Software Defined Network Architectures for Wireless Networks

Transcription

1 Software Defined Network Architectures for Wireless Networks Krishna M. Sivalingam Professor, Department of CSE, IIT Madras, Chennai , India Partly Supported by DST-EPSRC India-UK Advanced Technology Centre of Excellence in Next Generation Networks, Systems and Services (IU-ATC) May 22, 2015 Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

2 Acknowledgments 1 DST-EPSRC funded IU-ATC project ( ) 2 M.S. Students: P. R. Dhathri, Sakshi Chourasia 3 M. Tech. Student: Aditya Hegde 4 Ph.D. Students: Arkadeep Sen, C. S. Ganesh 5 Post-doctoral Associate: Dr. C. Vanniarajan Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

3 Overview Introduction to Software Defined Networks LTE-WiFi Seamless Mobility Architecture SDN based EPC Architecture SDN based WiFi Architecture

4 Motivation Mobile Data Traffic Explosion Exploding growth of mobile network traffic Cisco Visual Network Index (VNI), Feb reports: Tenfold increase in global mobile data from 2014 to Smartphone traffic will be 75% of mobile data traffic by G traffic will be 50% of mobile traffic by Limited availability of wireless spectrum is challenge Approaches studied: Focus on LTE and WiFi SDN Based EPC: Reduce signaling costs in network SDN for WiFi offloading: Cost-effective, easily deployable, highly available SDN based Entreprise WiFi: Improved Control and Customization, Seamless Inter-AP handover Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

5 Motivation Mobile Data Traffic Explosion Exploding growth of mobile network traffic Cisco Visual Network Index (VNI), Feb reports: Tenfold increase in global mobile data from 2014 to Smartphone traffic will be 75% of mobile data traffic by G traffic will be 50% of mobile traffic by Limited availability of wireless spectrum is challenge Approaches studied: Focus on LTE and WiFi SDN Based EPC: Reduce signaling costs in network SDN for WiFi offloading: Cost-effective, easily deployable, highly available SDN based Entreprise WiFi: Improved Control and Customization, Seamless Inter-AP handover Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

6 Motivation Mobile Data Traffic Explosion Exploding growth of mobile network traffic Cisco Visual Network Index (VNI), Feb reports: Tenfold increase in global mobile data from 2014 to Smartphone traffic will be 75% of mobile data traffic by G traffic will be 50% of mobile traffic by Limited availability of wireless spectrum is challenge Approaches studied: Focus on LTE and WiFi SDN Based EPC: Reduce signaling costs in network SDN for WiFi offloading: Cost-effective, easily deployable, highly available SDN based Entreprise WiFi: Improved Control and Customization, Seamless Inter-AP handover Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

7 Motivation Mobile Data Traffic Explosion Exploding growth of mobile network traffic Cisco Visual Network Index (VNI), Feb reports: Tenfold increase in global mobile data from 2014 to Smartphone traffic will be 75% of mobile data traffic by G traffic will be 50% of mobile traffic by Limited availability of wireless spectrum is challenge Approaches studied: Focus on LTE and WiFi SDN Based EPC: Reduce signaling costs in network SDN for WiFi offloading: Cost-effective, easily deployable, highly available SDN based Entreprise WiFi: Improved Control and Customization, Seamless Inter-AP handover Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

8 Software Defined Networking (SDN) SDN involves (among other things): Control logic moved from network elements to software controllers Enabling automation and orchestration of network services Open programmatic interfaces Network Virtualization Services Network Function Virtualization Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

9 SDN Overview, contd. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

10 SDN Overview, contd. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

11 SDN Overview, contd. Claimed Advantages Provides programmatic interfaces to the underlying network hardware. Provides control over network operations via different user written network applications. Enables multiple protocol stacks to share the same physical networking infrastructure via network virtualization. Formal verification and characterization of network behavior Identification of bugs/faults and conduct root cause analysis Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

12 SDN Overview, contd. Claimed Advantages Provides programmatic interfaces to the underlying network hardware. Provides control over network operations via different user written network applications. Enables multiple protocol stacks to share the same physical networking infrastructure via network virtualization. Formal verification and characterization of network behavior Identification of bugs/faults and conduct root cause analysis Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

13 SDN Overview, contd. Claimed Advantages Provides programmatic interfaces to the underlying network hardware. Provides control over network operations via different user written network applications. Enables multiple protocol stacks to share the same physical networking infrastructure via network virtualization. Formal verification and characterization of network behavior Identification of bugs/faults and conduct root cause analysis Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

14 SDN: Potential Applications Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

15 Work in Progress Part I: SDN based LTE EPC Architecture Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

16 Traditional LTE Architecture HSS PCRF MME S11 SGW PGW S1-MME S5 SGi S1-MME S1-U EPC S1-U enb X2 enb LTE-uU LTE-uU UE UE Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

17 LTE Architecture LTE Arch. Components Evolved Universal Terrestrial Random Access Network (EUTRAN) E-UTRAN consists of enodebs (Evolved Node Bs) and User Equipment (UE), i.e. mobile nodes Evolved Packet Core (EPC) EPC LTE Architecture supports distributed control plane EPC consists of: Mobility Management Entity (MME), the Serving Gateway (SGW), and the Packet Gateway (PGW) Packet Gateway (PGW) resides at the edge of network EPS Bearer is the end-to-end data flow connection LTE uses GPRS Tunneling Protocol (GTP) or Proxy Mobile IP (PMIP) protocol for mobility management Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

18 LTE Architecture LTE Arch. Components Evolved Universal Terrestrial Random Access Network (EUTRAN) E-UTRAN consists of enodebs (Evolved Node Bs) and User Equipment (UE), i.e. mobile nodes Evolved Packet Core (EPC) EPC LTE Architecture supports distributed control plane EPC consists of: Mobility Management Entity (MME), the Serving Gateway (SGW), and the Packet Gateway (PGW) Packet Gateway (PGW) resides at the edge of network EPS Bearer is the end-to-end data flow connection LTE uses GPRS Tunneling Protocol (GTP) or Proxy Mobile IP (PMIP) protocol for mobility management Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

19 LTE Architecture LTE Arch. Components Evolved Universal Terrestrial Random Access Network (EUTRAN) E-UTRAN consists of enodebs (Evolved Node Bs) and User Equipment (UE), i.e. mobile nodes Evolved Packet Core (EPC) EPC LTE Architecture supports distributed control plane EPC consists of: Mobility Management Entity (MME), the Serving Gateway (SGW), and the Packet Gateway (PGW) Packet Gateway (PGW) resides at the edge of network EPS Bearer is the end-to-end data flow connection LTE uses GPRS Tunneling Protocol (GTP) or Proxy Mobile IP (PMIP) protocol for mobility management Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

20 LTE Architecture Components MME NAS security Idle State Mobility Handling EPS bearer control SGW Mobility Anchoring when UEs move across differnt enbs. PGW Provides External Data Connectivity UE IP Address Allocation Packet Filtering Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

21 LTE Architecture Components MME NAS security Idle State Mobility Handling EPS bearer control SGW Mobility Anchoring when UEs move across differnt enbs. PGW Provides External Data Connectivity UE IP Address Allocation Packet Filtering Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

22 LTE Architecture Components MME NAS security Idle State Mobility Handling EPS bearer control SGW Mobility Anchoring when UEs move across differnt enbs. PGW Provides External Data Connectivity UE IP Address Allocation Packet Filtering Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

23 Drawbacks of existing LTE Architecture Issues Placement of PGW functionality at edge introduces delay for events such as: Initial Attach Procedure New Access Bearer SetUp/New Flow Entry Procedure Intra LTE Handover Procedure Inter-RAT Handover Procedure Use of tunnel (e.g. GTP or PMIP) introduces: Objective Control plane signaling load Packet header overhead Design a Scalable Control Plane that: Handles efficient control plane signaling to handle global mobile billions of 4G/5G network connections in future Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

24 Drawbacks of existing LTE Architecture Issues Placement of PGW functionality at edge introduces delay for events such as: Initial Attach Procedure New Access Bearer SetUp/New Flow Entry Procedure Intra LTE Handover Procedure Inter-RAT Handover Procedure Use of tunnel (e.g. GTP or PMIP) introduces: Objective Control plane signaling load Packet header overhead Design a Scalable Control Plane that: Handles efficient control plane signaling to handle global mobile billions of 4G/5G network connections in future Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

25 Drawbacks of existing LTE Architecture Issues Placement of PGW functionality at edge introduces delay for events such as: Initial Attach Procedure New Access Bearer SetUp/New Flow Entry Procedure Intra LTE Handover Procedure Inter-RAT Handover Procedure Use of tunnel (e.g. GTP or PMIP) introduces: Objective Control plane signaling load Packet header overhead Design a Scalable Control Plane that: Handles efficient control plane signaling to handle global mobile billions of 4G/5G network connections in future Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

26 Proposed SDN Based EPC Architecture Main Features Control plane functionalities of MME, SGW and PGW are moved to a (logically) centralized EPC Controller SGW and PGW are replaced with an OpenFlow switch The EPC Controller provides flow-based routing Use of GTP or PMIPv6 mobility management protocol is eliminated Solutions based on SDN concepts are designed to provide IP mobility, QoS and security After user mobility, packets are forwarded along updated routes specified by EPC Controller Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

27 Proposed SDN Based EPC Architecture Main Features Control plane functionalities of MME, SGW and PGW are moved to a (logically) centralized EPC Controller SGW and PGW are replaced with an OpenFlow switch The EPC Controller provides flow-based routing Use of GTP or PMIPv6 mobility management protocol is eliminated Solutions based on SDN concepts are designed to provide IP mobility, QoS and security After user mobility, packets are forwarded along updated routes specified by EPC Controller Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

28 Proposed SDN Based EPC Architecture Control Plane Data Plane EPC Controller Internet enodeb enodeb OF-Switch UE OF-Switch /WAG WiFi AP Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

29 Proposed SDN Based EPC Architecture EPC Controller Functionality of MME, SGW and PGW are logically centralized at the EPC Controller : Receives UE authentication and mobility information via TCP interfaces connected to the enb Has global view of entire network (consisting of OF-Switches, enbs and UEs) OpenFlow Switches SGW and PGW are replaced using OpenFlow Switches as forwarding entities: Global network view property of SDN is used to provide IP Mobility GTP and PMIPv6 are not needed in this architecture Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

30 Initial Attach & New Flow/Bearer Setup Procedure UE enodeb MME SGW PGW RRC Connection SetUp Attach Request RRC Connection Establishment Data Radio Bearer Initial Context SetUp Request Initial Context SetUp Response Create Session Request Create Session Response Modify Bearer Request Modify Bearer Response GTP-U Create Session Request Create Session Response Modify Bearer Request Modify Bearer Response Access Bearer SetUp Initial Attach & Access Bearer set up in 3GPP EPC UE enb EPC Controller RRC Connection Set Up Attach Request Assign IP RRC Connection Establishment Proposed Initial Attach Procedure OF-Switch enb EPC Controller OFPT PACKET IN Initial Context SetUp Request Initial Context SetUp Response OFPT PACKET OUT Proposed Flow Entry Procedure Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

31 Intra-LTE Handover Procedure S-eNodeB T-eNodeB MME S-SGW T-SGW Handover Request Handover Request Ack enb Status Transfer Data Radio Bearer Path Switch Request Path Switch Request Ack Create Session Request Create Session Response Delete Session Request Delete Session Response GTP-U Modify Bearer Request Modify Bearer Response PGW Intra-LTE Handover Procedure for 3GPP EPC S-eNB Data Radio Bearer T-eNB Handover Required Handover Request Handover Request Ack Handover Command enb Status Transfer enb Status Transfer Handover Notify EPC Controller Data Packet Flow OFPT PACKET OUT OF-Switch Proposed Intra-LTE Handover Procedure Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

32 Inter-RAT Handover Procedure UE / enb MME p-mag/sgw n-mag Detach Request Delete Session Request Proxy Binding Update (lifetime = 0) Proxy Binding Ack Delete Session Detach Accept Response Connect to Inter-RAT Network Proxy Binding Update Proxy Binding Ack PMIPv6 Tunnel PGW Inter-RAT Handover Procedure for 3GPP EPC UE Detach Request Detach Response EPC Controller Forward Data Flow Binding Entry n-mag Binding Entry Ack OFPT PACKET OUT Forward Data Flow OF-Switch Proposed Inter-RAT Handover Procedure Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

33 Advantages of Proposed Architecture Performs flow mobility without using tunnels and high-volume control signals. Overcomes limitations of protocol stack overhead. Reduces delay for various events such as initial attach and handover. Provides easy integration with cloud technology. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

34 Advantages of Proposed Architecture Performs flow mobility without using tunnels and high-volume control signals. Overcomes limitations of protocol stack overhead. Reduces delay for various events such as initial attach and handover. Provides easy integration with cloud technology. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

35 Advantages of Proposed Architecture Performs flow mobility without using tunnels and high-volume control signals. Overcomes limitations of protocol stack overhead. Reduces delay for various events such as initial attach and handover. Provides easy integration with cloud technology. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

36 Advantages of Proposed Architecture Performs flow mobility without using tunnels and high-volume control signals. Overcomes limitations of protocol stack overhead. Reduces delay for various events such as initial attach and handover. Provides easy integration with cloud technology. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

37 Advantages of Proposed Architecture Performs flow mobility without using tunnels and high-volume control signals. Overcomes limitations of protocol stack overhead. Reduces delay for various events such as initial attach and handover. Provides easy integration with cloud technology. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

38 Tunnel Management Message Sizes in 3GPP EPC Table: Values are based on 3GPP standard specifications Messages Notation Src-Dst Size (Bytes) Create Session Request M csr MME-SGW 335 Create Session Response M csp SGW-MME 241 Create Session Request M csr SGW-PGW 335 Create Session Response M csp PGW-SGW 224 Modify Bearer Request M mbr MME-SGW 101 Modify Bearer Response M mbp SGW-MME 81 Modify Bearer Request M mbr SGW-PGW 67 Modify Bearer Response M mbp PGW-SGW 81 Delete Session Request M dsr MME-SGW 90 Delete Session Response M dsp SGW-MME 18 Delete Session Request M dsr SGW-PGW 90 Delete Session Response M dsp PGW-SGW 18 Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

39 Proposed Architecture: Message Sizes Details in: Chourasia and Sivalingam, IEEE NetSoft 2015, page 5 Messages Notation Src-Dst Size (B) OF Assign IP OF aip enb-ctr 44 OF Initial Context SetUp Request OF icsr Ctr-eNB 82 OF Initial Context SetUp Response OF icsp enb-ctr 42 Handover Required OF hrq enb-ctr 20 Handover Request OF hr Ctr-eNB 62 Handover Request Ack OF hack enb-ctr 42 Handover Command OF hc Ctr-eNB 46 Handover Notify OF hn enb-ctr 30 enb Status Transfer OF est enb-ctr 22 Proxy Binding Update OF pbu Ctr-MAG 38 Proxy Binding Ack OF pba MAG-Ctr 38 OFP PACKET IN OF in OF Switch-Ctr 32 OFP PACKET OUT OF out Ctr-OF Switch 24 Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

40 Signaling Cost Analysis Total size of all control messages required for event completion Numerical results computed based on simple model Signaling Cost (in MB) Proposed - EPC 3GPP - EPC Total Signaling Cost Number of Users Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

41 Implementation Status ns3 Simulator framework done Components used from ns-3 OpenFlow Switch WiFi AP New components added to ns-3 EPC Controller OpenFlow based enodeb Application Testbed Implementation (in progress) OpenLTE: Open source implementation of 3GPP LTE; Used as a base to implement the OpenFlow based enodeb. Floodlight: Enterprise-class, Apache-licensed, Java-based OpenFlow Controller; Used to implement the EPC Controller. Open vswitch (OVS): a multi-layer open source virtual switch, used to implement the OpenFlow Switch. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

42 Implementation Status ns3 Simulator framework done Components used from ns-3 OpenFlow Switch WiFi AP New components added to ns-3 EPC Controller OpenFlow based enodeb Application Testbed Implementation (in progress) OpenLTE: Open source implementation of 3GPP LTE; Used as a base to implement the OpenFlow based enodeb. Floodlight: Enterprise-class, Apache-licensed, Java-based OpenFlow Controller; Used to implement the EPC Controller. Open vswitch (OVS): a multi-layer open source virtual switch, used to implement the OpenFlow Switch. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

43 Simulation Results Topology: 1 EPC Controller, 11 OpenFlow Switches, 100 enbs & 100 WiFi APs Scenario - 50% of the UEs move from LTE to WiFi networks (each second) Average Throughput (Kbps) Average Throughput Without Handover With Handover Number of Users Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

44 Event handling delay Event LTE EPC Proposed EPC Initial Attach Procedure ms 2 ms New Access Bearer SetUp /New ms 2 ms Flow Entry Procedure Intra LTE Handover Procedure ms 26ms Inter-RAT Handover Procedure 565 ms 26 ms Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

45 Ongoing Testbed Work OpenLTE Requirements: Linux PC USRP B210 2 vert900 antennas Floodlight Requirements: Linux PC with Ubuntu (Natty) or higher. Features: Supports OpenStack Handles mixed OpenFlow and non-openflow networks Offers module-loading system Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

46 Ongoing Testbed Work OpenLTE Requirements: Linux PC USRP B210 2 vert900 antennas Floodlight Requirements: Linux PC with Ubuntu (Natty) or higher. Features: Supports OpenStack Handles mixed OpenFlow and non-openflow networks Offers module-loading system Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

47 Ongoing Testbed Work, contd. Open vswitch Requirements: Linux PC with at least two Ethernet interfaces. Features: Full support for OpenFlow 1.3 Partial support for OpenFlow 1.4 and 1.5 IPv6 support Fine-grained QoS control Integration of these components is in progress Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

48 Summary Future Work Summary EPC Architecture is proposed using concepts of SDN. Evaluated proposed EPC architecture using ns-3 simulator in terms of signaling and delay cost. Proposed EPC architecture reduces the complexity of control plane, and reduces the signaling cost and delay for the events. Future Work Implement the proposed architecture in the experimental testbed. Address QoS support in the proposed architecture. Address scalability; controller placement and related issues Evaluate the processing time of the control messages in the proposed architecture using testbed setup Discuss with mobile ISPs (India) about large-scale trials Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

49 Summary Future Work Summary EPC Architecture is proposed using concepts of SDN. Evaluated proposed EPC architecture using ns-3 simulator in terms of signaling and delay cost. Proposed EPC architecture reduces the complexity of control plane, and reduces the signaling cost and delay for the events. Future Work Implement the proposed architecture in the experimental testbed. Address QoS support in the proposed architecture. Address scalability; controller placement and related issues Evaluate the processing time of the control messages in the proposed architecture using testbed setup Discuss with mobile ISPs (India) about large-scale trials Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

50 Work in Progress Part II: SDN based LTE-WiFi Flow Mobility Architecture Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

51 Objectives Mobile data traffic offloading can reduce congestion in LTE core WiFi is a good choice for offloading due to its ubiquity Need to provide seamless mobility between LTE and WiFi Move all flows of a mobile or only selective flows, based on flow s QoS needs Latter is more flexible and consider traffic type Objective: Selective offload of a mobile s flows to WiFi and retain other flows on LTE Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

52 Existing Mobility Management Frameworks Mobile IPv4 (MIPv4): Mobile node has a static IP Home Address (HoA); uses a temporary Care of Address (CoA) when in another network. Mobile IPv6 (MIPv6): Similar to MIPv4. Makes use of IPv6 address auto-configuration to acquire CoA. Dual Stack Mobile IPv6 (DSMIPv6): Allows dual stack mobile nodes to use MIPv6. Proxy Mobile IPv6 (PMIPv6): PMIPv6 provides network-based mobility support, instead of mobile-based. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

53 Existing Mobility Management Frameworks Mobile IPv4 (MIPv4): Mobile node has a static IP Home Address (HoA); uses a temporary Care of Address (CoA) when in another network. Mobile IPv6 (MIPv6): Similar to MIPv4. Makes use of IPv6 address auto-configuration to acquire CoA. Dual Stack Mobile IPv6 (DSMIPv6): Allows dual stack mobile nodes to use MIPv6. Proxy Mobile IPv6 (PMIPv6): PMIPv6 provides network-based mobility support, instead of mobile-based. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

54 Existing Mobility Management Frameworks Mobile IPv4 (MIPv4): Mobile node has a static IP Home Address (HoA); uses a temporary Care of Address (CoA) when in another network. Mobile IPv6 (MIPv6): Similar to MIPv4. Makes use of IPv6 address auto-configuration to acquire CoA. Dual Stack Mobile IPv6 (DSMIPv6): Allows dual stack mobile nodes to use MIPv6. Proxy Mobile IPv6 (PMIPv6): PMIPv6 provides network-based mobility support, instead of mobile-based. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

55 Existing Mobility Management Frameworks Mobile IPv4 (MIPv4): Mobile node has a static IP Home Address (HoA); uses a temporary Care of Address (CoA) when in another network. Mobile IPv6 (MIPv6): Similar to MIPv4. Makes use of IPv6 address auto-configuration to acquire CoA. Dual Stack Mobile IPv6 (DSMIPv6): Allows dual stack mobile nodes to use MIPv6. Proxy Mobile IPv6 (PMIPv6): PMIPv6 provides network-based mobility support, instead of mobile-based. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

56 PMIPv6 Architecture Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

57 PMIPv6 Components Mobile Access Gateway (MAG) Takes care of mobility related signalling on behalf of all Mobile Nodes (MN) attached to its links. Usually carried out by the first hop router for the MN in the PMIPv6 domain, called Local Mobility Domain (LMD). Carried out by S-GW in LTE and WAG in WiFi. Local Mobility Anchor (LMA) Anchor for addresses used by MN in LMD. Stores routing related information. PMIPv6 tunnel is created between the LMA and the MAGs for data transfer. For LTE-WiFi mobility, this is implemented at the P-GW. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

58 PMIPv6 Signalling Mobile Node attaches to MAG1 Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

59 PMIPv6 Signalling, Contd. Mobile node moves from MAG1 to MAG2 Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

60 Issues with PMIPv6 PMIPv6 solves the problem of user session mobility, but does not provide support to move selected flows of a mobile If LMA is implemented in PGW, it increases PGW complexity If LMA is in a separate entity, additional tunneling overhead between PGW and LMA is needed Also, LMA is a single point of failure Proposed architecture combines best of PMIPv6 and SDN Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

61 Proposed Architecture Seamless Internetwork Flow Mobility (SIFM) Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

62 SIFM Components: Flow Controller (FC) FC works like a SDN controller. All flow mobility related signalling and routing is handled by FC. FC is centralized and has complete view of both LTE and WiFi networks. Sets up rules and routing in the flow table located at the MA, based on which flows are forwarded by the MAs. Since flow mobility is handled in each local domain, scalability should not be affected. Easier integration when SDN-based EPC is implemented. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

63 SIFM Components: Flow Controller (FC) FC works like a SDN controller. All flow mobility related signalling and routing is handled by FC. FC is centralized and has complete view of both LTE and WiFi networks. Sets up rules and routing in the flow table located at the MA, based on which flows are forwarded by the MAs. Since flow mobility is handled in each local domain, scalability should not be affected. Easier integration when SDN-based EPC is implemented. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

64 SIFM Components: Mobility Agent (MA) Mobility Agent (MA): a router that provides Internet services to UE MA is responsible for detecting the movement of UE between LTE and WiFi Signals user (UE) movements to FC Provides functions similar to the MAG in PMIPv6 Forwards flows based on the rules set up by the FC Messaging similar to OpenFlow Protocol is used to communicate between FC and MAs Only Control Messages are exchanged between the MAs and FC In SIFM, functionality of the MA is added to PGW and WAG for LTE and WiFi respectively. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

65 SIFM Components: Mobility Agent (MA) Mobility Agent (MA): a router that provides Internet services to UE MA is responsible for detecting the movement of UE between LTE and WiFi Signals user (UE) movements to FC Provides functions similar to the MAG in PMIPv6 Forwards flows based on the rules set up by the FC Messaging similar to OpenFlow Protocol is used to communicate between FC and MAs Only Control Messages are exchanged between the MAs and FC In SIFM, functionality of the MA is added to PGW and WAG for LTE and WiFi respectively. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

66 SIFM Components: Mobility Agent (MA) Mobility Agent (MA): a router that provides Internet services to UE MA is responsible for detecting the movement of UE between LTE and WiFi Signals user (UE) movements to FC Provides functions similar to the MAG in PMIPv6 Forwards flows based on the rules set up by the FC Messaging similar to OpenFlow Protocol is used to communicate between FC and MAs Only Control Messages are exchanged between the MAs and FC In SIFM, functionality of the MA is added to PGW and WAG for LTE and WiFi respectively. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

67 User Equipment (UE) or Mobile Node (MN) UE should be able to receive packets destined to multiple IP addresses at the same time UE should support weak-host model or logical interface. Android supports the weak-host model, Windows does not. Logical interface abstracts the underlying physical interfaces. Logical interface accepts packets from all the underlying physical interfaces. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

68 Working (LTE and WiFi) Mobile Node attaches to a PGW Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

69 Working (LTE and WiFi), contd. Mobile node moves from a LTE Network to a WiFi network Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

70 Implementation Details Binding Cache maintained at FC Every entry has following fields: MN-ID: Identifies Mobile Node MA-ID: Identifies Mobility Agent. MN-IP: IP Address of Mobile Node within MA s network. MA-IP: IP Address of Mobility Agent. This is the tunnel address which is used to communicate with other MAs. PORT-ID: Physical/Logical port on which the packets destined to the MN are forwarded at the MA. STATUS: Status of the UE in a MA s network. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

71 Implementation Details, contd. Flow table maintained at MA Every entry has following fields: Match-fields: Fields of the packet header to match against the incoming packets. It might be an ingress port, source/destination IP etc. Priority: Matching precedence of the flow entry. Counters: Updated when the packets are matched. Instructions: Actions to be performed by the MA on the packets matched. Timeout: Idle time before a flow is expired by the switch. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

72 Implementation Details, contd. Implemented in ns-3 network simulator (v3.20) Added a new module named openflow-hybrid that implements: Flow controller (openflow-external-controller.cc/h) Signalling between FC and MA: Binding Update (openflow-binding-update.cc/h) Binding Acknowledgement (openflow-binding-ack.cc/h) Flow modification message (openflow-flow-mod.cc/h) Port Status Update (openflow-port-status-update.cc/h) UE Logical interface (ue-logical-net-device.cc/h) openflow-hybrid-net-device.cc/h implements the openflow hybrid switch functionality, used by the MAs (PGW and WAG). Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

73 Changes made Changes made to LTE module point-to-point-epc-helper.cc is changed to assign IP to logical netdevice, instead of LTE netdevice. epc-sgw-pgw-application.cc/h is modified to route packets to the UE based on the flow table rules. epc-sgw-pgw-application.cc/h is modified to communicate with the FC to send/receive signalling messages to FC. Changes made to WiFi module ap-wifi-mac.cc/h is modified to communicate with FC to send/receive signalling messages to FC. The openflow-hybrid switch object associated with the AP mac object, takes care of the routing of packets to the UE. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

74 Changes made Changes made to LTE module point-to-point-epc-helper.cc is changed to assign IP to logical netdevice, instead of LTE netdevice. epc-sgw-pgw-application.cc/h is modified to route packets to the UE based on the flow table rules. epc-sgw-pgw-application.cc/h is modified to communicate with the FC to send/receive signalling messages to FC. Changes made to WiFi module ap-wifi-mac.cc/h is modified to communicate with FC to send/receive signalling messages to FC. The openflow-hybrid switch object associated with the AP mac object, takes care of the routing of packets to the UE. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

75 PMIPv6 Implementation in ns3 ns-3 LTE module has been modified to support ipv6. New module named pmip6 has been added to NS3 to support PMIPv6 lma-application.h/cc implements LMA functionalities mag-application.h/cc implements MAG functionalities pmipv6-profile.h/cc implements the user profile for pmipv6 Signalling messages are implemented in ipv6-mobility-header.h/cc and ipv6-mobility-option.h/cc Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

76 Simulation Topology PMIPv6 SIFM Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

77 Simulation Parameters Internet Link Bandwidth 1 Gbps LTE Downlink Capacity 100 Mbps LTE Uplink Capacity 100 Mbps Scheduler Used at LTE Round Robin WiFi Network Capacity 54 Mbps (802.11a) No. of users varies from 10 to 50 Offload value varies from 0% to 30% of the total traffic Traffic at each UE 1 UDP app, 1Mbps, CBR 1 TCP app, 1Mbps, CBR Table: Simulation Parameters Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

78 Throughput and delay comparison Average Throughput (Mbps) Average Throughput per Application Average Delay (ms) Average Delay Number of UEs Number of UEs No offload - SIFM No offload - PMIPv6 10% offload - SIFM 10% offload - PMIPv6 20% offload - SIFM 20% offload - PMIPv6 30% offload - SIFM 30% offload - PMIPv6 No offload - SIFM No offload - PMIPv6 10% offload - SIFM 10% offload - PMIPv6 20% offload - SIFM 20% offload - PMIPv6 30% offload - SIFM 30% offload - PMIPv6 Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

79 Packet loss and handover delay comparison Average Packet loss rate per application Average Packet loss rate (%) Number of UEs No offload - SIFM No offload - PMIPv6 10% offload - SIFM 10% offload - PMIPv6 20% offload - SIFM 20% offload - PMIPv6 30% offload - SIFM 30% offload - PMIPv6 No.of flows Avg. HO Delay Avg. HO Delay offloaded with SIFM (in s) with PMIPv6 (in s) Table: Handover Delay Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

80 Delay comparison with and without flow mobility Average Delay for TCP applications Average Delay for UDP applications Average TCP Delay (ms) Average UDP Delay (ms) Number of UEs Number of UEs No offload - SIFM No offload - PMIPv6 20% offload - PMIPv6 20% TCP offload - SIFM 20% UDP offload - SIFM 30% offload - PMIPv6 30% TCP offload - SIFM 30% UDP offload - SIFM No offload - SIFM No offload - PMIPv6 20% offload - PMIPv6 20% TCP offload - SIFM 20% UDP offload - SIFM 30% offload - PMIPv6 30% TCP offload - SIFM 30% UDP offload - SIFM TCP delay comparison UDP delay comparison Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

81 Throughput comparison with and without flow mobility Average TCP Throughput (Mbps) Average Throughput for TCP applications Number of UEs No offload - SIFM No offload - PMIPv6 20% offload - PMIPv6 20% TCP offload - SIFM 20% UDP offload - SIFM 30% offload - PMIPv6 30% TCP offload - SIFM 30% UDP offload - SIFM Average UDP Throughput (Mbps) Average Throughput for UDP applications Number of UEs No offload - SIFM No offload - PMIPv6 20% offload - PMIPv6 20% TCP offload - SIFM 20% UDP offload - SIFM 30% offload - PMIPv6 30% TCP offload - SIFM 30% UDP offload - SIFM TCP throughput comparison UDP throughput comparison Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

82 Packet loss comparison with and without flow mobility Average Packet Loss Rate for TCP applications Average Packet Loss Rate for UDP applications Average TCP packetloss rate (%) Number of UEs No offload - SIFM No offload - PMIPv6 20% offload - PMIPv6 20% TCP offload - SIFM 20% UDP offload - SIFM 30% offload - PMIPv6 30% TCP offload - SIFM 30% UDP offload - SIFM Average UDP packetloss rate (%) Number of UEs No offload - SIFM No offload - PMIPv6 20% offload - PMIPv6 20% TCP offload - SIFM 20% UDP offload - SIFM 30% offload - PMIPv6 30% TCP offload - SIFM 30% UDP offload - SIFM TCP packet loss comparison UDP packet loss comparison Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

83 Key Results SIFM shows an improvement of 13.86%, 29.05% and 11.33% in terms of delay, throughput and packet loss respectively, over no-offload scenario PMIPv6 shows an improvement of 7.96%, 19.52% and 7.83% in terms of delay, throughput and packet loss respectively, over no-offload scenario Flow mobility support in the SIFM architecture provides flexibility to move selective flows This helps in achieving higher performance gain compared to PMIPv6 architecture Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

84 Key Results SIFM shows an improvement of 13.86%, 29.05% and 11.33% in terms of delay, throughput and packet loss respectively, over no-offload scenario PMIPv6 shows an improvement of 7.96%, 19.52% and 7.83% in terms of delay, throughput and packet loss respectively, over no-offload scenario Flow mobility support in the SIFM architecture provides flexibility to move selective flows This helps in achieving higher performance gain compared to PMIPv6 architecture Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

85 Key Results SIFM shows an improvement of 13.86%, 29.05% and 11.33% in terms of delay, throughput and packet loss respectively, over no-offload scenario PMIPv6 shows an improvement of 7.96%, 19.52% and 7.83% in terms of delay, throughput and packet loss respectively, over no-offload scenario Flow mobility support in the SIFM architecture provides flexibility to move selective flows This helps in achieving higher performance gain compared to PMIPv6 architecture Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

86 Key Results SIFM shows an improvement of 13.86%, 29.05% and 11.33% in terms of delay, throughput and packet loss respectively, over no-offload scenario PMIPv6 shows an improvement of 7.96%, 19.52% and 7.83% in terms of delay, throughput and packet loss respectively, over no-offload scenario Flow mobility support in the SIFM architecture provides flexibility to move selective flows This helps in achieving higher performance gain compared to PMIPv6 architecture Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

87 Testbed Setup SIFM architecture is being implemented in a testbed Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

88 Testbed Setup, contd. OpenLTE requirements: GNU radio or higher Intel i5 processor or higher USRP 210x 2 vert900 antennas iptables at least one USB 3.0 port WiFi AP requirements: hostapd 1.0 dnsmasq iptables Linux PC with at least one ethernet interface and one WiFi interface OpenLTE and WiFi AP are currently tested on Ubuntu Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

89 Testbed Status LTE Network OpenLTE is an open source implementation of LTE enodeb and EPC core. National Instruments USRP B210x, a software defined radio platform, integrated with OpenLTE to implement LTE enodeb. Flow Controller is an application on Linux LTE fdd enb gw.cc, LTE fdd enb main.cc and LTE fdd enb mme.cc files modified to communicate with FC. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

90 Testbed Status LTE Network OpenLTE is an open source implementation of LTE enodeb and EPC core. National Instruments USRP B210x, a software defined radio platform, integrated with OpenLTE to implement LTE enodeb. Flow Controller is an application on Linux LTE fdd enb gw.cc, LTE fdd enb main.cc and LTE fdd enb mme.cc files modified to communicate with FC. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

91 Testbed Status, contd. WiFi Network hostapd, a Wifi hotspot daemon, runs on Linux to convert a PC into a WiFi AP. An interface that communicates with Flow Controller and the hostapd daemon has been developed. The interface developed listens to hostapd for events and communicates with the FC. dnsmasq daemon assigns IP addresses to the WiFi clients that connect to hostapd. Linux ipip tunnel is used for communication between the nodes that act as PGW and WiFi AP. Exploring use of commercial OpenFlow capable access points. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

92 OpenLTE enb running Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

93 UE connected to OpenLTE enb Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

94 Mobile connected to the created test network 4G connection on the LG G3 Successful Ping Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

95 Limitations and Challenges Configuration of parameters in OpenLTE such that the mobile detects the signal is not well documented and differs from mobile to mobile. Trial-and-error needed. End-to-end data connectivity is still under development in OpenLTE. Only ping application is tested. Other applications yet to be tested. At the WiFi side, multiple applications need to be coordinated. Managing all the sockets is the trickiest. Mobile phones need to have both Wifi and LTE turned on at the same time. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

96 Future Work Access Network Discovery and Selection Function (ANDSF) assist the UE to discover non-3gpp access networks. ANDSF provides UE with rules policing the connection to non-3gpp networks. ANDSF along with the proposed architecture can be used to determine the routing of flows dynamically. Algorithms can be developed at the FC, in order to make decisions on the movement of the flow dynamically based on: Current network conditions. User charging profile. User priority. Quality of Service constraints. Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

97 Work in Progress Part III: SDN based Entreprise WiFi Architecture Deferred! Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68

98 Thank You! Krishna Sivalingam (IIT Madras) SDN based Wireless Networks May / 68