PDN Gateway Overview
▀ Features and Functionality - Base Software
▄ Cisco ASR 5x00 Packet Data Network Gateway Administration Guide
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Important:
For more information on command line interface based management, refer to the
Command Line
Interface Reference
.
MPLS EXP Marking of User Plane Traffic
Similar to 802.1p marking, MPLS EXP bit marking is supported for Enterprise APN’s that use MPLS tunneling on the
SGi interface on the P-GW. The QoS marking used in the LTE/EPC network (QCI per EPS bearer) is mapped to the
802.1p and MPLS EXP bit marking between the P-GW and L2/EPC switch and MPLS/PE routers (this is applicable to
the upstream direction, from the P-GW to the Network).MPLS EXP marking related configuration is available as part of
the QCI-QOS configuration table. MPLS EXP marking is selected based on QCI of the bearer to which that packet
belongs.
Mobile IP Registration Revocation
Mobile IP registration revocation functionality provides the following benefits:
Timely release of Mobile IP resources at the HSGW and/or P-GW
Accurate accounting
Timely notification to mobile node of change in service
Registration Revocation is a general mechanism whereby either the P-GW or the HSGW providing Mobile IP
functionality to the same mobile node can notify the other mobility agent of the termination of a binding. Mobile IP
Registration Revocation can be triggered at the HSGW by any of the following:
Session terminated with mobile node for whatever reason
Session renegotiation
Administrative clearing of calls
Session Manager software task outage resulting in the loss of HSGW sessions (sessions that could not be
recovered)
Important:
Registration Revocation functionality is also supported for Proxy Mobile IP. However, only the P-
GW can initiate the revocation for Proxy-MIP calls.
Important:
For more information on MIP registration revocation support, refer to the
Mobile IP Registration
Revocation
appendix in this guide.
MTU Size PCO
UEs usually use a hardcoded MTU size for IP communication. If this hardcoded value is not in sync with the network
supported value, it can lead to unnecessary fragmentation of packets sent by the UE. Thus, in order to avoid unnecessary
fragmentation, this feature helps in using the network-provided MTU size instead of the hardcoded MTU in UE.
3GPP defined a new PCO option in Release 10 specifications for the network to be able to provide an IPv4 MTU size to
the UE. P-GW supports an option to configure a IPv4 Link MTU size in the APN profile.