Content for TR 29.809 Word version: 12.0.0
2 References
3 Definitions, symbols and abbreviations
4 Introduction
5 Impacts of Diameter Overload in 3GPP Networks
6 Requirements for Diameter Overload Control
7 Solutions for Diameter overload control
8 Conclusions and Recommendations
A PCRF Overload Impacts per Interface
$ Change History
2 References p. 7
3 Definitions, symbols and abbreviations p. 9
3.1 Definitions p. 9
3.2 Abbreviations p. 9
4 Introduction p. 9
5 Impacts of Diameter Overload in 3GPP Networks p. 9
5.1 Introduction p. 9
5.2 Diameter Overload p. 10
5.2.1 Introduction p. 10
5.2.2 Diameter Overload Problem p. 10
5.2.3 Limitations of Existing Mechanisms in Diameter p. 10
5.3 Overload Scenarios in 3GPP Networks p. 11
5.3.1 Introduction p. 11
5.3.2 Overload of the HSS p. 11
5.3.3 Overload of the PCRF/DRA p. 12
5.3.3.1 Introduction p. 12
5.3.3.2 Overload of the PCRF p. 12
5.3.3.3 Overload of the DRA used for the PCRF selection p. 14
5.3.4 Overload of the 3GPP AAA Server p. 15
5.3.5 Overload of the Offline Charging System (OFCS) p. 16
5.3.5.1 Introduction p. 16
5.3.5.2 Causes p. 16
5.3.5.2.1 Network Causes p. 16
5.3.5.2.2 Multiple Interfaces for the Same Bearer/Session/Service p. 17
5.3.5.2.4 Multiple Interfaces for the Same User p. 17
5.3.5.2.5 Tariff SwitchTime p. 17
5.3.5.2.6 Overload of the CTF p. 17
5.3.5.3 Impacts p. 17
5.3.6 Overload of the Online Charging System (OCS) p. 18
5.3.6.1 Introduction p. 18
5.3.6.2 Causes p. 19
5.3.6.2.1 Network causes p. 19
5.3.6.2.2 Multiple Interfaces for the Same Bearer/Session/Service p. 19
5.3.6.2.3 Multiple Interfaces for the Same User p. 19
5.3.6.2.4 Tariff SwitchTime p. 20
5.3.6.2.5 OCS Sy Application p. 20
5.3.6.2.6 Overload of the CTF p. 20
5.3.6.2.7 Simultaneous Online/Offline Sessions p. 20
6 Requirements for Diameter Overload Control p. 20
6.1 Introduction p. 20
6.2 Design Considerations p. 20
6.2.1 Introduction p. 20
6.2.2 Impacts on Existing Applications used in 3GPP p. 20
6.2.2.1 Introduction p. 20
6.2.2.2 Overload and Applications p. 20
6.2.2.3 Complexity p. 21
6.2.2.4 3GPP Diameter Charging Applications p. 21
6.2.3 Extensibility and Interoperability p. 23
6.2.3.1 General p. 23
6.2.4 Diameter Session Management in 3GPP networks p. 24
6.2.4.1 General p. 24
6.2.5 Network Architecture Considerations p. 25
6.2.5.1 Introduction p. 25
6.2.5.2 Network Topologies p. 25
6.2.5.2.1 Introduction p. 25
6.2.5.2.2 Types of Network Topologies p. 27
6.2.5.2.3 Network Topologies with HSS p. 28
6.2.5.2.4 Network Topologies with PCRF p. 29
6.2.5.3 Heterogeneous Networks p. 29
6.2.5.4 Interconnected Networks p. 30
6.2.6 Network Performances p. 30
6.3 Diameter Overload Prevention and Detection p. 30
6.3.1 Introduction p. 30
6.3.2 Explicit Overload Indication p. 30
6.3.2.1 Introduction p. 30
6.3.2.2 Overload information propagation p. 30
6.3.2.3 Overload status information to be carried p. 31
6.3.2.4 Transfer of Load/Overload Information p. 31
6.3.3 Implicit Overload Indication p. 31
6.3.3.1 Introduction p. 31
6.4 Diameter Node Behavior for Overload Mitigation p. 32
6.4.1 Introduction p. 32
6.4.2 Load-balancing p. 32
6.4.2.1 General p. 32
6.4.3 Message Retransmission p. 33
6.4.3.1 General p. 33
6.4.4 Message Throttling p. 33
6.4.4.1 General p. 33
6.4.4.2 Throttling by Throttling Factor p. 34
6.4.4.3 Throttling by maximum Rate p. 34
6.4.4.4 Throttling by window of unanswered messages p. 34
6.4.5 Message Prioritization p. 34
6.4.5.1 General p. 34
6.4.6 Application Prioritization p. 36
6.4.6.1 General p. 36
6.4.7 Overload Mitigation Differentiation per Client p. 36
6.4.7.1 General p. 36
6.4.8 Overload Information Aggregation p. 36
6.4.8.1 General p. 36
6.5 3GPP-IETF Requirements Gap Analysis p. 36
6.5.1 Introduction p. 36
6.5.2 General 3GPP requirements p. 37
6.5.2.1 General p. 37
6.5.3 Review of IETF Requirements p. 37
6.5.3.1 General p. 37
6.5.4 Conclusions p. 41
7 Solutions for Diameter overload control p. 41
7.1 Introduction p. 41
7.2 Solution 1: MDOC p. 41
7.2.1 Solution overview p. 41
7.3 Solution 2: DOCA p. 43
7.3.1 Solution Overview p. 43
7.4 Solution 3: OVLI p. 44
7.4.1 Solution overview p. 44
7.5 Comparison p. 45
7.6 Conclusions p. 48
8 Conclusions and Recommendations p. 49
8.1 Introduction p. 49
8.2 Solution for Diameter Overload Control in 3GPP Networks p. 49
8.3 Impacts on Existing 3GPP Specifications p. 49
8.3.1 Introduction p. 49
8.3.2 Considerations on existing 3GPP specifications p. 49
8.3.3 Impacts on the S6a/d interface p. 50
8.3.3.1 General p. 50
8.3.3.2 Mapping to NAS causes p. 50
8.4 Recommendations for New Diameter Applications p. 52
A PCRF Overload Impacts per Interface p. 53
A.1 Impacts due to the overload of the PCRF p. 53
A.1.1 Impacts when a DRA is not deployed p. 53
A.1.1.1 Impacts on the Gx interface p. 53
A.1.1.2 Impacts on the Gxx interface p. 54
A.1.1.3 Impacts on the Rx interface p. 55
A.1.1.4 Impacts on the S9 interface p. 55
A.1.1.4.1 Introduction p. 55
A.1.1.4.2 Overload of the H-PCRF p. 56
A.1.1.4.3 Overload of the V-PCRF p. 56
A.1.1.5 Impacts on the Sd interface p. 56
A.2 Impacts when a DRA is deployed p. 56
$ Change History p. 58
