ALTO (Application layer traffic optimization)

Introduction:

ALTO (Application Layer Traffic Optimization) is a protocol that is used to improve network performance by providing applications with information about the network topology, including network congestion and link capacity. ALTO works by providing applications with a network map or directory, which includes information about the network topology and link state, allowing applications to make more informed decisions about where to send traffic. ALTO is designed to be extensible and can be used in a variety of network environments.

ALTO Architecture:

The ALTO architecture is divided into two main components: the ALTO server and the ALTO client. The ALTO server is responsible for collecting and distributing network information, while the ALTO client is responsible for using that information to optimize network traffic. The ALTO server communicates with network devices and applications using standardized RESTful APIs (Application Programming Interfaces), while the ALTO client can be integrated into a variety of network devices and applications, including routers, switches, and servers.

ALTO Network Map:

The core of ALTO is the network map, which provides applications with information about the network topology, including the location of network devices and link state. The network map is typically represented as a graph, with network devices represented as nodes and links represented as edges. The network map can be used to calculate the shortest path between two network devices, as well as to identify potential bottlenecks or congestion points in the network.

ALTO Cost Maps:

In addition to the network map, ALTO also provides cost maps, which assign a cost to each link in the network. The cost of a link is typically based on the available bandwidth, latency, and congestion on the link. Applications can use the cost map to make more informed decisions about where to send traffic, taking into account the current network conditions.

ALTO Query Types:

ALTO supports three main types of queries: endpoint property queries, network map queries, and cost map queries. Endpoint property queries are used to retrieve information about a specific endpoint, such as its location in the network. Network map queries are used to retrieve the entire network map, while cost map queries are used to retrieve the cost map for a specific network metric, such as bandwidth or latency.

ALTO Server Discovery:

To enable applications to discover ALTO servers on the network, ALTO uses a standardized service discovery mechanism based on the DNS-SD (DNS-Based Service Discovery) protocol. This allows applications to automatically locate the ALTO server on the network, without the need for manual configuration.

ALTO Extensions:

ALTO is designed to be extensible, allowing it to be used in a variety of network environments. To support this flexibility, ALTO provides a number of extension points that can be used to customize the protocol for specific use cases. Some common ALTO extensions include support for virtual networks, dynamic link metrics, and multi-tenant networks.

ALTO Use Cases:

ALTO has a wide range of potential use cases, including improving the performance of video streaming, file sharing, and online gaming applications. ALTO can also be used to optimize the performance of cloud-based applications, by providing information about the location and available resources of cloud providers.

Conclusion:

ALTO is a protocol that provides applications with information about the network topology, allowing them to make more informed decisions about where to send traffic. By providing a network map and cost maps, ALTO enables applications to optimize traffic flow and avoid network congestion. ALTO is designed to be extensible, allowing it to be customized for specific use cases, and has a wide range of potential applications, from video streaming to cloud-based applications.