The SPP Tutorial

Introduction

This tutorial is designed to give a new SPP user some simple, step-by-step usage examples. This page and three others illustrate the main concepts required to get you started quickly and contain links to a number of auxilliary pages that will allow you to try more complex examples.

File:SPP-components.png

SPP Components (LC, CP, GPE, NPE)

Recall from Internet Scale Overlay Hosting that an advanced SPP developer writes code for a General-purpose Processing Engine (GPE) and a Network Processor Engine (NPE). Typically, a developer configures the SPP so that the NPE handles most data packets (the fastpath) while the GPE handles control and exception packets (the slowpath). The configuration process loads code into the GPE and NPE and installs filters in the Line Card (LC) to direct packets to the GPE or NPE.

In practice, we anticipate that most developers will write a prototype version of their router software using only the GPE and work with a SPP developer to transform the performance-critical parts of their GPE code to run on the NPE because programming an NPE is quite different than programming a general-purpose processor. That is, most developers will write a GPE-only prototype which captures the logic of their router software and pass this design to an advanced SPP developer to create a high-speed NPE-GPE version.

There are four main wiki pages in The SPP Tutorial:

• The SPP Tutorial: is this page which gives an overview of the other tutorial pages and covers administrative issues such as creating an account and getting a slice.
• The Hello GPE Tutorial: describes how to use the GPE to create a GPE-only prototype.
• The IPv4 Code Option Tutorial: describes how to use the IPv4 code option which uses an NPE to forward IPv4 packets and a GPE process packets terminating at the router (e.g., local delivery and exceptions).
• The Writing A Simple Code Option Tutorial: discusses how to develop a new code option.

The The Hello GPE Tutorial describes how to get information about interfaces; how to create slowpath endpoints for communicating with a process running on a GPE; and how to make a resource reservation. This tutorial will help you understand how to write a simple packet-processing program that will run on a GPE; i.e., a GPE-only prototype. The IPv4 Code Option Tutorial describes a simple example of using the IPv4 code option. This tutorial explains how to create fastpath endpoints, meta-interfaces, packet queues and IPv4 filters. Your code option can directly use all of these concepts except for IPv4 filters. However, your code option will need to use filters to direct incoming packets to packet queues. Seeing how it is done for the IPv4 code option will give you an understanding of how to design your filters. The Writing A Simple Code Option Tutorial goes through an example of a simple code option in which we first build a GPE-only prototype and how it would be transformed to use both an NPE and a GPE.

Requirements

This tutorial assumes that you are using a Linux operating system and have access to standard Unix tools. In particular, you will need:

1. An environment where you can compile code for a Linux operating system
2. An OpenSSH executable
3. The latest version of Java to run some monitoring software and traffic generators

The Java Run-time Environment (JRE)

Most of the tutorial can be done without the JRE. But it will be helpful in the IPv4 Code Option Tutorial.

First, determine if you already have JRE 1.6.0 or higher. Enter the following in a command-line window: java -version. If the response says that you are already running some version that is atleast 1.6.0, you can skip this step.

If you need to install the JRE, go to the Java download page http://java.com/en/download/manual.jsp and download the latest JRE for your platform by following the instructions posted at the Sun site. Note: You only need to download the JRE (less than 20 MB), not the entire JDK (Java Development Kit).

MAC Users

Follow this link Java Run-time Environment for the MAC OS for instructions.

Getting Started

You must get an SPP account before you can use the SPPs. The procedure is similar to the one used in PlanetLab except that SPP slices are administered through a special PLC (PlanetLab Central) site at http://drn06.arl.wustl.edu/. But the following PlanetLab procedure still holds:

• A Principle Investigator (PI) must create a slice for you.
• The PI must assign you to that slice.
• Then, you can add SPP nodes to your slice.

In a typical scenario, you (as an ordinary PlanetLab user) will use both normal PlanetLab nodes and SPP nodes. This requires that you get assigned both a normal PlanetLab slice and an SPP slice. Once you have been assigned to an SPP slice, you can log into the GPE of an SPP slice like any other PlanetLab node using ssh and develop a socket program as you would for any other PlanetLab node except for a few small differences:

• An SPP has multiple network interfaces if you want to use more than one interface.
• You must configure the SPP before you can use it.

The configuration process is fairly straightforward since a user typically customizes an existing configuration script to do the configuration.

Getting an SPP Account

• Create RSA key-pair
  • already have one if you have a PlanetLab account
• Fill out registration form
  • email address important
  • site
  • roles
• When registration has been accepted and you are assigned to a slice
  • login
  • upload RSA key (sidebar "Users => My Account")

What if you are a PI???