An Oracle White Paper December The Time for Diameter Is Now: Why Service Providers Should Implement Diameter Today

Transcription

1 An Oracle White Paper December 2013 The Time for Diameter Is Now: Why Service Providers Should Implement Diameter Today

2 Introduction There is little secret about how smartphones and tablets are affecting the world s networks. These devices have enabled subscribers to access the internet anytime, anywhere. And with the introduction of social networks such as Facebook and LinkedIn, subscribers are connecting and staying connected all day. The impact on service providers is large. They are seeing their revenue steadily decline, while the cost of their network infrastructure continues to increase. To add insult to injury, over-thetop (OTT) service providers such as Google, Apple, and Amazon.com continue to reap the harvest of these very subscribers at the cost of the service provider. Mobile revenue has shifted; 50 percent of the revenue now goes to Google, Apple, Amazon.com, and Facebook. According to Apple, more than half a billion people have Apple itunes accounts, a number that dwarfs most mobile service providers. Facebook touts more than 700 million daily active users and growing. This means that revenue will continue to move in their direction, away from the network service provider and directly into the coffers of the OTT players. At the same time, the explosion in data traffic has already crippled many networks. Outages in several major networks were the direct result of excessive data traffic and the lack of any congestion or bandwidth management controls. A recent outage at NTT Docomo is a good example: The network was thought to have been engineered to withstand normal data demands, but a single event resulted in an outage that lasted more than five hours and affected 2.52 million subscribers. Network service providers have to spend budget in emergency situations such as these to fix the overwhelming demand of traffic in their networks. This is capital expenditure (CapEx) that was targeted elsewhere but diverted to patch the gaping hole in the packet network capacity. 1

3 So how do network service providers move the data revenue back into their coffers while implementing traffic controls? Do you have to move to Long Term Evolution (LTE) or an IP Multimedia Subsystem (IMS) to enable new services? The answer is no. Network service providers can take advantage of a packet network today, without waiting for LTE at the radio access network (RAN). This means that 3G networks can also realize many of the advantages that LTE brings by simply implementing Diameter in the core network, and with it entities such as the Policy and Charging Rules Function (PCRF). Diameter is the signaling protocol that is rapidly replacing Remote Authentication Dial-In User Service (RADIUS) and Signaling System No. 7 (SS7) throughout the network and in LTE becomes the signaling protocol through which all entities speak. Diameter is also the protocol used in the new charging architecture, which means that service providers can take advantage of Diameter throughout the network and not just in the core. This is the new Diameter network. There are many advantages to this approach, which this white paper examines individually. 2

4 The Need for More Competitive and Personalized Services Subscribers are spending more and more money on games, books, videos, and other products that are sold by device and OTT application service providers. Service providers provide a pipeline to those products and services. The pipeline alone does not bring a premium. However, if the pipeline can be tailored to each subscriber s specific requirements, they are willing to pay for that significant value. Service providers can personalize service and enable subscribers to tailor their online experience to their needs. At the same time, they can differentiate themselves from all the other service providers. There are a number of ways to personalize services, but they all have one thing in common. The Diameter network runs the controls that enable personalization through network elements such as policy and subscriber data management (SDM). The Diameter network and packet core enable service providers to streamline their networks and take advantage of Internet Protocol (IP) as the network transport mechanism, while adding the intelligence and security that the Diameter network offers. The Diameter protocol continues to grow as the Third Generation Partnership Project continues to define new uses for Diameter throughout the network. Because of the unique flexibility of the Diameter protocol, allowing for extensions to the protocol while maintaining backward compatibility, service providers can be assured that Diameter will service their networks well into the future. Provide More Value to Over-the-Top Providers and Subscribers The Diameter protocol provides service providers with the capability to interconnect to OTT providers through a secure connection point. This is important because it safeguards the identity of subscribers as much as possible. However, it is just as easy to provide the enriched information of Diameter to another provider as part of a premium interconnect service. For example, a service provider might implement a partnership with another content provider in which the subscriber s device type and access network are provided. Such a partnership would enable the OTT provider to customize its content for the specific device type and access technology, thus improving the customer experience. This makes the network that much more valuable to the OTT provider, or any other partner that might be looking to share network resources. For example, Mobile Virtual Network Operators can benefit from a Diameter interconnection and the secure sharing of subscriber data and policy rules. More Revenues Back into the Network Diameter is an enabler that allows for service providers to implement more network services that carry a premium to other network providers and subscribers. Diameter is also the technology that ensures secure connections by using encryption, a much stronger security mechanism than what is used in present-day SS7. 3

5 Invest in Diameter Now to Stay Competitive and Control Costs Diameter is the replacement protocol for SS7 and RADIUS. Even if LTE is not being implemented today, it is highly efficient and cost effective to deploy a Diameter core network now. As service providers begin deploying new network elements that support Diameter, it makes more sense to connect to these devices using the Diameter interface, instead of using mediation to convert these interfaces back to SS7 / mobile application part or RADIUS, and then later moving them back to Diameter. This means making a temporary investment in mediation that will be thrown away later, not to mention the wasted labor costs to implement mediation. Deploying a Diameter core now gives service providers the luxury of interconnecting new elements directly into the Diameter core once, without having to redesign the network later when LTE services or any other next-generation wireless technology are launched. By making this investment now, service providers can begin the migration to an all-ip network immediately, and then add other key functions to the network as services grow. This is far better than redesigning the network several times as more speed is added to the RAN. If service providers wait until LTE, routing tables will have to be changed several times in several different locations, which is time consuming and risky, because errors often lead to outages and service disruptions. Diameter Advantages in the 3G Domain The main advantage of Diameter in the core is the capability to personalize services for subscribers using the policy server (the PCRF). This network element uses Diameter to communicate with other parts of the network where the policy enforcement is actually implemented. Present-day Serving Gateway Support Nodes and Gateway GPRS Support Nodes (GGSNs) already have a Diameter interface, in most cases. This means that the PCRF can be implemented throughout the network, and traffic management can begin immediately without launching LTE. This also means that service providers can offer tiered services, day passes, and other personalized services provided using the quota management capabilities of the PCRF and subscriber information in the integrated Subscriber Profile Repository (SPR), and begin adding value to the 3G network while planning for 4G at a later time. The argument could be made that LTE does not ensure that any service provider will be able to increase its average revenue per user without also implementing Diameter in the core and offering personalized services. This makes the case for implementing Diameter now even stronger. Implement Internet Protocol in the Charging Domain IP brings many advantages by itself, and certainly everyone has recognized the value of using IP in the core of the network. However, IP is just as important for charging. In fact, charging can benefit from IP immediately, eliminating a major headache for service providers. 4

6 To implement IP in the charging network, Diameter is used to interconnect all charging entities into the charging systems, both online and offline. IP has been recognized as a major advantage in the billing domain as more and more data is being generated for billing. This is especially true in online charging domains. There are numerous messages between the various network elements delivering a service to the OCS. Credit balance, authorizations, and credit notifications generate a great deal of data back into the core to the numerous service delivery platforms in the network. As subscribers use more and more data for services such as video, longer data sessions for social networks, and e-commerce, this traffic continues to grow in volume. This makes the case for moving to IP and Diameter even stronger today. Implement Policy to Manage Data Traffic and Deliver New Services A policy server is a Diameter-based entity that was introduced as part of the LTE architecture but has since been implemented in 3G networks where Diameter is implemented. Policy enables service providers to implement controls on a per-subscriber basis for managing data traffic. This is important because networks with no policy have required higher CapEx to support data growth, while those with policy have reduced capital and operational expenditures. Why? Because they are now able to control how much bandwidth each subscriber is allowed to consume, when they are allowed to consume it, and how they are allowed to use it with social networks or other OTT services. Policy is the only means for a service provider to get control of the packet network while also introducing new and interesting revenue opportunities. The first implementations of policy were about bandwidth control, but service providers then learned they could charge some subscribers more than others through usage-based service plans. There have been many more creative applications of policy in which new revenues are being recognized by adding value to OTT applications such as Facebook and YouTube. For example, a network service provider realizes that the majority of its subscribers are paying for lower-tier services but they occasionally like to access YouTube. With their current service plan, they are not allowed enough bandwidth to stream videos so their YouTube experience is not a positive one. However, YouTube could be willing to subsidize their service plan by paying the network service provider a premium to allow subscribers in the lower tiers more bandwidth when they access YouTube, provided they opt in. In this way, service providers can improve the subscriber experience. Such customization relies on the Diameter protocol to communicate the rules between a policy server and the policy enforcement entities in the network. Without Diameter, a policy server would not be capable of communicating with the other entities without expensive mediation equipment. 5

7 Diameter Signaling Router for 3G Diameter is the next-generation technology for control throughout the network, but it is also the nextgeneration protocol for services and charging. What is missing from the Diameter network is a centralized point of control and routing a centralized routing function that acts as the hub in the Diameter network and provides security, load balancing, and congestion control. The Diameter signaling router (DSR) is designed to provide these functions and prevent service providers from deploying a mesh network. Mesh networks have never worked historically and always create major concerns for networks for a number of reasons. Routing tables are the biggest issue, because every network element must not only connect to all the other network elements, but also be capable of routing to all the other elements. This results in complex routing tables that have to be repeated at every element. Congestion control and load balancing are another issue in a mesh network. Service providers already use load balancers at the edge of their networks in an attempt to increase the efficiency of the network. However, these point solutions do not scale, and as traffic increases, the load balancers quickly become overwhelmed. Load balancers are also designed to manage connections and not data, so when a connection is lost, which happens frequently in IP networks, the load balancers have to be manually reset to properly balance loads across many connection points. There is no security in a mesh network. Routing details have to be provided at every node, thereby making it impossible to hide the addresses of your most-critical network elements. This makes connecting to other networks especially precarious, because addresses stored in the HSS and sometimes policies in the PCRF must be shared with interconnect partners, exposing the network. A DSR resolves all these issues by acting as a centralized connection point for all routing. Routing translations in other network elements is simplified, because as new elements are added, only the address of the DSR needs to be added. The DSR then makes all routing decisions for the network. A DSR also provides load balancing. Because it is a Diameter routing agent (DRA), it can determine the best routes for all data and, based on data volume, select the best route to be taken. But DSRs provide other values as well. When deploying a PCRF or when converting the charging network to IP, the DSR provides valuable services. Diameter Signaling Router as a Policy Proxy When implementing policy in the network, there is a requirement for a policy rule to be connected to a subscriber. For example, whenever subscribers begin a data session on their phone and they connect with the GGSN, the GGSN needs to send a query to the proper PCRF to receive the rules to be applied to those subscribers. There is more than one PCRF in any tier 1 network, so this can be a challenge. There needs to be a function in the network that can route these queries from the GGSN and deep packet inspection platforms to the proper PCRF. 6

8 This is known as subscriber policy binding and is a function of the DSR. The DSR maintains a routing table that associates each subscriber with a specific PCRF, and can then route policy queries from any network element to the proper PCRF in the network. A DSR provides this function today in tier 1 networks, enabling them to efficiently manage their PCRF connections in the network and centralize the routing functions associated with policy to the DSR. DSR as a Charging Proxy Just as the DSR does for policy, it can also provide a charging proxy function to the network. When changing to IP in the charging network, there are many servers behind the OCS. Reaching these servers requires routing tables in all the entities responsible for generating charging records. To make matters more complex, the servers are used for different services and different subscribers. This means that there is a need for an additional level of intelligence in the charging network that is able to route charging messages to the correct charging platforms, without creating huge and complex routing tables all over the network. The DSR works as an excellent charging proxy, providing a routing function while adding another level of security to the charging network. Using the same security algorithms used for the rest of the network, the DSR ensures that the charging network is able to take advantage of IP Security (IPsec) throughout the network. DSR as an Interconnect Security Gateway When connecting to a partner network for roaming or shared services, it is imperative that there is a single connection point, rather than unbridled access to all the network elements in your domain. This is especially true in Diameter. It is for this reason that the DSR is the best means of supporting interconnections to other networks, just as Signal Transfer Points (STPs) function in the SS7 network. However, an STP is limited to gateway screening, which is not encrypted and not as secure as what Diameter is capable of offering. A DSR provides security in the network through IPsec in the core and Transport Layer Security to outside networks. IPsec uses encryption on a peer-to-peer basis, which means that the message is encrypted each time it passes through another DRA. This is the strongest means of encryption, and only those network elements acting as a DRA with encryption keys can decipher a Diameter message. This makes an excellent interconnect gateway when connecting to outside networks. Topology hiding enables the DSR to substitute the address of any sending network element when sending outside the network, and maintain a connection map internally so it knows where to send responses. 7

9 Conclusion The Diameter protocol is an enabler. It allows service providers to add new functionalities to their networks that bring added value to services. The value add enables service providers to deliver more than just a pipeline, and subscribers are willing to pay for this value. To take advantage of Diameter, some fundamental changes must take place. Of course, Transmission Control Protocol / Stream Control Transmission Protocol / IP is the transport in the new Diameter network, and needs to be deployed throughout the core, as well as in the back office to support charging systems. A DSR is the best means of managing the Diameter network and serves as the focal point for managing connections in the network. It is the most critical component in the new Diameter network and should be the first addition to a 3G network before jumping on the 4G bandwagon. The new Diameter network is the foundation of a successful mobile data business. When implemented properly, it will enable service providers to begin reaping new revenue now without waiting for LTE. 8

10 Appendix: Acronyms and Initialisms AAA Authentication, Authorization, and Accounting AVP Attribute Value Pair BSS Business Support Systems CSCF Call Session Control Function DSR Diameter Signaling Router GGSN Gateway GPRS Support Node HSS Home Subscriber Server IMS Internet Protocol Multimedia Subsystem IOT Interoperability Test RF Radio Frequency LTE Long Term Evolution M2M Machine-to-Machine MME Mobile Management Entity OCS Online Charging System OFCS Off-line Charging System OSS Operation Support Systems OTT Over-the-Top PCRF Policy and Charging Rules Function QoS Quality of Service RAN Radio Access Network SDM Subscriber Data Management SGSN Serving GPRS Support Node S-GW Serving Gateway SPR Subscriber Profile Repository SS7 Signaling System No. 7 STP Signal Transfer Point TDM Time-Division Multiplexing UDR User Data Repository 9

11 The Time for Diameter Is Now: Why Service Providers Should Implement Diameter Today December 2013 Oracle Corporation World Headquarters 500 Oracle Parkway Redwood Shores, CA U.S.A. Worldwide Inquiries: Phone: Fax: oracle.com Copyright 2012, 2013, Oracle and/or its affiliates. All rights reserved. This document is provided for information purposes only, and the contents hereof are subject to change without notice. This document is not warranted to be error-free, nor subject to any other warranties or conditions, whether expressed orally or implied in law, including implied warranties and conditions of merchantability or fitness for a particular purpose. We specifically disclaim any liability with respect to this document, and no contractual obligations are formed either directly or indirectly by this document. This document may not be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without our prior written permission. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Intel and Intel Xeon are trademarks or registered trademarks of Intel Corporation. All SPARC trademarks are used under license and are trademarks or registered trademarks of SPARC International, Inc. AMD, Opteron, the AMD logo, and the AMD Opteron logo are trademarks or registered trademarks of Advanced Micro Devices. UNIX is a registered trademark of The Open Group. 1213