Routing, Switching, and Load Balancing Solutions

In data centers today, a three-tiered architecture has access, aggregation, and core layers, as described below.

Access Switches

The access layer is the first tier or edge of the data center. It is the place where end devices such as servers and storage attach to the wired or wireless portion of the network. The servers are front-end to the access and back-end to the Ethernet- and Fibre Channel-based storage.

Aggregation Switches

The aggregation layer has a unique role: it acts as a services and control boundary between the access and core. Both access and core are essentially dedicated special-purpose layers. The access layer is dedicated to meeting the functions of end-device connectivity and the core layer is dedicated to providing non-stop connectivity across the entire network. The aggregation layer, on the other hand, serves several functions. It is an aggregation point for all of the access switches; it can be scaled out and acts as an integral member of the access-distribution block providing connectivity and policy services for traffic flows within the access-distribution block. As an element in the core of the network, it participates in the core routing design.

Core Switches

The core layer provides a very limited set of services and is designed to be highly available and operate in an always-on mode. The core layer is a gateway with high-speed connectivity to external entities, such as the WAN, intranet, and Internet. The data center core is a Layer 3 domain in which efficient and expeditious forwarding of packets is the fundamental objective. To this end, the data center core is built with high-bandwidth links (10 GbE) and employs routing best practices to optimize traffic flows. Note that the core should not implement any complex policy services, nor should it have directly-attached user or server connections. The core should have a minimal control plane configuration combined with highly available devices configured with the physical redundancy to provide for non-stop service.

Load Balancers

**A10 Networks AX Series Load Balancer**

Load balancing is a computer networking methodology to distribute workload across multiple servers, network links, processing systems, disk drives and other IT resources. This helps IT network designers achieve balanced resource utilization, maximizes network throughput, and avoids overloading any particular asset. In addition, by leveraging load balancing, network designers increase reliability by hedging against single points of failure by creating multiple paths for data flow and processing in case any single point (i.e. individual server or switch) fails.

As a consultancy, PTS performs comprehensive needs analysis, performs a complete assessment of possible solutions from best-in-class manufacturers, and designs the most appropriate switching approach to meet the client requirements prior to recommending a switching solution from any particular manufacturer. Deployment scenarios range from internet backbone to server aggregation to collapsed enterprise backbone to aggregation to access.

To learn more about PTS recommended Routing & Switching Solutions, contact us or visit (in alphabetical order):