Layer 4–7 Service Graph Overview

Layer 4–7 Service Graph Overview 

Cisco ACI technology provides the capability to insert Layer 4 through Layer 7 functions using an approach referred as service graph, which streamlines the deployment and contract utilization for traffic control. Although it simplifies and automates the contract security part of the configuration, you still need to carefully design the network topology to ensure that traffic will flow through a service node.

A service graph is an ordered set of function nodes between a set of terminals, which identifies a set of network service functions that are required by an application. Service functions within a graph are automatically provisioned on a service device, based on the application's requirements. Briefly:

• A service graph is a technology to automate service chains.
• A service chain is a succession of functions (load balancing, SSL, firewall, and so on).
• So, a service graph is really a solution to automate the deployment of multiple functions to obtain a service chain.

The service graph is always associated with a contract between two EPGs. A service graph template is a sequence of Layer 4 to Layer 7 functions, Layer 4 to Layer 7 devices, or copy devices and their associated configuration, which can be provided by using function profiles. It represents a reusable, generic representation of the expected traffic flow that defines: