Wide Area Network (WAN)

Challenges for WAN 

Data concentration, application integration, development trend of network flattening and multiple data centers requires an enterprise to establish a highly scalable WAN architecture. Multiple types of IT businesses (e.g. production, office and video) also require safe isolation of the network. However, the operation and maintenance costs of WAN will increase sharply and WAN resources will be wasted if one independent WAN has to be adopted for the transmission of each type of business. How can you realize WAN resource sharing and guarantee the safe isolation and service quality of various IT businesses is a challenge to enterprises in the establishment of a WAN.

 

WAN solution 

Highly scalable WAN architecture 

With a traditional flat WAN architecture, the addition of one subsidiary would necessitate corresponding network changes at all data centers. Similarly, the addition of one data center would necessitate corresponding network changes at all subsidiaries. For that reason, the network scalability is rather poor. The model of a traditional flat network is as follows: 

 

Figure1  Model of Traditional Flat Network

 

Add one layer of network center between the data center and the subsidiaries to be in charge of the WAN tandem and data transfer of the data center and subsidiaries. It not only alleviates the burden on the data center’s network access area, but also increases network scalability and data scheduling ability. When a new subsidiary is added, it is only necessary to connect the subsidiary to the network center without making any network change to the data center. When a new data center is added, it is only necessary to connect the new data center to the network center without making any network changes to any subsidiary. In addition, the data flows between subsidiaries do not need to pass through the data center. Instead, they are transmitted directly via the network center. The data flows between various data centers may also be transmitted via the network center without the need to establish a complicated data center internet. The model of network center WAN is as follows:

 

Figure2  Model of Network Center WAN

 

WAN virtualization designs 

MPLS VPN is a proven virtualization technology today. This technology has been massively deployed in the networks of operators. It can transmit the business data of different customers in the same trunk network with sound transmission quality. MPLS VPN virtualization technology may also be applied in a corporate WAN where it divides different business data into different VRFs for isolations on the router layer and guarantees transfer and service quality according to MPLS flags. Please see the following Figure for the WAN MPLS VPN solution:

 

Figure3

 

Conclusions 

The network center-based WAN architecture is applicable for enterprises that have multiple data centers and require network scalability. It also enables more flexible data flow scheduling and therefore is applicable for enterprises with a complicated business data flow model. MPLS VPN and other virtualization technologies are expected to improve WAN resource sharing and guarantee business data transmission security and service quality.