffic separation and isolation)
• Reliability and Scalability (multiple interfaces can be supported in one VRF)
• Flexibility (can use policy and address space independently)
Charging for Roamers
GTP SLB Support for GTPv0 and GTPv1
GTP SLB for MWAM Based GGSNs:
Network Initiated PDP Context Support
• Complete 3GPP attribute support as per 29.061 specification
• Per PDP Accounting for GTPv1 sessions including accounting for Secondary PDPs
• Suppression of Radius attributes
• Support Anonymous access
• Support of VRF aware Radius groups
• RADIUS Class Attribute
• Session idle timer (on top of session idle timer per APN)
• Wait Accounting
Support anonymous access
RADIUS Class Attribute
Session Idle Timeout Timer ( configurable per APN)
• per session based on RADIUS attribute
• configurable, per APN
• configurable, per GGSN
Table 2. MWAM Cisco IOS Release 12.3(8)XU Feature Sets, Images and Descriptions: