WAN acceleration reduces the amount of traffic sent across the Wide Area Network and delivers information locally whenever possible. This improves the costs associated with application delivery - from staffing, infrastructure and facility costs to expenditures in application software and WAN bandwidth. In addition, WAN acceleration protects investments in business critical applications by ensuring that they meet end user performance objectives, and it minimizes risk of exposure by improving the performance and reliability of data backup, replication and recovery. As a result, WAN acceleration provides an extremely rapid return on investment, plus the intangible benefit of increased end user productivity and unsurpassed IT satisfaction.
First Generation of WAN optimization
Most often deployed as bandwidth band-aids, that providing short-term benefits on congested WAN links where it is too expensive to buy additional bandwidth. WAN optimizations rely on 2 underlying technologies which is compression and Quality of Service. (QoS)
Compression is used to reduce the bandwidth consumed by traffic traversing the WAN. This techniques is depends on the mix of traffic traversing the WAN. On average, most enterprises deploying compression technology will get around 50% improvements in WAN utilization which equal to doubling the effective WAN bandwidth.
Quality of Service
In an effort of maximize WAN utilization, most enterprises will oversubscribe their network. When demand exceeds the capacity of WAN link and traffic is competing for the same resource, the less important traffic may be used the bandwidth away from business-critical applications. To prevent such behavior, most 1st generation WAN optimization will implement QoS technique to classify prioritize traffic based on applications, user and other criteria.
Second Generation of WAN optimization
Application acceleration is a second generation of product that addresses the WAN optimization solutions. These application solutions can provide significant improvements by optimizing performance of specific application. Proxy and caching are used to simulate application server, enabling specific content to be delivered locally wit LAN-like performance. This technique provides a reasonable boost for static content but not work well for dynamic content. If performance gains are to be achieved, web caches have to be implemented in conjunction with other acceleration tools.
Third Generation of WAN Optimization
In addition to accelerating application performance, Local Instance Networking (LIN) addresses server by providing a mechanism for centralizing branch office infrastructure while localizing information delivery. It inspects all WAN traffic and stores a local instance of information in an application independent data store at each enterprise location. Each piece of information is not stored only once per location, enabling an appropriate sized of data to be hold.
LIN appliances deliver the performance of distributed servers, without complexity. It operates at network layer and completely transparent to all transport protocol. It also provides significant benefits to all enterprise applications. Local Instance Networking also puts an end to server sprawl, security, cost and compliance headaches that accompany it.
WAN Optimization techniques
WAN Optimization products accelerate a broad range of applications accessed by distributed enterprise users by eliminating redundant transmissions, staging data in local caches, compressing and prioritizing data, and streamlining chatty protocols. It also helps avoid packet delivery issues in shared WAN environments. The techniques used by WAN optimization product are;
Deduplication
This technique eliminates the transfer of redundant data across the WAN by sending references instead of the actual data. By working at the byte level, benefits are archived across IP applications.
Compression
This technique relies on data patterns that can be represented more efficiently and best suited for point to point leased lines.
Caching/Proxy
This technique relies on human behavior, accessing same data over and over again. It best suited for point to point leased lines, but also viable for internet connections and VPN tunnels. The effective use of web caching typically sees a bandwidth reduction of 15 - 30 percent on WAN links.
Protocol Spoofing
Bundles multiple requests from chatty applications into one and suitable for point to point WAN links.
Traffic shaping
Control data usages based in spotting specific patterns in the data and allowing or disallow specific traffic. It is suitable for both point to point leased lines and Internet connections and might be hard to keep current with ever expanding types of application.
Equalizing
This technique make assumptions on what needs immediate priority based on the data usage. It is an excellent choice for wide open unregulated internet connections and clogged VPN tunnels.
Connection Limits
This technique can prevents access gridlock in routers and access points due to denial of service or peer to peer connection. Best suited for wide open internet access links and also can be used in WAN links.
Simple Rate Limits
This technique can prevent user from getting more than fixed amount of data. It is best suited for remedying a congested internet connection or WAN links.
Advantages of using WAN acceleration
Improve performance and reliability of disaster recovery
Disaster recovery across wide area network (WAN) is difficult to achieve because the backup, replication and recovery involve the transfer of entire volume data which require significant amount of bandwidth. This will lead to high latency and subsequent database synchronization problems. WAN acceleration overcomes these problems by reducing the amount of data sent across the WAN during backup and restore processes and deliver information locally when possible to accelerate application response time.
Improve application performance across the WAN
There are limitation in WAN that makes it difficult to deliver application to remote and branch offices. Bandwidth is limited and very costly, latency will occur when communication taking place over long geographic distance, and congested network can cause packet loss. The back-off mechanism within TCP and chatty behavior of common application protocol make the situation even worst. By overcoming this limitation in wide area network, WAN accelerator can improve employee productivity and protect critical application while save on ongoing support costs and WAN bandwidth expenditures.
Facilitate data center consolidation
By facilitating the centralization of servers and storage, WAN accelerator can save money in infrastructure costs, software investments, WAN bandwidth and day-to-day operational expenditures.
Silver Peak
There are many products that offered the WAN optimization features; one of it is Silver Peak product. This company is founded in 2004 and privately held company that develops and enterprise-class Wide Area Network (WAN) acceleration appliances to improve network performance by improving application performance across the WAN.
Silver Peak offered and provides hardware devices that are complete for WAN acceleration. These products covered all the management tools that can facilitate data replication, network backup, disaster recovery, server centralization, and application delivery. Silver Peak's WAN Optimization product line is the NX Series of appliances. According to them, the solution provides benefits to all Internet Protocol applications, including TCP and non-TCP applications, as well as bulk transfer and real-time applications.
Silver Peak solution was designed from the ground up to support the scalability needs of large enterprises, while simultaneously remaining effective for smaller deployments. Unique features that ensure enterprise-grade scalability include;
Throughput
Silver Peak offers the highest WAN capacity of any WAN acceleration solution by delivering data reduction, compression, QoS, and latency/loss mitigation at high WAN speeds.
Storage capacity
Silver Peak leverages disk based WAN deduplication for superior memory retention and performance over time. The NX series appliances offer more that 10x local data store as alternative product, supporting up to 8 TB in a single appliance.
High flow counts
The Silver Peak solution is not limited by the number of transport layer flows in a network, as is the case with alternative solutions.
Wire speed encryption
Silver Peak leverages state of the art hardware to ensure that encryption does not adversely impact scalability and performance.
Application breadth
Silver Peak is the only WAN acceleration vendor to operate at the network layer of the ISO stack, providing data reduction, compression, and other technique across all enterprise applications, including SQL, VoIP and video.
Technologies used by Silver Peak's NX appliances.
Network memory
This technique uses advance fingerprinting technology to inspect all WAN traffic and stores a local instance of information at the appropriate enterprise location. Each piece of information is stored once per location which enables the Silver Peak appliances to hold weeks or months worth of data. Network memory will examine outbound packets to see if match is existed in the local instance at the destination location. If there is a match in the local instance, then the duplicate information will not be sent across the WAN and it will be sent to deliver the data locally. Network memory reduces the amount of data that traversing across WAN by several orders of magnitude and enables information to be delivered with LAN-like performance.
Compression
Cross flow payload compression ensure that the transmission of data across WAN is as efficient as possible by eliminating redundant information. This technique reduces overhead inherent to flows of small packets, as is the case with Voice over IP (VoIP).
Quality of Service (QoS)
Silver Peak NX Series appliances supports variety of Quality of Service techniques, including advance queuing and scheduling, as well as per application policy based decision-making and application tagging. These capabilities enable enterprises to deploy and prioritize a wide variety of business critical applications.
Latency and loss mitigation
Silver Peak solution uses protocol acceleration techniques, such as window size adjustment and selective acknowledgements to compensate for poor performance on high latency links. With Forward Error Correction that will add small amount of redundant information to the payload to recover packet loss at destination.
Secure content architecture
Silver Peak appliances protect all locally-stored and transmitted information from physical and network-level security breaches using 128-bit Advance Encryption Standard and IPSec tunneling.
Silver Peak's Product
Global Management System (GMS)
This product provides all the tools that necessary to centrally monitor, configure, and manage a Silver Peak's WAN products. It is standalone network appliances and have integrated SQL database, ensuring easy setup and maintenance in any enterprise environment.
GMS ensures fast and accurate configuration of Silver Peak's products. Silver Peak also provides automated deployment wizard to assists configuration process. This product also facilitates day-to-day administrative tasks across an entire distributed network, including scheduled configuration backups, automatic software updates and other vital device management functions.
GMS also provides centralized monitoring point that has easy to use dashboards that provide real-time information. It also has extensive reporting capabilities that assist with capacity management, network planning, auditing, troubleshooting, and SLA enforcement. Real-time and historical reports are available including traffic statistic. All of this information can be exported from GMS for easy manipulation and long term storage.
NX Appliances products information
NX-1000
NX-2000
NX-3000
NX-5000
NX-7000
NX-8000
NX-9000
WAN capacity
4Mbps
8Mbps
20Mbps
50Mbps
155Mbps
500Mbps
1Gbps
Certified Connection
8000
64000
64000
64000
128000
256000
256000
Local Data Storage
1 x 500GB
2 x 250GB
2 x 500GB
8 x 250GB
12 x 250GB
16 x 500GB
16 x 500GB
Power Supplies
Single
Single
1 + 1 Redundant
2 + 1 Redundant
2 + 1 Redundant
2 + 1 Redundant
2 + 1 Redundant
AES Disk Encryption
Real-time
Real-time
Real-time
Real-time
Real-time
Real-time
Real-time
IPSec Traffic Encryption
Real-time
Real-time
Real-time
Real-time
Real-time
Real-time
Real-time
Redundant Deployment
VRRP or WCCP 1:1, N + 1
VRRP or WCCP 1:1, N + 1
VRRP or WCCP 1:1, N + 1
VRRP or WCCP 1:1, N + 1
VRRP or WCCP 1:1, N + 1
VRRP or WCCP 1:1, N + 1
VRRP or WCCP 1:1, N + 1
Form Factor
1 RU
1 RU
2 RU
3 RU
3 RU
3 RU
3 RU
PRICE
USD$4995
USD$9995
USD$17995
USD$44995
USD$64995
USD$129995
USD$259995
Deployment guide for Silver Peak NX Series appliances
Silver Peak NX Series appliances require a minimal amount of network configuration and absolutely no client, server, or application reconfiguration. Silver Peak appliances are deployed in each of a distributed enterprise network and typically sit "behind" WAN router. The appliances support variety of different installation modes and robust fallback mechanisms such as;
Figure 1.0 Example of Silver Peak NX series deployment
In-Line
Figure 1.1 In-Line type of deployment
Silver Peak NX Series appliances is inserted in-line between WAN router and the Ethernet switch on the LAN side of the network. This type of deployment will accelerates traffice flows that match its ACL (access control lists) and all other traffic passes through the appliances unmodified.
Out of path
This type of deployment is not in the direct path of the network traffic, so a network traffic redirection technique is used to forward traffic to the appliance.
Policy-Based-Routing (PBR) Redirection
This is a common technique to redirect flows of traffic using an ACL and a policy instead of normal routing table lookups. The appliances intercepts only those packets that have been redirected to it.
Figure 1.2 Out of Path type with Policy-Based-Rourting (PBR) Redirection deployment
Web Cache Coordination Protocol (WCCP)
This type is originally designed to support the redirection of HTTP traffic to web caches and to support the redirection of any TCP of UDP connections to appliances participating in WCCP Service Groups. Silver Peak appliances intercepts only those packets that have been redirected to it, accelerating traffic flows that match its ACL.
Figure 1.3 Out of Path type with Web Cache Coordination Protocol (WCCP) deployment
Virtual Router Redundancy Protocol (VRRP) Peering to WAN router
The easiest way to redirect traffic is to make the Silver Peak appliances the default gateway for all the clients and servers on the LAN side of the network. This can be done by configuring IP address of Silver Peak appliances the same as the existing default gateway address.
Figure 1.4 Out of Path with Virtual Router Redudndancy Protocol (VRRP) deployment
Silver Peak Products Benefits
Benefits
Explaination
Technology Features
Enterprise Scalability
Can support form remote office size to large data centers
Not limited by TCP flows
NX Series appliances renge from 250GB to 8TB of local storage
NX Series appliances support 2Mbps to 1Gbps of WAN bandwidth capacity
64-bit hardware architecture
LAN-like Performance
For optimal application delivery across a distributed enterprise
Information delivered locally when possible
Only deltas traverse the WAN when delivering similar data
Advance payload and header compression
Latency/loss mitigation, including TCP acceleration, and adaptive FEC
Quality of Service
Complete Application Tranparency
No modification required to clients, servers, or network infrastructure
Byte-level visibility works across all applications
Secure data Protection
Data is secured whether in the box or across the WAN
Real-time encryption of disk drives using 128-bit AES
IPSec tunneling between NX Series Appliances
Network Resiliency
Provide maximum application performance with maximum up-time
NX series appliances feature RAID with redundant power supplies
Fail-to-wire
Redundant deployment options.
Manageability
Fro rapid deployment and cost effective operations
Easy-to-use setup wizard
Intuitive User Interface for configuration, monitoring, management and reporting
Silver Peak accelerate SQL
When SQL task are performed across the WAN, they are some factors that can affect perrormance, including limited bandwidth, high latency, and packet loss. Silver Peak provides a variety of optimization techniques that improve the performance and relaibility of most SQL operations, such as;
SQL queries across the WAN
Database backups and copies
SQL replication, such as Double Take, Neverfail and XOsoft
Fault tolerance, including connectivity to standby SQL servers
Database recovery
Silver Peak typically provides a 3x to 20x improvement on SQL queries, and 10x to 50x improvement on database backups and SQL replication. Given the type of data being transferred, peak improvements can exceed 100x.
Silver Peak accelerating web applications
Web application have become richer over time, including more interactive data with larger embedded images and file attachments. The performance of web applications is further debilitated by programming inefficiencies. Up to 80% web content generated by enterprise applications is treated by web servers as dynamic content. Dynamic content is not cacheable by the browser or cache proxies because it is generated by the application server and repeatedly sent across the WAN to client browsers every time it is requested. Silver Peak appliances accelerate and secure all Web-based enterprise applications and portals through several optimization tehcniques;
WAN deduplication
The first time a HTTP object is requested, the informations is compressed and sent over WAN. When a browser later requests the same object from the server that dynamically creates the content, a Silver Peak NX appliances recognizes the information stream and delivers the information locally. Network Memory remembers and recalls byte stream patterns by operating at the network layer and remaining application transparent. Every client request is passed through to the server and the data received by the client is always fresh, not a cache copy that can be out-of-date.
Improving latency
Silver Peak uses additional Network Accelearation tools to improve HTTP performance, including window scaling, selective ACK, and fast retransmit. This speeds up web portals and business critical web applications, particularly when they are accessed over higher latency links.
Packet coalescing
Silver Peak uses packet coalescing to repackage multiple smaller packets into a single larger packet. Web application will creates a stream of small packet on the WAN, each of which requires a TCP acknowledgement. By coalescing a series of short packets into a single larger packet, and compressing both the header and payload, Silver Peak reduces the impact of latency in these environments.
Header compression and Cross-flow payload compression
Silver Peak uses crossflow payload and header compression to reduce the amount of HTTP traffic traversing the WAN, improving performance even on the first transmission.
GLOSARY
Advance Encryption Standard (AES): A data encryption scheme which uses 3 different key sizes (128bit, 192bit, 256bit) to protect electronic data.
Chatty behavior: situation where servers and other network devices constantly announce their availability over the network and this can lead to network overhead.
Compression: Process of encoding information using fewer bits and specific encoding schemes
Deduplication: A method for compressing data by storing only changes to the original data
Disaster Recovery: A protocol to recover lost computing-system usage (application), data and data transactions committed up to the moment of system loss.
Fail-to-wire: A condition where the network will bypass the device if the device is happen to be powered off or fails.
Forward Error Correction (FEC): A system of error control for data transmission, whereby the sender adds redundant data to its messages.
IPSec: Internet protocol security is a protocol suite for securing Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a data stream.
Latency: Any kind of delays typically incurred in processing of network data.
Loss mitigation: literally mean to reduce loss.
Protocol spoofing: A method to improve performance in situation where an existing protocol is inadequate.
Quality of Service: The ability to provide different priority to different applications, users, or data flows, or to guarantee a certain level of performance to a data flow.
Redundant Array of Independent Disk (RAID): A technology that allows high levels of storage reliability from low-cost and less reliable PC-class disk drive components, via the technique of arranging the devices into arrays for redundancy.
Resilience: The ability to provide and maintain an acceptable level of service in the face of faults and challenges to normal operation
Server Sprawl: A situation that can occur in data center where a disproportionate amount of the physical server machines are running at very low utilization and wasting a lot of resources.
Synchronization: Multiple processes join up or handshake at a certain point, so as to reach an agreement or commit to a certain sequence of action.
Traffic shaping: A method for smoothing the bursty traffic rate that might arrive on an access virtual circuit so as to present a more uniform traffic rate on the network and comply with the traffic contract.
Tunneling: A type of technology that enable one network to send data via other network's connections.
Utilization: The capability of the software product to use appropriate amounts and types of resources
Virtual Private Network: A network that is set up for use by a limited number of individuals, such as employees of a company, operating over a large area.
Web caching: A process of caching a web documents to reduce bandwidth usage, server load, and perceived lag.
