Revolutionising the Performance of Your Applications

Transcription

1 Revolutionising the Performance of Your Applications T he application landscape is changing. Applications are being centralised, whether that be on premise or in the cloud, and the number, and type, of connected devices (IoT) is dramatically increasing. In addition, bandwidth hungry applications, such as video, are on the increase, all adding congestion to already strained networks. With three out of four organisations reporting no increase in budget (Nemertes Research, Benchmark Emerging Trends) poor user performance and frustration in traditional network services is to be expected. However, organisations need applications to perform for the business to perform, whether that is employees accessing the applications to do their job or customers interacting to make a purchase applications are key. So with no additional budget but an increasing need for performance and availability, could the next generation of software defined networks, provide an answer? In our paper SD Revolutionising the Performance of Your Applications, we look at the challenges faced by typical network designs that are implemented today, how QoS profiles are defined, what the limits of these profiles are and finally we consider whether the new breed of intelligent SD s can provide a solution. With no additional budget but an increasing need for performance and availability, could the next generation of software defined networks provide an answer?

2 s Today- A Typical Design A completely resilient network can be expensive to achieve, however when the network is critical to a business, resiliency is needed. To address that need, typical network designs have evolved from single carrier deployments (diagram 1.1) to dual carrier solutions with dynamic failover to mitigate the risk of core failure and add additional resiliency into the network (diagram 1.2). This type of design can be expensive, and therefore typically only adopted where a loss or degradation of service is unacceptable. Diagram 1.1 Diagram 1.2 In recent years the adoption of Hybrid solutions, using IP Sec over the internet as back-up connectivity, has increased due to the high bandwidths available at a typically low cost (diagram 1.3). These designs do not include any inherent intelligence, it is simply a collection of pipes that provide transportation for your application. These s may now provide a required level of resilience at an acceptable cost but they are blind to an organisations applications and this has implications for the performance of the. Diagram 1.3

3 Traditional s - Application Performance Even when an organisation has invested in a resilient, the traditional network only determines the path that an application takes by predefined and inflexible rules known as routing protocols. Where intermittent errors and the degradation of the service, called brownouts, occur they can cause serious performance issues. Unfortunately, in this situation, the destination router can still be pinged, therefore the circuit is still deemed live, preventing effective failover to the back-up circuit. It s not only intermittent errors that cause poor performance of applications across the network. Consistently high bandwidth utilisation or sudden spikes in traffic, for example print traffic or FTP, can add congestion to the network affecting the performance of all applications. Quality of Service (QoS) has provided an element of intelligence, apportioning bandwidth to a particular application through defined profiles. However, given that these profiles are static, how do you determine what the right QoS profile is? And even if it is correct today, will it be tomorrow? How do you determine what the right QoS profile is? And even if it is correct today, will it be tomorrow?

4 QoS Profiles Voice Traffic Diagram 2.1 Voice is typically a fairly simple application to determine its usage as the bandwidth voice channels use is consistent (diagram 2.1). Multiply the required bandwidth for a single call by the number of concurrent voice calls and you have your profile. However what happens when there is a higher number of concurrent calls than the QoS profile setting? Here we see the amount of traffic bursting over the QoS profile (diagram 2.2). In this scenario any traffic over and above the designated profile will not have QoS provided, and potentially experience degradation and poor service. Diagram 2.2 Interactive Traffic If we then look at interactive traffic, we see a profile with many peaks and troughs. And so where should the QoS profile for this type of traffic be set? How much bandwidth should be apportioned when traffic levels aren t consistent? If you prioritise everything you are actually prioritising nothing.

5 Bulk Data And finally when bulk data, such as video, is sent along a link, at the point at which it uses all the available bandwidth, its performance is capped. And so, QoS does provide an element of sophistication within the network. However, as different types of traffic utilise the network at different times and QoS is a static tool, it cannot react and adapt to changes in traffic profiles or the needs of the application at a specific moment in time. Therefore, the typical responseto high bandwidth utilisation is to upgrade the bandwidth; however this is a short term and potentially expensive solution. With the recent developments within networking, intelligence can be added in to the to solve some of the issues seen in legacy network design. SD - The Next Generation of Networking Software Defined is a software defined overlay network that supports the use of Hybrid connectivity. It uses the underlying network as the carrier, whether that is MPLS, VPLS, Internet or a combination of technologies. SD is then overlayed, normalising the path across the underlay by tunnelling and optimising the end to end pathway based on application requirements, not destination IP address. With SD the network needs to understand: How the application is performing How it should be performing If the network is achieving the required performance How the application would perform over the secondary connection SD utilises the intelligent protocols within the edge routers and centralised controllers. The centralised controllers understand how the network is performing, based on predefined required application performance levels, and dynamically issues commands to the rest of the network to change the operation. This enables routers to make a path choice based on packet latency, jitter and loss rather than just reachability. This makes a network more reactive to issues which a routing protocol may miss and therefore results in a more consistent response for enterprise users.

6 Benefits of SD : Improved application availability and performance Deliver non-disruptive operations within your networking environment Reduction in cost, particularly back up connectivity The components of SD The term SD is a collective name for a suite of protocols utilised to deliver an intelligent overlay network solution. These protocols are detailed below: Dynamic Multipoint VPN (DMVPN): DMVPN normalises the connection, whether that be over MPLS or VPLS or Internet, and provides a tunnel to connect to the hub. It maps QoS markings onto tunnelled traffic to maintain prioritisation however as routers only need to reach the tunnel endpoint (hub) they don t need to interact with carrier routing protocols and so static routes are sufficient. Routing Protocols: Routing Protocols now run over the DMVPN tunnel, NOT the underlay network and so no route redistribution is required and they are not constrained to underlay routing requirements such as timers. This provides consistent routing metrics across the entire estate making internet failover dynamic and seamless. Traffic probes: Track how applications are responding by monitoring user traffic over the active path and how applications would respond over the inactive path by transmitting simulated traffic and report the results back to a Master Controller function. PfRv3: This new version of Performance Routing understands how applications are performing allowing Intelligent Path Control across the network as it responds to reachability, delay, jitter and loss. Applications are then routed based on application performance policies and traffic is load balanced based upon link utilisation. Netflow: This flow based reporting protocol allows monitoring tools to report on application flows. The term SD is a collective name for a suite of protocols utilised to deliver an intelligent overlay network solution.

7 What benefits can you expect to see with a Hybrid utilising SD? Application Performance and Availability With each day that passes reliance on IT grows, it is paramount that employees can access the applications they need to perform their roles and customers to engage with the business to buy from it. And so application availability and performance is critical. With a hybrid network utilising the intelligence of SD, the network can now automatically respond to any degradation in the performance of the application whether that be due to intermittent errors or bandwidth congestion, choosing the best available route providing non-disruptive operations. Cost Most developments in technology see reduction in cost as a benefit and within the hybrid there are clear areas where cost reduction is seen. reduce the cost of the back-up connectivity utilised within the network. This is particularly noticable within the global network where connectivity is expensive. Resiliency By utilising the underlying network as a mechanism, multiple carriers and access technologies can be seamlessly integrated into a single network. This ensures no single point of failure, whether that be due to a single circuit or a carrier s core network. Additionally, an overlay network can be implemented over a managed, and so where an existing network is in contract and performing poorly, SD can still provide benefit. The Next Generation is Here This development in networking is the biggest change in the industry since MPLS replaced Frame Relay. It is a major leap forward that can potentially provide dramatic performance benefits and cost savings for many organisations. For some it may seem like a future development, however this type of network solution is currently being adopted by many organisations. IT departments have to deliver services, demanded by their organisations, which are putting pressure on the underlying infrastructure. SD provides a solution to support the delivery of those services. By utilising all connections within a network, less congestion will be seen on the primary link. This can reduce the amount of bandwidth upgrades. As internet connectivity becomes a more viable access method this can potentially With a hybrid network utilising the intelligence of SD, the network can now automatically respond to any degradation in the performance of the application.