How WAN optimization technology mitigates network bottlenecks in data centers

Offline data and remote users may overload your Wan egress. To prevent network overload, some WAN optimization solutions are available.

Faced with the increasing network load, user scale, and real-time transmission applications in the data center, it is increasingly difficult to keep WAN lines fast and reliable. The strong demand for WAN services, coupled with the geographic distance between a large number of physical data centers and service providers, results in more serious bandwidth and latency problems. To solve the WAN bottleneck, you can choose to spend money to add expensive WAN connection channels to the data center, limit the network services of end users, or apply network optimization technology.

Wan bottlenecks and consequences

The Wan bottleneck slows down all workloads to a certain extent and affects end users. A typical cause of the bottleneck is big file data transmission between the data center and remote users.

Large files must be quickly cached, such as high-resolution images, audio and HD videos. Even formatting documents, slides, and other business files contain a large amount of data.

Real-time voice or communication traffic is generally transmitted through WAN connections, such as VoIP and Skype applications. Although the data has been highly compressed and requires very little bandwidth, these types of data must have a higher transmission priority than other types of data to ensure the quality of communication.

Business development usually requires more than one data center, and enterprises sometimes collaborate with outsourcing partners and public cloud providers. These satellite sites need to be connected to the primary data center. All of this data, including work access, data synchronization, data backup, disaster recovery storage, and other tasks that are easy to increase the WAN traffic load, lead to bottlenecks in the WAN link. When Synchronizing key data, the data center may even experience the impact of performance problems, which will reduce the performance of the online disaster recovery site and lead to data loss.

As a company's user base grows, any new remote employee, partner, customer, or all need to access the enterprise's data center, which will directly increase the Wan line load, especially when they transmit data-intensive or latency-sensitive data.

WAN optimization options

The Wan acceleration technology relieves the bottleneck of Wan utilization and usability. You can use these technologies to reduce WAN Traffic and optimize the bandwidth, latency, and data volume characteristics of the WAN.

Wan bandwidth usage Optimization

Deduplication and other data compression technologies can use fewer data packets for transmission. The deduplication technology is very popular in the storage field, and also has a major advantage in the network field. The data deduplication technology uses pointers with a small amount of data to reference a single original data segment instance to replace data at the byte level and eliminate the storage and transmission of duplicate data.

The local Wan cache is used to cache data transmitted by data nodes in branch offices or remote data centers over the WAN. When a transmission node receives a transfer request for the same data copy, the cache technology locates the request to the cache point of the precise data copy. Because the whole process does not need to resend the data that already exists in the local cache, there is no actual network data transmission operation, the WAN bandwidth usage will be reduced.

Wan latency Optimization

When data is transmitted between nodes with a large geographic distance, and the communication protocol takes time to confirm the data packets, and the data packets are lost due to network congestion, the WAN latency will become serious.

Wan cache can handle latency because obtaining data from the local cache is much faster than waiting for Wan to re-transmit data. Other technologies include the use of giant frames to enable more data transmission for each packet over the Internet-each packet can be up to 9000 bytes-and then enable selective validation, the receiver can be allowed to skip the unimportant packet validation process, thus reducing the delay caused by a large number of packet validation.

Compared to resending data packets after they are lost or discarded, the network can solve the packet loss problem in a forward-looking manner. After each few common data packets, a verification data packet with the ability to regenerate the lost data is added. The receiving end can reassemble the recently lost data packet based on the verification data, and generally no longer needs to request the other party to re-transmit the data. This greatly reduces the number of handshaking, retransmission, and re-transmission packets on poor or crowded WAN connections, and reduces the overall transmission latency.

Wan Traffic Optimization

You can achieve WAN optimization by organizing and scheduling network content. For example, Traffic Shaping can allow some applications to take precedence over others, or prevent some protocols and applications from occupying the WAN egress too much. You can also make sure that the bandwidth allocated to the VoIP service is higher than the bandwidth for downloading corporate videos or documents. Some network traffic shaping solutions can also be specific to users and applications for network control.

Some Wan-optimized devices can limit the number and transmission rate of connections, although this may make users who have been rejected unhappy. Rate limiting Technology ensures that applications or users can only use the limited maximum available bandwidth.

Select an appropriate WAN optimization vendor

WAN optimization equipment and software usually need to be deployed simultaneously at the sending and receiving ends. Well-known WAN optimization devices include Dell SonicWall WAN accelerators, Riverbed Steelhead, Cisco Wide Area Application Service (WAAS), F5 BIG-IP WAN optimization module, and SilverPeak NX hardware devices.

Many of these vendors also provide software-based WAN optimization solutions, such as Riverbed Virtual Steelhead, Cisco WAAS software, and SilverPeak VX Virtual software.

Of course, enterprises can also seek open-source WAN optimization products, including OpenNOP for Linux, WANProxy for data deduplication and TrafficSqueezer for Linux.

The features and functions of each WAN optimization solution are different. Therefore, before deploying WAN optimization technology for the production environment, select the most favorable combination of functions for your network analysis, it takes time for testing and verification.