Today we continue to read the Riverbed optimization systems. We started discussing the clustering options. We saw that even the series connected appliances can have a benefit. They make use of the of the feature of RiOS to pass traffic through unoptimized when the appliance is over limit. The next appliance therefore gets the chance to optimize it.
Moreover a single RiOS device can be plugged in-path on multiple network links. It can support simultaneous in-path deployment on 6 copper links or 6 fiber links, or even a mixture. In addition, the separation of server side and client side connection forwarding enables RiOS devices to co-operate across multiple redundant links when there are too many links for a single device or multiple links that are too far apart for a single device.
The deployment can also be out of path for redundancy and scale. In this mode, a pool of devices work together to handle incoming requests. When a device fails, the requests are failed over to the next device which handles the requests. This kind of deployment can be done using a Layer 4 switch, WCCP or PBR.
We now look at the notion of an interceptor. This is an optional role for Riverbed devices. It functions as a specialized connection distribution device for a bank of RiOS devices. In addition to functioning as an L4 switch, it can perform asymmetric routing. Besides it eliminates the need for WCCP or PBR which are difficult to configure. The interceptor is typically used for large Datacenter deployments where it can be deployed without requiring any static route configuration. The interceptor can  handle upto 1 million  concurrent connections. Moreover it can scale up to 12Gbps and maintain uniform performance over extended duration by monitoring the peers.
RiOS also supports warm standby between designated primary and backup devices. Using automated data store synchronization, both the data segments and the references created via Data Streamlining are copied from primary to backup appliance. On failovers, the backup functions as a hot data store and can begin serving immediately.

We were discussing Riverbed Operating System (RiOS) technical concepts. We were discussing the proxy file service which can improve performance by deferring current requests or permitting certain operations even if WAN connectivity is disrupted. PFS is an integrated local file server with support for disconnected operations and replication. It has a separate dedicated portion of disk space and does not interfere with the data streamlining activities with the remote server. This does not require any server side agent like Windows CIFS does and PFS works with any kind of host. Because its an optional feature it is not disruptive to the existing streamlining functions. Since PFS works as a local file server, it supports disconnected operations. Since it works in a dedicated mode, it can support replication to and from the remote datacenter. These are complementary to the benefits offered by the prediction and pre-population in the regular connections. In other words, the support for disconnected operations is in addition to the high performance acceleration system without the data integrity and communication issues of caching. PFS also schedules automatic updates of the  PFS shares on appliances, requiring no administrative oversight.
Next we look at high-availability clustering. This is helpful when deploying more than one RiOS devices in place of the existing RiOS device for high availability.  If the devices are place in series, then they take advantage of the fact that RiOS passes through unoptimized traffic when its performance limit is reached, handing over the opportunity to optimize the passed through traffic to the next member of the serial cluster.
#codingexercise


Double  GetNthRootProductOddRaisedPtimesQAndEvenRaisedPtimesQ (Double [] A,Double  p, Double q)


{



If ( A== null) return 0;



Return A.NthRootProductOddRaisedPtimesQAndEvenRaisedPtimesQ(p, q);



}

We were discussing Riverbed Operating System (RiOS) technical concepts. We now discuss the scalability of RiOS. The support for most network topology, no requirement to use tunnels, support for full mesh environments, no manual configuration, translates into broader scalability for large scale enterprises. Peering limits are nearly 4096 peers as compared to a few dozen with tunnel based solutions. In terms of throughput and connections, a RiOS device can support upto 40000 connections, optimizing traffic upto 10000 users. Clusters of devices can support upto one million concurrent connections and upto 4 Gigabits per second of throughput.
In terms of services, RiOS devices additionally provides customers with the capability to run software modules to run on the devices in a protected zone. By hosting the services and applications at the appliance, network level data interoperability is now available and this solution is called the Riverbed services platform. For example, The RSP helps customers by enabling branch services such as IP address management, video streaming and local print server. The RSP creates an extensible platform for multiple technology partners to deploy their services and applications without the need for dedicated servers and to deploy them at the edge. This ability to create a partition to host the RSP is done with the help of VMWare to provide a resource instance.
The RSP has additional capabilities such as the ability to add disk space without recreating RSP packages and the ability to put the RiOS appliance as a man-in-the-middle so that the interceptor based technologies can take full advantage of the RSP and the network.  In addition, RSP comes with a watchdog process that operates as a heartbeat to monitor each package and restart the Virtual Machines.
RiOS also provides an integrated local file server with support for disconnected operations and replication.Proxy File Service can improve performance by deferring current requests or permitting certain operations even if the WAN connectivity is disrupted.
#codingexercise

Double  GetNthRootProductOddRaisedPDividedQAndEvenRaisedPDividedQ (Double [] A,Double  p, Double q)

{


If ( A== null) return 0;


Return A.NthRootProductOddRaisedPDividedQAndEvenRaisedPDividedQ(p, q);


}

We were discussing Riverbed Operating System (RiOS) technical concepts. Today we look at QoS features of the product. We already discussed the network deployment and management streamlining options and found the RiOS devices to be appliances that expect no changes to the network. Now beyond the topology network considerations, let us review how QoS can be leveraged for bandwidth sensitive traffic. Traffic can be classified using the DS field (DSCP) This can be applied to both the optimized and pass-through traffic. The DS field values are passed by RiOS in completely transparent handoff  and hence existing QoS can be honored. In addition, new QoS DS fields can be defined with the WAN accelerated traffic.
The data-deduplication and data reduction  achieved with RiOS reclaims bandwidth and even undo existing QoS classifications which may no longer be necessary and can be replaced with simpler better re-classification. The RiOS devices that are deployed on the edge network can employ Hierarchical Fair Service class-of-service marking (H-FSC) and enforcement. This is used to improve both bandwidth and latency. H-FSC is a scheduling algorithm that can simultaneously support 1) hierarchical link sharing services, 2) guaranteed real-time service with provable tight delay bounds and 3) decoupled delay and bandwidth allocation. The latency-sensitivity of this approach is usually not found in many other techniques. If there are two different real-time critical applications and their bandwidth guarantees are met,  the queues could still become filled with traffic introducing jitter. In such cases, the ability to schedule application traffic based on latency and setting priority to that application traffic comes very useful with this kind of a scheduling algorithm.
Application visibility into network traffic is improved with the Riverbed "AppFlow" classification engine which utilizes a variety of technique and usually in combination. These techniques include :
port - based classification for applications
pattern-matching or application signature using patterns or magic numbers in protocol headers using regular expressions, byte or string matching.
protocol dissection - which involves detailed interpretation of the application protocol for contextual sub-classification or protocol attribute extraction
future - flow registration - where  a past occurrence of a flow is used to tag a future occurrence
behaviorial classification - where the behavioral classification relies on the detection of behavioral attributes of the network traffic using packet size, packet inter-arrival time, packet rate, data rate, and entropy calculations for a behavioral signature for an application.
decryption / decoding - where encoding, obfuscation or simple encryption may be used by applications


 

We were discussing Riverbed Operating System (RiOS) technical concepts. We were looking at the management streamlining functions. The controller and the console were used for this purpose. The central management console provides touchless feature. It provides aggregated or individual device reporting, group based configuration policies and scheduled operations. It also provides trends upto a years worth of data and drilldrowns for more granular data. This is a web interface that also facilitates over the wire software upgrades, global SSL certificate management and an easy to use QoS rules configuration interface. One of the things administrators look for when optimizing WAN traffic are those that are the heaviest users of bandwidth and they are referred to as "Top Talkers" . This is useful for both security monitoring as well as for accounting purposes.  Top Talkers together with NetFlow give a lot of WAN transparency.
While the console manages the devices, the Controller provides central management capabilities for the clients. The SMC enables easy deployment of mobile client software to remote users via MSI packages. It also integrates with Active Directory or LDAP for access control. The controller also provides license management, job scheduling and notifications to extend its administrative capabilities.
Next we look at the deployment options for RiOS. We mentioned the plug-in interface for RiOS appliances in any network topology and scalability due to its adherence to the networking fundamentals instead of specific architectures or setups such as tunnels. Consequently it requires less involvement during deployment. Even legacy devices and networks are compatible with this kind of appliances - since there are no changes expected or required from the network. Changes such as tunnel configurations, DFS changes, client drive mapping changes, plugins router configurations, route injection, or any other overhead required for competitive solutions are avoided. This implies that RiOS devices can be installed in networks as large as using satellite infrastructure or as connected as full mesh MPLS networks.

#codingexercise

Double  GetNthRootProductOddRaisedPDividedQAndEvenRaisedPPlusQ (Double [] A,Double  p, Double q)

{


If ( A== null) return 0;


Return A.NthRootProductOddRaisedPDividedQAndEvenRaisedPPlusQ(p, q);


}

We were discussing Riverbed Operating System (RiOS) technical concepts. We were looking at some of the management streamlining features. We review the console and controller to the device and the clients. In particular, we were looking at the reporting capabilities and host:port traffic can be labeled so that reports can included details stats on each by their names. The traffic from an appliance or a client or those monitored by a sniffer such as NetFlow can have detailed real-time flows including byte counts / per port. Traffic can be individually reported and segregated by optimized versus pass through traffic or aggregated over a NetFlow collector. The use of this third party tool also allows for avoiding correlation of data from multiple data sources.
Pass-Through traffic is usually UDP, VoIP, etc and is reported so that it can be reviewed for being pass-throngh. If the maximum capacity or the number of connections are exceeded, traffic may overflow to pass-through.
On the other hand, optimization traffic can quantify the improvements to WAN traffic. even on per feature basis such as application specific and TCP latency. The detailed report can show the number of roundtrips saved as well as the reduction in the data.
The tools used for this monitoring and management are the console and the controller. The central management console is a single console which appliances can auto-discover by a DNS lookup and register with to receive a pre-arranged configuration. Therefore, it allows to scale for as many appliances without requiring any tweaks. This is called touchless configuration. The console administrators can even use this to deploy configuration and policies on an individual, group or enterprise wide basis.

#codingexercise

Double  GetNthRootProductOddRaisedPPlusQAndEvenRaisedPDividedQ (Double [] A,Double  p, Double q)

{


If ( A== null) return 0;


Return A.NthRootProductOddRaisedPPlusQAndEvenRaisedPDividedQ(p, q);


}

We were discussing Riverbed Operating System (RiOS) technical concepts. We now look at some of the management streamlining features. As discussed, RiOS is deployed via appliances and clients. By their nature, they have minimal administrative overhead. Deployment is further simplified because it requires no change to servers, clients or routes. In addition, a central management console facilitates enterprise wide reporting, configuration and deployment options.
Let us look at the configuration and management tasks to see how the optimizations we talked about earlier are provisioned.  The RiOS devices support management via SSH command line interface or graphical HTTP/S interface.  The device needs to know the configuring interface IP, duplex information, subnet and management information, and then the device can be plugged into the network. Every device also supports SNMP traps and email alerts. SNMP traps include accounting and audit alerts such as user login/logout, configuration changes, TCPDump etc. The APIs allow the rest of the reporting and management actions.
RiOS introduces an auto-discovery capability that automates the establishment of optimization peering relationships through the enterprise.  This is a scalable approach that can grow with the size of the enterprise. Again, without the use of tunnels, auto-discovery enables easy integration with "any-to-any" networks, which is common to many of today's WAN architectures, thereby circumventing problems specific to tunnel based optimization technologies.
As opposed to the devices, the clients can number in hundreds or even in thousands. Since it requires an installer based deployment, this is easily automated via silent installation mode and mass installations.
The reporting information is not clouded by the application acceleration capabilities. RiOS enables naming and tagging to report the different traffic driving across WAN.  Reports can also include per application statistics for traffic that is passed through unoptimized.
#codingexercise
Double  GetNthRootProductOddRaisedPPlusQAndEvenRaisedPTimesQ (Double [] A,Double  p, Double q)
{

If ( A== null) return 0;

Return A.NthRootProductOddRaisedPPlusQAndEvenRaisedPTimesQ(p, q);

}