Software Defined Networking (SDN) in Telecommunication Industry Jay Ashok Shah Master’s Student Telecommunication & Network EngineeringSouthern Methodist UniversityDallas, Texas, [email protected] Nathalal DubariaMaster’s Student Telecommunication & Network EngineeringSouthern Methodist UniversityDallas, Texas, [email protected] Rajendra Ghogale Master’s Student Telecommunication & Network EngineeringSouthern Methodist UniversityDallas, Texas, [email protected]
Marlyn Scott KinglseyProgram Director Telecommunication & Network Engineering Southern Methodist UniversityDallas, Texas, USA [email protected] Abstract— In today’s world, telecommunication network monitoring operations are becoming tremendous difficult task due to the requirement of more and more bandwidth and network complexity brought by increasing demand of 4G and IP/MPLS network. In this paper, we have summarized few relevant problems that arise in the tests of LTE network devices carried out at the mobile operator in India. The goal of this research paper is to remove the intelligence from each router in a network and keep it into a Software Defined Network Controller. Thus, the controller will have an overview of the complete network which permits to easily and dynamically configure the devices involved in the testing, configuring and monitoring criteria according to the requirements defined by the telecommunication operator ‘Reliance Jio Infocomm Ltd’. Moreover, this will propose the security of the network, as the controller is centralized bringing enhancement to the actual model using NFV and controller Keywords—IP/MPLS, Network Virtualization, Software Defined Network, ControllerI.
INTRODUCTION The intersections of telecommunications, Internet and IT networking paradigms combined with advances in hardware and software has created an environment for rapid innovations and disruptions. This document is aimed at creating a software-based network like SDN 2 which is likely to reshape the telecommunication industry by increasing the flexibility and manageability of networks by delivering bandwidth according to customers needs. The network connectivity architecture is now more elaborated which is hard to resolve, and which is a challenge to meet the business and user requirements of today’s network.
Therefore, in Software Defined Networks 20 its necessary to program switches which are utilized in the modern data centre which will save space, cost and time which in turn increases the KPI and benefits the company. This paper summarizes some tests of LTE equipment carried out at Reliance Jio Infocomm Ltd., (India) which aims to build a compatible hardware/software platform to bridge the gap of problems with solutions. Moreover, the major focus of this paper is to replace existing infrastructure of Reliance Jio architecture model 16 with an end to end IP/MPLS 1 network with its optimal path routing and traffic management functionality. Additionally, we are also trying to merge the existing technology with Software Defined Network which will automate the network and give modern paths to restructure, collaborate and operate networks which indeed will fulfil increasing customer demands and user requirementsII.
BACKGROUNDThe Reliance Jio IP-MPLS 4G network architecture 1 needs to satisfy the increased demand for voice and data traffic. Jio has the customer base of over 100 million working along present conventional architecture and it needs to withstand with the traffic from its customers which is over 100s of terabytes. In India, with 23 telecom circles with over 100 million customers 8, it is difficult task to manage the signaling plane and data traffic with current architecture so by using Software Defined Network we can improve it by introducing segment routing and performance-based intent based networking using telemetry and machine learning.The prior conventional architecture was quite complex and there were many core aggregation routers 17 which in turn made the network a setback. So, by having SDN in control plane, all the network will be transferred and managed, thereby reducing the number of routers and entire network will be centralized by self-optimization of nodes.
Software Defined Networks are driven by centralized software applications, 13 which now will be compatible to upgrade the network and reduce company expenditure on the network devices. SDN controller has the overall map of the network and can route traffic in the backup path if failure is detected.III. ARCHITECTUREFig. 1 Reliance Jio Backhaul NetworkReliance Jio LTE network 18 is divided into two parts i.e.
Backhaul network and Evolved Packet Core network.• Backhaul network will serve the traffic between the eNodeBs and the EPC infrastructure.• Core network will serve IP traffic between circles and Internet traffic towards Point of Presence (POP) location i.e. Mumbai and Chennai. Backhaul network 1 design aims at providing optimal any-to-any connectivity between LTE components, consistent synchronization, guaranteed performance and resiliency across the backhaul.
Below are the components of Backhaul network:• Cell Site Router• Aggregation Routers.• Route ReflectorCell Site Router (CSR) 17 which is co-located with eNodeB. 5eNodeBs are arranged in 1 CSR ring.
Such 5 CSRs are arranged in a ring and 4 rings are dual-homed to an Aggregation Node-1 (AG1) pair. Transport layer for IP backhaul is preferably IP Microwave or Optical Fiber. The basic function of CSR is to help to transport the media IP packets from eNodeB to the core network.Aggregation routers 16 are ASR series routers which connect CSRs to the core network.
Aggregation routers are further divided into 3-levels i.e. AG1, AG2 and AG3. Aggregation Node-1 is a traffic aggregation point for the number of CSS rings i.
e. 4 CSR rings. Traffic from different CSR aggregates at the AG1 node.
The functions of AG1 is it acts as transit LSR (Label Switched Router) as it performs label switching on the traffic flowing between CSR and AG2, it has processor redundancy as it supports nonstop forwarding in case of a processor failure, it helps load balancing the traffic in AG1 ring as it uses ECMP feature. Aggregation Node-2 is a traffic aggregation point for the number of AG1 rings i.e. 10 AG1 rings to a pair of AG2. It functions same as AG1 router with the only difference that it takes care of traffic flowing between AG1 and AG3. The most important function performed by AG2 is the reduction in the number of slaves per grandmaster.
Aggregation Node-3 is a traffic aggregation point for the number of AG2 rings i.e. 4 AG2 forms an AG2 ring which is homed to 1 AG3. It is typically a ‘core router’ which connects different circles to form core network.Route Reflector 16 are layer-3 switches which are co-located with AG3 switches such that they help in reducing the stress on AG3 routers for IP packet forwarding. The basic function of Route reflector is to provide best route path for the IP packet that needs to be transported between the end customers and the external network without creating any burden on AG3 router which forwards the data packets.SAR (Service Aggregation Router) 17 provides connectivity between the Aggregation routers and the core network whereas IBR (Internet Border Router) provides connectivity between IP backhaul network and external network.IV.
SDN CONCEPT DIAGRAM Fig 2 SDN Architecture Concept In the above diagram, the Control Layer/Plane will be ONOS and the Data plane/Infrastructure Layer will be simulated using Mininet 6Fig 3 System Concept DiagramV. HIGH-LEVEL DESIGNA. SDN Controller controlling the Data PlaneFig 4 Controller integrating with P/GW & S/GWThere are two planes in 4G LTE architecture, data plane and control plane. The control plane contains ENode B to MME and data plane is taken care by Enode B to SGW and then to PGW 12.The ONOS controller 5 can be connected to SGW and PGW via southbound API using net flow protocol. SGW will setup GTP tunnel to PGW.
Tunneling the data holds the packet and buffers it when UE goes from one base station to another (Hard Handover). It provides scalability and security to the design. PGW will assign an IP address to the user equipment. It connects to online and offline charging and it is an endpoint to the external network. It does QoS enforcement and data filtering by using the controller.
Fig 5 Controller integrating with MMEB. Controller can be integrated with the MME to be aware of mobility evenThe other part is control plane i.e. the signaling required to make LTE 4G connection by using MME.
MME is the brain behind the network integrated with SDN controller 10. MME selects ENodeB for the user in the area and authenticate the user and assign network resources required for the handover. It provides paging function and mobility management. The challenge for all this networking equipment is to maintain consistency in network connectivity without delay. Since GTP does not support open flow we can replace GTP-u with MPLS network or Ethernet network.
By using SDN controller we can introduce SON functions as well as dual connectivity and coverage capacity optimization.C. SDN with WAN ControllerAs we are going to replace routing information base from route reflector and shifting it to the controller we must convey topology information and routing configuration to the SDN open daylight controller. So, from now onwards all the aggregation routers such as AG1, AG2 and AG3 17 will only handle the user data traffic and the routes will get handled by open daylight controller.VI. NETWORK FUNCTION VIRTUALIZATIONJio’s architecture deployment of new services won’t fetch high cost for integration and operations as over here it will take the overall network and will virtualize it by using a virtual machine such as VMware. The physical routers such as CSR, AG1, AG2 and AG3 19 will become virtual routers and the physical firewall i.
e. Palo Alto which is installed on all routers will become virtual firewalls. This will all run on this NFV infrastructure. These routers will run on Virtual Machines VMs just like Virtual Severs. The implementation of NFV will deliver network functions and software that will run this virtualized instance and this can be deployed on all the core locations in our network as we require without installing the physical hardware devices for each new service which we implement in near future.
This will move service functionality such as load balancers, firewalls etc. and this implementation as a software runs on common server platforms.NFV 14 will transform how the operator will architect their network towards deploying these services on to the virtualization. This will altogether migrate from hardware equipment’s towards software and this not only lowers Capex but also Opex. The services will also be deployed more flexible and will be scaled up and down quickly.VII. SDN CONTROLLERAs we are using Cisco ASR 9000 routers, we will also use their Controller. It has the wide product line which supports programmability and SDN.
Cisco Open SDN Controller i.e. OSC is the SDN controller 3 which is going to be implemented in the architecture.
This is the commercial version of Open Daylight Controller. Open Daylight license version will allow any vendor to take their open source code and package it with additional code and support. This will be the free open source product.The Open SDN model centralizes the control plane functions with the control of the network done by the controller and the related applications such API and NBIs. The ONFs Open SDN model will play a big role in this architecture. ODL will be backed up by many vendorsOpen Day Light 4 has many features with many South Bound Interfaces and many Core features. A vendor can take ODL: use the parts that make sense of the vendor add to it and will create a commercial ODL controller.The API will be used to exchange data with the controller and it will learn information about the network.
The API will also program the network which will ask the controller to add the specific match/action logic flow into the forwarding tables of the networking devices. Different vendors have different APIs 7 and all will be assigned to the controller. When SDN runs, the application running on the same system as the controller, the API does not need to send messages over a network as both the programs are running on the same system.
But when the application runs on a different system, the API will send the data back and forth over the network.Fig 6 Open Day Light ControllerA. HIGH AVAILABILITY FEATURES Stateful switchover(SSO): It is used within the hardware of ASR 903 routers, there are two 2 RSPs in ASR 903 routers 19out of which one is active and other is standby, so we have RSP redundancy.Graceful restart (Non-stop forwarding): In AG1, there is a redundant RSP for control plane taking switchover, so graceful restart is helpful for AG1 to switchover its RSP when there is a point of failure. It will maintain its routing table and label information as stable mode while traffic is not affected. NSF will not work without SSO. CSR does not know about switchover because its holdover time is very less.Fast Reroute (LDP/FRR): Whenever the main path fails normal router will take time to calculate the alternate backup path, so until the alternate path will get active the routing will get interrupted.
So Fast re-route is the feature which will reduce this computational time to less than 50m sec by pre-calculating alternate path. So, whenever router’s best path fails it will automatically switch over the backup path to reduce the traffic loss.BGP- Prefix Independence Convergence(PIC): PIC enhances BGP convergence, regardless of the several BGP prefixes. PIC stores BGP backup/alternate path for each prefix in BGP, RIB, and FIB tables. When the primary goes down, CEF quickly selects different egress port for the affected destination.
BGP route reflectors 1 will compute the best path over the sessions. Whenever next hop fails, hiding the path enables fast convergence and local recovery because the network will wait for BGP CP convergence to restore the traffic. The advertisement of BGP prefix replaces the earlier prefix which is also called as an implicit withdraw. BGP additional path feature allows advertisement of additional multiple paths with the same prefix. So, whenever BGP goes down we have BGP-PIC.B.
ONOS CONTROLLER Fig 7 ONOS ArchitectureONOS 5 is the open network operating system SDN controller platform that supports the transition from legacy “brownfield” networks to SDN “greenfield” networks. This inhibits exciting new capabilities, and disruptive deployment and operational cost points for network operators. ONOS is the only open source controller providing: Scalability, High performance, resiliency, legacy device support and next-generation device support.ONOS provides the interoperability between various vendors as Jio is using CISCO and JUNIPER routers in their architecture.
In Fig 7 the Blue Switches will be Simulated using Mininet software 21.C. MININET Mininet 21 creates a virtual network environment, running real kernel on Linux or Windows or Mac, switch and application code on a single virtual machine or instance like VM, cloud with a single command.This can easily interact with the network using the Mininet CLI and API customize it, share it with others, or deploy it on real hardware.
Mininet is useful for development, teaching, and research.Mininet is also a great way to develop, share, and experiment with Open Flow 14 and Software-Defined Networking systems. Mininet is actively developed and supported and is released under a permissive BSD Open Source license Fig. 8 Snapshot of ONOS CLI Fig. 9 GUI of topology in ONOS Fig.10 Ping test from Host node 1 to node 2Fig. 11 Python Script in ONOSVIII. USE TEST CASES Fig 12 Test Use CasesA.
MANUAL TESTING Whenever the Gx link air interface fails between PCRF to Serving GW entire data traffic from the users to Packet GW will not be able to go over the internet, so it will cause 30 mins of outage for that S-GW affecting the entire region. In that region, all the customers will face the issue of accessing the Internet and entire region get isolated, so it will affect largely on business KPI. For manual testing 11 using iperf test, it will take around 30-45 min to resolve the problem and restore the traffic outage using a man and iperf test, over GTP tunnel.So, we can reduce this outage to just 5mins by SDN as whenever a GX link fails, SDN controller will detect it and run the iperf test using ReST API and identify the root cause and it will suggest the action to be taken. In this way, we can reduce the outage using SDN Controller using OpenFlow Protocol 7.
B. SDN CONTROLLER Over here it will take the overall network and will virtualize it by using a virtual machine such as VMware. The physical routers such as CSR, AG1, AG2 and AG3 16 will become virtual routers and the physical firewall i.e.
Palo Alto which is installed on all routers will become virtual firewalls. This will all run on this NFV infrastructure. These routers will run on Virtual Machines VMs just like Virtual Severs.
IX. BENEFITS1. As most of the network devices are less effective during high traffic hours so energy savings is helpful using SDN.2.
SDN will help in reducing the call drops issues improving network quality3. SDN address key issues such as poor network quality and call drops. SDN helps in replacing several odd purpose-built hardware-centric solutions running on city infrastructure with few on-demand software solutions facilitating various Smart Cities’ project 9.4. If we want to implement additional network services in a city then by implementing SDN the network will be running faster compared to the traditional network, making the network more intelligent and smarter 2.5. In a mission-critical solution, there is improved resiliency, redundancy and reliability of the network.
6. To face training cost of the single tool unlike existing network with more number of vendors, we needed more trained people having an expertise of many vendors equipment but now by this controller, we have reduced manpower by increasing efficiency.7. As SDN is now the only controller 13 which will handle the entire network there will be simplicity in GUI which in turn will help to monitor, operate and manage the network with fewer efforts.X. FUTURE SCOPE A. FIBER TO THE HOME • FTTx – Fiber to the x, is the deployment of fiber (optical) cable to a specific location regarding the customer premise.
The “X” is used to describe the specific application of the service like home (FTTH) 18, building (FTTB) etc.• The FTTx network has important features as:a. Support of Ultra high bandwidth to each customer i.e.
speed of 100 Mbps or more.b. Its extended distance reaches 10km+ as compared to copper which is less than 1kmc. Passive in nature (no power required at any stage except at OLT and customer end device).d. Immune to interference and distances.Fig 13 FTTH Fiber to the HomeB.
Adding Enterprise Customer with Planning and Provisioning of new area or city If in future if enterprise customer wants to purchase dedicated lease line from Reliance Jio. We can provide 20Gbps ++ bandwidth with dedicated lease line to the enterprise customers according to customer’s voice, video and data bandwidth requirements. By using SDN controller we will easily maintain the stringent SLA.
Whenever planning and installation of new sites came in the new area or the city, the installation and commissioning of the hardware devices 15 cost us huge capital expenditure so instead of that by using virtual switches and routers we can easily install and do the commissioning of the new sites. We can live those sites easily by using SDN controller.Fig 14 Addition to Enterprise CustomerXI. CONCLUSION Our paper is an extended version of a collaboration of the presently implemented Reliance Jio architecture with the SDN technology. SDN makes provision for centralized networking. This makes centralized enterprise management 2 easier. By the abstraction of the control and data planes, the SDN accelerates service delivery and provides more agility in provisioning both physical and virtual network devices from a central location.
The SDN provides a single set of APIs’ to create a single management console using GUI 20 for physical and virtual devices. The security aspect also becomes centralized. The SDN controller distributes the security and information policies consistently throughout the enterprise. Centralizing security control into one entity, like the SDN Controller has the disadvantage of creating a central point of attack, but SDN can effectively be used to manage security throughout the enterprise if it is implemented securely and properly. The ability to shape and control data traffic is one of the primary advantages of software-defined networking. Being able to direct and automate data traffic makes it easier to implement quality of services (QoS) for voice over IP and multimedia transmissions.
Streaming high-quality video is easier because SDN improves network responsiveness to ensure a flawless user experience.REFERENCES1 IP/MPLS based backhaul, Core and Optical Transport Network Architecture V1-RAN Core Technologies.2 Software Defined Networks- A Comprehensive Approach by Paul Gorranson and Chuck Black3 DFW Cisco Users Group NFV / SDN 101 Bryn Pounds Solutions Architect – Cisco Systems.
4 Model Defied Networks Using OpenDaylight- © CISCO.5 Basic ONOS Tutorial https://wiki.onosproject.org/display/ONOS/Basic+ONOS+Tutorial6 Author: Quentin Monnet https://qmonnet.github.
io/whirloffload/2016/07/08/introduction-to-sdn/7 Open Flow Switch Specification https://www.opennetworking.org/images/stories/downloads/sdn-resources/onf-specifications/openflow/openflow-spec-v1.
3.1.pdf8 Reliance Jio Network Operator https://www.jio.com/en-in/apps9 Introduction to Software Defined Networking- Teachings by Prof.
Ahmed Sidiqui 10 Software Defined Networks – Lectures and Videos by Dr. Klyne Smith11 SDN-Use Cases, Technical Fundamental Training: Ericsson12 Ericsson LTE Core – High-Level Design Wireless13 Software Defined Networking by Thomas Nadeau and Ken Gray14 Open Networking Foundation ONF: Architecture of SDN 15 A Survey of Software -Defined Networking: Past, Present and Future Programmable Networks, version 5, 2014 16 Reliance Jio LTE Architecture Overview 17 CSS/AG1 Technology Overview by RJIL18 Reliance Architecture and Technology by Reliance Jio Infocomm Ltd19 Samsung EPC System Overview by Samsung Electronics20 Advances in LTE Network Monitoring: a Step towards an SDN Solution, 17th IEEE Mediterranean Electro Technical Conference,201421 Mininet http://mininet.org/