F5 Traffix Use Cases for SDC Diameter Load Balancer

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1 F5 Traffix Use Cases for SDC Diameter Load Balancer

2 Traffix Signaling Delivery Controller (SDC) Load Balancer: Scalability for the Signaling (Control) Plane Real life use cases for Diameter Control Plane Scaling Next-generation cellular applications and smart phone usage consume tremendous wireless data capacity. Scaling the control plane with load balancing Diameter solutions to enable wireless transactions is imperative to increase revenue and ensure customer satisfaction. The F5 Traffix Diameter SDC Load Balancer is one of three solutions in the Traffix Signaling Delivery Controller, a native Diameter network entity. It was designed to support message-based load balancing, allowing for contextual load balancing in the Diameter Control Plane and resilience to failovers and traffic spikes. An important part of any control plane architecture, this technology supports the introduction of scalable and efficient Diameter-based 4G services. Load Balancing Diameter in a Prepaid Intensive Environment What if a large percentage of a service provider customer base is pre-paid and they all consume increasingly sophisticated applications on their smartphones? Each and every pre-paid data transaction needs to be authorized, between a Diameter Client (e.g. GGSN or Gateway GPRS Support Node) and a Diameter Server (e.g. OCS- Online Charging System). Data traffic is only allowed after the user's account balance is verified a great challenge given the exponential increase in cellular data traffic and sheer transaction volume. To make things worse, OCS response time is slower than GGSN requests; as a result, load balancing is required between many OCS Diameter Servers and less corresponding GGSN Diameter Clients. Outages mean" no business". No real time transaction authorization? No revenue, less pre-paid service availability and less customer satisfaction.

3 Scaling with Traffix Diameter Load Balancer With dozens of GGSNs and OCSs, load balancing control plane traffic is a necessity. The load balancing algorithms in the Traffix Diameter Load Balancer direct each request to the right online charging system(ocs), enabling real time authorization of pre-paid data traffic and ensuring availability, service revenue and customer satisfaction. Load Balancing in Asynchronous Messaging Environments What if GGSN simple client re-boots result in service failure? GGSN client reboots in service provider environments should go unnoticed and leave traffic and availability unaffected. Sometimes service provider customers are experiencing the exact opposite. In theory, a GGSN failover should not be a significant event, and should not cause service failure. However on the OCS side, this can become a problem. One service provider saw that in the few seconds when the subscribers were re-registering at the GGSN, the OCS was receiving millions of transactions. The OCS was unable to accept the transactions and ended up overloading. Subscribers were experiencing service interruption. Scaling with Traffix SDC Diameter Load Balancer Traffix SDC Diameter Load Balancer solves this issue in two ways: It diverts peak time transactions into several OCS nodes, avoiding a bottleneck on one OCS; or In cases with one OCS, the Traffix SDC Diameter Load Balancer filters the traffic to prevent OCS overload. It informs the Diameter client side that some of the transactions are rejected and should be resubmitted based on an interaction between the load balancer and the GGSN only.

4 Contextual Load Balancing for Different Subscriber Segments What if three segments of subscribers premium, pre-paid and occasional receive the same service level and are experiencing a higher degree of outages regardless of their SLA? When data traffic increases, operators want to preserve service availability to premium subscribers which paid the most for the service and are more sensitive to service failure. Without load balancing in the control plane, operators find it difficult to differentiate between the different types of service levels per subscriber although they know that some subscribers are more sensitive to service degradation than others. The Benefits of Contextual Load Balancing Traffix SDC Diameter Load Balancer was built to support session-based load balancing, taking into account that Diameter is a message-based protocol. By performing contextual load balancing based on customer type, service type and system load the operator was able to optimize the service across all three subscriber segments and enforce service policies. The algorithm that was selected was one that allowed maximum service quality and service availability to the premium subscribers and allowed occasional users to use the service only in cases where this could be done without impacting the first group. Load Balancing based on server loading What if you would know how busy the destination is where you want to load balance? Wouldn t it be great to temporarily reduce the load to a server that is already having difficulties catching up or soon will have problems? In theory, if all servers out of a server pool all would perform exactly the same at all moments in time then no bidirectional load balancing would be needed. However on the destination side (for instance a poll of OCS servers), a problem at one specific server could pop-up like for instance a CPU being degraded or a maintenance task is being performed. On the source side you would like to adjust the load balancing

5 in such a way that the server with temporarily lower performance is relieved a bit untill it performs back to its normal level. Bi-directional load balancing, reading the servers performance with Traffix SDC Diameter Load Balancer Traffix SDC Diameter Load Balancer solves this issue in two ways: It can adjust automatically the load balancing algorithm if certain SNMP traps are being fired (like system backup, CPU overloaded, etc.) and diverts transactions into the other servers (eg OCS nodes), avoiding a bottleneck on one server could become a service affecting problem, or It reads on a real time basis the delay in messages response time and compares that with all nodes out of the server pool. If one server has a predefined deviation from the average of more than X percent, then obviously that server has some performance problems and will be relieved from heavy traffic till the performance gets back to the average level for the same amount of traffic. In this way the Load Balancer can adjust to real time traffic changes without manual interaction and avoids service impacting problems Scaling the Control Plane with Traffix SDC Diameter Load Balancer Specifically designed for message-based load balancing Native Diameter entity to support contextual load balancing based on message, AVP or content Stateful/Stateless Diameter Relay Agent for Diameter Load Balancing Diameter Proxy Agent for AAA capabilities and policy enforcement Load Balancing resilience to cope with Diameter server and client failover Dynamic service monitoring technology to bypass bottlenecks and enhance performance Supports over 50 Diameter interfaces (3GPP Rel. 8, 9, 10 and 11), TISPAN, Packetcable) including non-standard attribute value pairs from leading industry vendors Traffix SDC offers carriers the ability to control and manage their network in a harmonized manner, not based on function level or data center level but taking into account the entire network load, routing and

6 management policy. This enables to encounter and bypass local issues and to manage the network in a much more scalable and efficient manner. Stateful Session Load Balancing GGSN-1 Session 1 Session 2 Session 3 SDC Session 1 Session 3 Session 5 OCS-1 GGSN-2 Session 4 4 Session 5 5 GGSN-3 Session 5 Session 2 Session 4 Session 6 OCS-2

7 About F5 Traffix Traffix Systems is part of F5 Networks, the global leader in Application Delivery Networking (ADN). Traffix, the 4G & Diameter experts lead the market with a range of Diameter products deployed at over 100 locations worldwide. Powered by the largest workforce dedicated only to Diameter signaling solutions, F5 Traffix supports service providers as they build high-capacity, high-performance 4G networks. The F5 Traffix Signaling Delivery Controller (SDC) platform enables full connectivity, unlimited scalability, and comprehensive control for operators to upgrade their control plane for the demands of a data-dominated world. For more information, visit or