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);

}

We were discussing Riverbed Operating System (RiOS) technical concepts. With file servers and Email systems, RiOS has another optimization. This is the transparent pre-population. RiOS can transfer segments of file or email to the remote appliance before it is requested by any client. The initial access of a new file or email is therefore accelerated. When the first client calls in, the new file or email may not have made it across WAN and  the client could suffer a miss penalty. This is avoided if the file or email is pre-populated. There is no agent involved just that the segments are sent earlier. This is particularly helpful for emails with attachments. As emails arrive, their components are pulled across the WAN with all the RiOS acceleration techniques. In addition, for emails, RiOS keeps the Exchange TCP connection alive. This technique avoids big surges in email requests, such as the spikes that occur at the start of a work day and can bring the rest of a branch office's applications to a halt. Contrast this approach with the MAPI recommendation to use Cache Mode.  There is no data reduction techniques applied to the traffic in Cache Mode since there is nothing to accelerate email retrieval for users receiving large attachments or re-syncing their inbox. Consequently there is no benefits to network utilization with Cache Mode where as with references and segments used for deduplication and acceleration, there is significant improvement. Moreover, RiOS techniques can work with both Cache Mode as well as non-Cache Mode for Exchange servers. RiOS is therefore able to deliver optimizations for both OutlookAnywhere and MAPI clients. Finally, RiOS support for encrypted traffic optimizes it for deployments where Exchange Server has encrypted mode enabled by default.
RiOS doesn't avoid caching. In fact one of the performance improvement features for both HTTP and HTTPS traffic is that RiOS has an object-prefetch table to cache static web content which improves on reassembling from data references. This still allows for fresh transfers. In addition, RIOS supports the "If-Modified" request and "Not-Modified" responses which directs the clients to use their own local web browser cache avoiding WAN requests and minimizing delay for end-users. 

We were discussing Riverbed Operating System (RiOS) technical concepts. In addition to accelerating http and https traffic, RiOS devices respect the "if-modified" headers and respond with "not-modified" responses, so that the clients can retrieve the web content from its own local web browser cache. This eliminates roundtrips across the WAN and minimizes delay for end-users. This combined multi-layered approach works across different web content and application scenarios.
In addition, RiOS supports application streamlining for database server and application suites such as Oracle 11i and 12E-business suites. Here RiOS recognizes client session initiated Oracle Forms request and intercepts it. This is unscrambled from its native format to apply data streamlining and transport streamlining and optimize the client-server traffic bidirectionally.  This also accelerates the initial download of bulky java applets at startup time, allowing user login and startup to complete in seconds rather than minutes. Such techniques show 50X improvements.
Another advantage from RiOS is its compression that helps with application streamlining for Virtual Desktop Infrastructure. RiOS compression is better and achieves higher throughput.  Typical results show that twice as many Virtual Machines can be supported in addition to improving end user response time by 80%. Some applications like the Citrix desktop are even able to prioritize interactive activities like desktop input and display over less time sensitive operations like printing with the help of QoS markings. For jobs that are going to a spooler across the WAN, optimizations similar to CIFS can be applied. This alleviates the network retries and round trips.
To reduce the chattiness of requests and responses, sometimes requests can be replaced with a single large request that the server can choose to respond as available.

#codingexercise


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


{


If ( A== null) return 0;


Return A.NthRootProductOddRaisedPMinusQAndEvenRaisedPTimesQ(p, q);


}

We were discussing the Riverbed Optimization System (RiOS) technical concepts. We discuss some of the application streamlining modules. In particular we look at Disaster Recovery Acceleration.  The out of box acceleration for backup and replication operations already generated significant performance gains for data transfer jobs.  The traffic for such applications however is different and RiOS recognizes such large scale data transfers and makes use of it. Specifically, it applies system optimizations to enhance the throughput and handling of high-rate, high-volume backup data sets.
These enhancements enable acceleration of asynchronous replication solutions from a variety of vendors. Some integrations with Vendors have resulted in further optimizations. For example, RiOS devices are qualified by EMC to track and tune optimization for EMC SRDF on a per RDF group basis, thereby increasing the overall optimization and performance of SRDF traffic.
These additional optimizations also improve disk utilization, while also dynamically applying data reduction and compression algorithms. This results in throughput enhancements which further reduce the time required to complete a backup or replication operation beyond previous acceleration norms.
#codingexercise

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

{

If ( A== null) return 0;

Return A.NthRootProductOddRaisedPDividedQAndEvenRaisedPTimesQ(p, q);

}